COMMUNICATIONS MITTEILUNGEN
FROM THE DER
KONKOLY OBSERVATORY STERNWARTE
OF THE DER UNGARISCHEN AKADEMIE
HUNGARIAN ACADEMY OF SCIENCES DER WISSENSCHAFTEN
BUDAPEST - SZABADSAGHEGY
No. 77.
L. SZABADOS
PHOTOELECTRIC UBV PHOTOMETRY
OF NORTHERN CEPHEIDS, III
BUDAPEST, 1981
ISBN 963 8361 02 6 osszkiadas
ISBN 963 8361 11 5 III, resz
HU ISSN 0324-2234
Felelos kiado: Szeidl Bela
PHOTOELECTRIC UBV PHOTOMETRY OF NORTHERN CEPHEIDS, III
ABSTRACT
New UBV photoelectric observational data on 25 northern Cepheids with periods
longer than 10 days are presented. The period changes and the variations in the light curve
of the observed Cepheids are investigated.
Almost half of the programme stars show continuous period change (parabolic O-C
curve). Among the Cepheids in binary systems YZ Aur, SV Per and perhaps AN Aur show a
period jump and a subsequent rejump to the earlier value of the period. The apparent
period changes due to orbital motion around the common centre of gravity can be seen in RW
Cam, X Cyg, SZ Cyg and T Mon. The orbital period of RW Cam is about 6600 days. The only new
case of secular light curve variation is observed in AN Aur.
INTRODUCTION
This paper is the third and last part of a series dealing with the new UBV
photometry of northern Cepheids performed at the Konkoly Observatory, and it contains the
observational data and O-C diagrams of Cepheids with periods longer than 10 days. The
previous parts of this survey covered Cepheids with periods shorter than this limit
(Szabados, 1977 and 1980; hereinafter these papers are referred to as Paper I and Paper II,
respectively).
The main purposes of this survey have been outlined in the introductions to Papers
I and II. With the long period Cepheids the most important factor is the knowledge of the
period changes because the long period Cepheids tend to exhibit strong period changes. The
investigation of the period changes of Cepheids in binary systems is also very important
because the O-C diagrams of these variables may show two kinds of peculiarities, viz. a
rejumping period and an apparent period change due to the orbital motion (see pp. 112-114
of Paper II).
During the course of this last part of the work 25 Cepheids were observed. Of these
variables, 13 were observed in three colours of the UBV system, the other 12 in B and V
lights only.
THE OBSERVATIONS
The stars dealt with in this programme were selected from the General Catalogue of
Variable Stars (Kukarkin et al., 1969-1970) with the restrictions that their declination
should be north of 0° and B magnitude (or m_{pg} for lack of photoelectric observations) at
light minimum brighter than 12.5m . This sample contains Cepheids of both populations with
a period greater than 10 days. Only the variable star RU Cam was omitted because of its
well known photometric and spectroscopic peculiarities which raise doubts as to its
belonging to CW variables. Moreover, RU Cam has been regularly observed since 1967 at
Konkoly Observatory by the members of the Variable Star Department. A detailed analysis on
this star will appear in due course.
Table 1 The programme
Page Page
Star N Col. obs. rem. Star N Col. obs. rem.
SZ Aql 20 UBV 7 66 VX Cyg 22 BV 13 70
TT Aql 23 UBV 7 47 BZ Cyg 21 BV 14 20
RX Aur 17 UBV 7 41 CD Cyg 21 UBV 14 64
SY Aur 19 UBV 8 21 AA Gem 13 BV 15 40
YZ Aur 20 BV 8 68 zeta Gem 16 UBV 15 24
AN Aur 17 BV 9 29 AP Her 32 BV 16 31
RW Cam 20 UBV 9 62 Z Lac 20 UBV 16 35
RW Cas 21 BV 10 51 T Mon 12 UBV 17 72
RY Cas 20 BV 10 43 SV Mon 17 UBV 17 56
SZ Cas 18 BV 11 45 SV Per 19 BV 18 38
X Cyg 24 UBV 11 58 VX Per 16 UBV 18 37
SZ Cyg 19 BV 13 54 SV Vul 23 UBV 18 76
TX Cyg 23 BV 13 49
The stars investigated are listed in Table 1. The number of observations on each
star, the colours, serial numbers of the pages where the individual observations and the
O-C diagram with additional remarks on the given star can be found are indicated in the
successive columns. The total number of observations is close on 500. The observations were
made between 1977 and 1980 except for Z Lac. This latter star was observed several years
earlier among the stars in the second group of the programme stars, because of the
similarity of its coordinates with the shorter period Cepheid RR Lac.
Table 2
Variable Comp. V B-V U-B Check V B-V U-B Remark
SZ Aql + 0° 4090 8.94m 1.42m 1.42m + 0° 4088 6.76m 1.51m 1.75m
TT Aql + 1° 3905 7.56 0.48 -0.02 + 1° 3911 8.89 0.74 0.47
RX Aur +39° 1159 8.13 1.15 1.02 +39° 1157 8.39 0.15 -0.43
SY Aur +42° 1190 8.81 1.63 2.04 +42° 1192 9.17 0.33 0.07
YZ Aur +39° 1221 9.66 1.21 +40° 1214 9.24 1.33
AN Aur +40° 1126 11.11 0.45 +40° 1132 10.35 0.51
RW Cam +58° 670 9.13 1.22 1.00 +57° 755 9.19 0.96 0.77
RW Cas +56° 311 9.70 1.31 +57° 362 8.99 0.17
RY Cas +57° 2824 9.79 1.41 +57° 2823 9.58 0.29
SZ Cas +58° 466 9.94 1.34 +58° 461 9.74 0.46
X Cyg +35° 4219 7.42 0.65 0.12 +35° 4282 6.64 1.61 2.10
SZ Cyg +46° 2971 9.80 1.29 +46° 2976 9.46 1.13
TX Cyg +41° 3958 10.25 1.20 see Fig.1 10.68 0.88
VX Cyg +39° 4380 9.78 1.19 +40° 4365 9.63 0.45 1
BZ Cyg +44° 3578 9.90 0.65 +44° 3572 9.64 0.47 2
CD Cyg +33° 3734 8.92 1.07 0.84 +33° 3730 9.38 0.32 0.08
AA Gem +26° 1083 9.89 1.39 +26° 1080 10.51 0.14
zeta Gem +22° 1645 3.52 0.34 0.04 +16° 1443 3.57 0.10 0.10
AP Her +15° 3592 9.60 1.17 +15° 3586 9.33 0.98
Z Lac +55° 2791 8.79 1.05 0.83 +55° 2792 8.71 0.24 -0.06
T Mon, SV Mon + 6° 1253 7.74 1.03 0.49 + 6° 1254 7.37 1.57 1.52
SV Per +41° 975 9.61 1.14 +41° 973 9.84 1.03
VX Per +57° 479 9.01 0.68 0.06 +58° 375 8.87 0.73 0.11
SV Vul +27° 3523 6.93 0.66 0.06 +27° 3516 6.85 0.69 0.12
Remarks: 1 The comparison star has a faint companion
2 The check star is double
A full description of the observational technique, and the telescope and filters
used can be found in Paper I (p. 6). During the course of the present part the observations
were performed using the 24" telescope only.
The V magnitudes and colour indices of the comparison and check stars are listed in
Table 2. The tie-in observations were made with the aid of UBV standard stars taken from
the catalogue of Blanco et al. (1968). All the comparison and check stars are BD stars
except for the check star for TX Cyg. This latter check star can be identified using the
chart in Fig. 1. The size of this chart is 45'x45', north is at the top; the letter a
denotes the comparison star and the star marked b is the check one.
Figure 1 Identification chart for TX Cyg
Table 3 contains the observations in alphabetical order of the constellations.
Some unpublished observations made by Prof. L. Detre in 1953 and by Dr. J. Abaffy in 1967
are also listed in Table 3. Unfortunately, since the comparison stars used by them are
unknown in several cases these two sets of observations have not been transformed to the
standard system, and only the magnitude differences are given in the instrumental system.
Table 3 The observations
SZ Aquilae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3647.526 9.22 1.82 3761.289 8.65 1.57 1.43
3679.478 9.14 1.79 3763.315 8.88 1.69 1.44:
3693.440 8.69 1.65 1.48 3798.223 8.96 1.72: 1.61:
3701.422 9.04 1.62 1.28 3803.213 9.17 1.66 1.42
3703.518 8.77 1.46 1.03 3809.239 8.31 1.32 0.94:
3705.406 8.20 1.20 4049.529 8.34 1.32 1.19
3714.383 9.15 1.83 1.67 4050.470 8.41 1.35 1.21
3743.400 8.58 1.51 1.39 4102.330 8.47 1.45
3747.311 9.00 1.76 1.71 4113.313 8.95 1.53 1.23
3749.405 9.25 1.85: 4150.264 8.04 1.07 1.04
TT Aquilae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3647.546 6.77 1.13 0.82 3743.412 6.71 1.10 0.83
3679.456 7.28 1.47 1.33 3747.298 7.19 1.44 1.33
3690.414 6.93 1.28 1.07 3749.417 7.45 1.55 1.50
3701.407 6.65 0.98 0.76 3772.260 6.89 1.24 0.94
3703.506 6.85 1.24 1.06 3781.289 7.37 1.33 1.00
3705.394 7.10 1.39 1.18 3809.228 7.33 1.33 0.99
3707.443 7.32 1.47 1.36 4050.482 7.24 1.44 1.32
3714.371 6.67 1.00 0.63 4126.301 7.19 1.25 0.98
3722.411 7.52 1.60 1.52 4129.330 6.79 1.20 0.83
3724.437 7.56 1.50 1.60 4140.320 7.08 1.16 0.84
3737.322 7.55 1.65 1.61 4155.238 6.65 1.03 0.63
3739.405 7.40 1.42 1.08
RX Aurigae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3438.607 7.76 1.12 0.74 3607.296 7.73 0.93 0.56:
3483.653 7.60 0.97 0.72 3777.536 7.98 1.15 0.84
3490.524 7.81 0.95 0.53 3789.619 8.02 1.14 0.88
3599.311 7.55 0.96 0.57 3791.574 7.95 1.03 0.67
Table 3 (cont.)
(RX Aur)
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3830.399 7.37 0.83 0.54 4143.473 7.41 0.80 0.53
3911.445 7.35 0.78 0.56 4162.535 8.02 1.11 0.74
3926.434 7.73 1.06 0.74 4203.324 7.50 0.98 0.59
3957.302 7.43 0.80 0.47 4251.332 7.63 1.04 0.70
3966.312 7.86 1.04 0.59:
SY Aurigae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3424.635 9.12 1.00 0.68 3878.315 9.36 1.21
3425.639 8.91 0.91 0.66 3928.355 9.27 1.22 0.81
3438.628 8.93 1.03 3931.279 9.29 1.09 0.71
3460.493 9.12 1.11 3956.290 8.98 1.05 0.79
3483.620 9.36 1.21 0.89 3957.315 9.09 1.15 0.78:
3599.328 8.76 0.92 0.72: 4132.622 9.38 1.22 0.75
3789.485 9.27 1.01 4157.507 8.74 0.91 0.59.
3791.601 8.84 0.93 0.64 4166.471 8.89 0.95 0.72:
3803.393 8.86 0.93 0.77: 4203.346 9.37 1.24 0.87
3849.454 9.33 1.14 0.78
YZ Aurigae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3420.620 10.25 1.43 3849.411 10.52 1.47
3423.569 10.46 1.60 3928.385 10.14 1.33
3424.584 10.52 1.67 3931.403 10.27 1.58
3425.593 10.65 1.66 3956.275 10.75 1.56
3483.602 10.76 1.47 4108.560 9.98 1.22
3490.540 10.00 1.28 4132.604 10.41 1.53
3598.349 9.93 1.20 4143.469 9.96 1.21
3777.551 10.56 1.33 4167.460 10.28 1.56
3791.586 10.72 1.68 4215.393 10.09 1.27
3793.617 10.53 1.53 4251.315 10.27 1.25
Table 3 (cont.)
AN Aurigae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3424.603 10.73 1.34 3803.408 10.81 1.40
3425.616 10.49 1.23: 3926.386 10.76 1.43
3438.590 10.21 1.14 3928.369 10.79 1.36
3483.569 10.68 1.40 3931.394 10.30 1.21
3490.470 10.24 1.09 3935.298 10.50 1.36
3524.252 10.57 1.40 4157.487 10.30 1.18
3777.514 10.25 1.21 4167.445 10.29 1.18
3789.513 10.25 1.27 4251.351 10.19 1.17
3793.578 10.79 1.44
RW Camelopardalis
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3438.520 8.88 1.47 0.91 3849.437 8.94 1.50 0.92:
3481.412 8.32 1.34 0.92 3878.332 8.58 1.42 0.98:
3483.674 8.52 1.44 1.02 3926.451 8.52 1.42 1.00
3560.320 8.47 1.24 0.82 3928.337 8.65 1.45 1.03
3777.441 8.39 1.35 1.03: 3935.328 8.84 1.41 0.83
3788.565 8.74 1.37 0.82 3956.303 8.20 1.27 0.91
3789.442 8.75 1.37 0.88 3966.325 9.00 1.46 0.96
3791.557 8.17 1.21 0.89: 4143.444 8.78 1.52 0.99
3803.376 8.92 1.44 0.90 4162.510 9.01 1.48 0.89:
3830.367 8.70 1.53 1.01 4167.413 8.55 1.34 0.85
Observations in 1967
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9777.469 +0.203 1.070 1.929 9791.442 -0.021 0.832 1.634
9780.574 +0.392 1.234 1.755 9806.406 -0.112 0.684 1.265
9782.628 +0.180 1.003 1.410 9821.321 -0.240: 0.455: 0.810:
9786.528 -0.441 0.147 0.864 9833.334 +0.117: 0.820:
9790.625 -0.072 0.754 1.575
Table 3 (cont.)
RW Cassiopeiae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3420.524 9.10 1.35 3830.246 8.60 0.92
3424.488 9.59 1.59 3837.421 9.44 1.52
3437.400 9.34 1.48 3873.362 9.41 1.32
3438.471 9.48 1.55 3928.249 9.70 1.56
3489.314 9.23 1.19 3931.265 9.49 1.41:
3490.333 8.58 0.91 4108.500 9.50 1.51
3560.272 9.69 1.52 4113.377 8.81 1.21:
3788.522 8.90 1.17 4157.391 8.79 1.08
3789.456 9.01 1.28 4166.370 9.73 1.62
3791.529 9.24 1.44 4167.302 9.62 1.46
3800.288 8.98 1.14
Observations in 1967
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9759.590 -0.091 +0.919 2.11 9781.553 -0.343 +0.699 2.13
9762.589 -0.855 -0.153 9783.424 -0.127 +1.043 2.08:
9763.491 -0.751 +0.022 0.928 9786.507 +0.278 +1.458
9769.530 +0.006 +1.152 2.61 9787.500 +0.261 +1.440
9770.435 +0.120 +1.346 2.82 9790.490 -0.108 +0.844 2.03
9776.515 -0.776 -0.089 0.761 9791.501 -0.957 -0.351 0.450
9780.518 -0.492 +0.475 1.648
RY Cassiopeiae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3420.505 10.31 1.62: 3777.572 9.48 1.13
3424.469 9.71 1.22 3798.274 10.30 1.42:
3438.456 9.38 1.13 3837.435 9.68 1.19
3483.328 10.05 1.40 3878.242 9.82 1.45
3489.295 9.77 1.33 3928.241 10.07 1.63
3490.306 9.90 1.42 3931.254 10.35 1.57
3524.261 9.55 1.22 4054.508 9.95 1.33
3743.562 9.72 1.29 4066.470 10.05 1.42
Table 3 (cont.)
(X Cyg)
J.D.hel. DeltaV Deltab J.D.hel. DeltaV Deltab
2430000+ 2430000+
4577.415 -0.319 -0.127 4606.332 -0.691 -0.909
4579.432 -0.063 +0.252 4607.510 -0.552 -0.700
4580.410 +0.094 +0.453 4608.495 -0.479 -0.495
4581.427 +0.226 +0.535 4609.549 -0.331 -0.309
4583.448 +0.314 +0.620 4610.421 -0.259 -0.140
4584.551 +0.194 +0.458 4611.397 -0.178 +0.050
4585.375 +0.025 +0.102 4614.419 +0.180 +0.539
4587.527 -0.509 -0.686 4618.483 +0.012 +0.019
4588.377 -0.825 -1.105 4619.394 +0.040 +0.022
4589.360 -0.863 -1.114 4619.570 -0.002 -0.050
4590.425 -0.656 -0.836 4620.539 -0.579 -0.874
4591.419 -0.552 -0.590 4621.622 -0.839 -1.170
4592.454 -0.442 -0.427 4622.508 -0.693 -1.020
4595.376 -0.078 +0.120 4623.545 -0.542 -0.791
4596.398 +0.028 +0.234: 4624.546 -0.534 -0.542
4597.412 +0.149 +0.518 4625.473 -0.373 -0.376
4598.402 +0.256 +0.540 4627.548 -0.131 -0.014
4599.392 +0.241 +0.582 4628.538 -0.018 +0.284
4600.514 +0.252 +0.625 4629.546 +0.182 +0.389
4601.438 +0.080 +0.228 4636.583 -0.318: -0.531:
4602.422 -0.008 +0.020 4649.387 +0.250 +0.561
4604.402 -0.703 -0.945 4652.372 -0.044 -0.025
4605.336 -0.788 -1.138 4652.545 -0.096 -0.119
Observations in 1967
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9769.446 -0.395 0.626 2.07 9788.278 -0.145 1.075
9770.397 -0.293 0.796 2.38 9791.390 +0.216 1.473
9776.469 +0.319 1.651 3.53: 9795.247 +0.285 1.506
9777.379 +0.368 1.713 3.37 9796.262 +0.123 1.286
9782.481 -0.636 0.189 1.279 9799.281 -0.648 0.179 1.255
9783.402 -0.645 0.180 1.290 9814.271 -0.098 0.922 2.26:
9787.342 -0.253 0.904
Table 3 (cont.)
SZ Cygni
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3298.469 9.61 1.66 3772.407 9.54 1.52
3337.481 8.93 1.30: 3777.279 9.06 1.36
3437.263 9.83 1.79 3789.425 9.31 1.39
3483.295 9.81 1.73 3791.364 8.97 1.31:
3693.523 9.81 1.76 3795.367 9.36 1.59
3714.501 9.02 1.26 3803.270 9.56 1.52
3720.541 9.49 1.70: 4054.395 9.66 1.73
3722.537 9.69 1.73 4066.408 9.26 1.59
3743.518 9.55 1.37 4174.228 9.46: 1.68:
3763.438 9.19 1.59
TX Cygni
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3437.281 10.01 2.11 3800.271 9.49 2.11
3483.310 9.84 1.98 3803.330 9.90 2.15
3705.540 9.62 1.93 3830.329 9.55 2.12
3722.494 9.09 1.73 4049.446 9.39 1.98
3724.519 9.33 1.91 4054.441 10.00 2.08
3761.409 9.95 2.10 4100.437 9.86 2.03
3763.464 9.72 1.99 4111.417 9.77 2.17
3765.370 8.90 1.62 4147.322 9.44 1.73
3772.364 9.68 2.13 4150.282 9.19 1.77
3789.345 9.99 2.09 4162.362 9.06 1.60
3791.350 9.92 2.03 4166.293 9.34 1.90
3795.381 8.88: 1.71:
VX Cygni
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3693.470 10.41 1.94 3720.380 10.31 1.79
3703.534 9.58 1.43 3722.482 9.68 1.49
3705.521 9.73 1.59 3724.484 9.61 1.52
3714.468 10.47 1.97 3761.398 10.25 1.77
Table 3 (cont.)
(VX Cyg)
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3765.380 9.69 1.55 3803.344 9.61 1.46
3772.318 10.16 1.96: 3830.311 9.99 1.88
3777.289 10.54 2.02 4049.430 9.84 1.68
3788.487 9.90 1.74 4100.414 10.55 1.96
3789.358 9.95 1.86 4101.465 10.36 1.85
3791.336 10.09 1.92 4155.269 10.27 1.96
3800.261 10.33 1.75: 4203.229 10.30 1.81
BZ Cygni
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3437.246 10.12 1.56 3777.411 10.33 1.80
3647.502 10.53 1.67: 3788.472 10.50 1.72
3679.517 10.28 1.68 3795.336 10.06 1.65
3693.506 10.08 1.54 3803.254 10.09 1.56
3714.449 10.11 1.61 3868.223 10.32 1.70
3720.550 10.20 1.60: 4049.413 10.08 1.63
3722.467 10.06 1.63: 4050.451 10.22 1.71
3739.383 10.52 1.66 4100.460 10.15 1.70
3743.529 10.05 1.51: 4102.354 10.40 1.74:
3763.446 10.05 1.60 4113.345 10.49 1.76
3772.393 10.06 1.52
CD Cygni
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3630.489 8.68 1.31 1.03 3772.419 9.36 1.60 1.55
3705.500 9.45 1.68 1.46 3798.238 8.48 1.04 0.81
3714.428 8.57 1.21 1.00 3803.283 8.97 1.46 1.28
3720.524 9.21 1.58 1.53 3809.253 9.51 1.62 1.39
3724.561 9.54 1.63 3830.295 9.14 1.34 1.06
3743.497 9.27 1.40 4049.401 9.44 1.62
3761.300 9.23 1.46 1.18 4101.451 9.34 1.43 1.23
3763.423 8.41 0.99 0.65 4111.402 9.01 1.57 1.37:
Table 3 (cont.)
(CD Cyg)
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
4126.342 8.80 1.38 1.13 4155.253 8.58 1.07 0.79
4129.343 9.12 1.57 1.44 4159.330 8.67 1.32 1.07
4140.332 8.54 1.17
AA Geminorum
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3460.516 9.94 1.29 3789.580 9.97 1.24
3481.439 9.77 1.14 3793.590 9.47 0.92
3483.430 10.00 1.29 3928.405 9.69 1.02
3489.411 9.40 0.95 3931.412 9.49 1.03
3572.314 9.81 1.18 3957.343 9.89 1.26
3598.318 9.86: 1.16: 3966.301 9.59 1.12:
3599.352 9.76 1.09:
zeta Geminorum
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3481.505 3.65 0.71 0.51 3791.614 4.14 0.90 0.69
3483.492 3.87 0.84 0.68 3793.606 3.84 0.72 0.58
3489.463 3.80 0.73 0.51 3849.494 3.94 0.87 0.81
3572.329 3.67 0.68 0.49 3926.403 3.75 0.71 0.56
3598.336 4.16 0.90 0.87: 3928.420 3.68 0.67 0.56
3599.340 4.03 0.82 0.65 3935.345 3.85 0.77 0.55
3607.327 4.14 0.94 0.84 3957.331 3.70 0.69 0.57
3789.594 4.06 1.00 0.86 4203.461 3.76 0.82 0.75
Observations in 1967
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9776.554 0.140: 0.416: 0.863: 9796.536 0.164 0.444 0.873
9777.550 0.232 0.592 1.063 9810.591 0.627 1.120
9782.569 0.595 1.045 1.599 9814.631 0.376 0.745 1.197
9784.553 0.314 0.647 1.074 9825.138 0.314: 0.632: 1.104:
9786.551 0.169 0.444 0.875 9864.303 0.473 0.929 1.4
Table 3 (cont.)
AP Herculis
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3298.450 10.74 0.80 3749.425 10.50 0.62
3304.495 10.95 0.70 3753.289 10.94 0.84
3337.439 10.50 0.60 3761.278 10.52 0.62
3647.457 10.49 0.56 3772.269 10.62 0.69
3690.395 10.75 0.79 3777.256 11.13 0.93
3705.422 11.08 0.84 3789.294 10.95 0.71
3714.413 11.12: 0.82: 3791.228 10.43 0.65
3716.355 11.10 0.77: 3800.239 10.75 0.68
3720.355 10.56 0.66 4049.364 10.38 0.67
3722.436 11.01 0.80 4054.424 11.16: 0.81:
3724.448 11.13 0.89 4108.343 11.17 0.90
3730.319 10.54 0.64 4111.386 10.46 0.63
3732.433 10.87 0.81 4113.324 10.55 0.67
3739.325 10.46 0.59 4157.268 10.95 0.92
3743.308 10.96 0.88 4159.250 11.08 0.99
3747.320 11.03 0.78 4167.241 11.05 0.83
Z Lacertae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
2318.465 8.38 1.15 0.87 2728.302 8.24 1.00
2642.405 7.92 0.90 0.55 2738.355 8.37 1.08 0.66
2645.490 8.45 1.25 1.02 2756.331 8.73 1.33 1.14
2646.388 8.58 1.31 1.08 2770.213 8.50 1.15 0.79
2672.546 8.48 1.09 0.69: 3481.329 8.13 1.01 0.70
2675.429 8.05 0.95 0.61 3489.262 8.42 1.06 0.75
2676.452 8.21 1.06 0.74 3705.479 8.71 1.23 0.97
2685.497 7.92 0.81 0.62 3798.285 8.32 1.06 0.74:
2714.359 8.82 1.25 1.06 3878.274 8.80 1.38
2715.399 8.55 1.16 1.00: 3931.238 8.65 1.29 1.21
Observations in 1967
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9732.477 +0.051 +0.761 1.496 9759.390 -0.331 +0.319 0.941
Table 3 (cont.)
(Z Lac)
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9760.524 -0.152 +0.576 1.340 9769.513 -0.392 +0.175 0.755
9762.557 +0.192 +1.040 2.03 9789.356 -0.350 +0.111 0.687
9763.540 +0.295 +1.144 2.05 9790.469 -0.593 -0.114 0.355:
9766.562 -0.182: +0.432:
T Monocerotis
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3481.462 6.54 1.43 1.01 3789.632 5.85 1.31 0.84
3483.452 6.37 1.26 0.68 3791.624 6.01 1.39 0.96
3489.429 5.73 1.07 0.60 3793.636 6.11 1.42 1.07
3490.454 5.77 1.19 0.70 3849.484 6.23 1.45 1.17
3560.360 6.59 1.46 1.05 3935.280 6.50 1.53 1.23
3777.607 6.52: 1.45: 0.96: 4203.483 6.41 1.49 1.20
Observations in 1967
J.D.hel. DeltaV Deltab Deltau J.D.hel. DeltaV Deltab Deltau
2430000+ 2430000+
9784.630 -0.992 -0.255 0.512: 9808.546 -0.107 +0.958 2.21
9786.592 -0.973 -0.176 0.671 9810.544 -0.794 +0.027 0.865
9787.572 -0.869 -0.027 0.929 9812.572 -1.018 -0.260 0.500
9790.589 -0.688 +0.307 1.461 9814.603 -0.904 -0.024 0.833
9791.571 -0.622 +0.403 1.680 9825.564 -0.166 +0.956:
9796.522 -0.351 +0.837 2.50:
SV Monocerotis
J.D.hel. V B-V U-B J.D.hel. B-V U-B
2440000+ 2440000+
3481.486 8.41 1.36 0.98 3777.624 8.46 1.17 0.63
3483.473 8.67 1.40 1.12 3791.639 8.43 1.22 0.55
3489.444 7.66 0.81 0.37 3793.626 7.98 0.95 0.41
3490.436 7.70: 0.90: 0.32: 3928.280 8.61 1.21 0.58
3560.383 8.75 1.42 1.08 3935.267 8.04 1.14 0.69
3572.293 8.30 1.34 0.90 3957.274 8.78 1.42 1.06
3599.282 7.95 1.08 0.56 3966.282 8.14 1.16 0.67:
Table 3 (cont.)
(SV Mon)
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
4167.530 8.47 1.39 1.00 4251.370 7.69: 0.87: 0.23:
4203.511 8.41 1.14 0.51
SV Persei
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3438.569 8.49 0.91 3931.292 8.93 1.10
3490.506 9.35 1.14 3935.313 9.35 1.18
3560.338 8.85: 0.91: 3957.287 9.35 1.17
3599.298 9.14 1.24 4132.588 9.02 1.18
3607.281 8.76 1.08 4143.456 8.97 1.19
3789.529 9.23 1.27 4162.416 8.59 0.94
3791.542 9.22 1.14 4166.421 9.05 1.22
3830.385 8.85 1.08 4167.430 9.20 1.18
3837.477 9.03 1.05 4215.417 9.05 1.12
3878.297 9.23 1.26
VX Persei
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3438.488 9.61 1.44 0.91 3789.549 9.08 1.09 0.76:
3483.371 9.38 1.23 0.83 3873.343 9.69 1.39 1.03:
3489.378 9.31 1.31 1.03 3878.261 9.03 1.16 0.82
3490.405 9.45 1.38 1.04 3928.260 9.62 1.45 1.02
3560.303 9.20 1.17 0.84 4101.501 9.65 1.35 1.11
3572.275 9.08 1.15 0.85 4108.514 9.11 1.19 0.88
3737.505 8.99 1.12 0.83 4132.571 9.42 1.36 0.98
3739.413 9.29 1.19 0.97 4166.404 9.59 1.42 1.11:
SV Vulpeculae
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3298.489 7.75 1.72 3647.477 7.39 1.72 1.63
3304.462 7.64 1.61 1.48 3679.408 6.96 1.44 1.12
3337.457 7.51 1.71 1.64 3701.388 7.65 1.78 1.76
Table 3 (cont.)
(SV Vul)
J.D.hel. V B-V U-B J.D.hel. V B-V U-B
2440000+ 2440000+
3705.440 7.77 1.78 1.65 3772.293 7.07 1.54 1.31
3714.353 6.75 1.13 0.78 3781.299 7.33 1.73 1.62
3720.338 6.88 1.28 0.97 3789.318 7.58 1.78 1.63:
3722.452 6.92 1.37 1.06 3803.229 6.92 1.24 0.84
3732.449 7.22 1.64 1.55 4049.469 7.31 1.70 1.60
3739.354 7.40 1.77 1.65 4066.440 7.75 1.74 1.65
3753.280 7.68 1.75 1.58 4101.490 7.53 1.70
3761.269 6.75 1.15 0.88 4150.327 7.63 1.78 1.68
3763.415 6.78 1.24 0.94
THE LIGHT CURVES AND PERIOD CHANGES OF THE INDIVIDUAL VARIABLES
This section contains the light curves, the tables and the graphs of the O-C
values representing the period variation. Some remarks on the observed Cepheids are also
noted on the individual Cepheids. As in Papers I and II, it was not my intention to give
the full history of the variables which would have increased considerably the volume of
the paper. The variables were arranged according to the length of their period as in the
previous papers.
A detailed description of the construction of the O-C diagrams can be found in
Paper I (p. 32). The O-C values determined on the basis of visual, photographic and
photoelectric observations are marked with open circles, filled circles and triangles,
respectively. The size of these marks denotes the weight of the O-C values to be found in
the figures of this section.
The columns in the tables of the O-C residuals for each variable contain the
following data:
1. The moment of normal maximum (or that of median brightness)
2. The corresponding epoch
3. The O-C residual in days
4. The type of observation (vis for visual, pg for photographic and pe for photoelectric
observations)
5. The weight of the O-C residual depending on the type, number and quality of the observations.
6. The source of the observational data. When the name of the observer is not identical with
the name (or one of the names) given in the reference the observer's name is indicated in
the footnote to the table.
The determination of the O-C curves was by a weighted least squares fitting procedure.
The-O-C residuals with zero weight are not plotted in the diagrams, those with 0.5 weight
are plotted but were always omitted in the curve fitting procedure.
The formula by which the O-C residuals have been calculated is indicated at each
variable. These formulae usually refer to maximum light. If O-C diagrams for both maximum
and median brightnesses are presented, the two different calculated ephemerides are marked
with C_{max} and C_{med}, respectively.
BZ Cygni
The B light and the B-V colour curves of this small amplitude Cepheid are shown in
Fig. 2. The O-C residuals have been computed by the formula:
C = 2443774.037 + 10.141932d*E
Figure 2 B and B-V curves of BZ Cyg The period of this Cepheid has remained constant since the discovery of its light variation (see Fig. 3). The O-C value of the points with 0.5 weight is systematically smaller than that of Table 4 O-C residuals for BZ Cyg Obs.Max.J.D. E O-C Type w Reference 2418571.266 -2485 -0.070d pg 1 Furuhjelm (1921) 2423631.4 -1986 -0.8 pg 0.5 Rugemer (1933) 2425943.45 -1758 -1.07 pg 0.5 Beyer^1 (1934a) 2426673.97 -1686 -0.77 pg 0.5 Beyer^1 (1934a) 2426674.10 -1686 -0.64 pg 0.5 Lur'ye (1946) 2426826.18 -1671 -0.69 pg 0.5 Rugemer (1933) 2427161.806 -1638 +0.254 vis 1 Beyer (1934a) 2428043.35 -1551 -0.55 pg 0.5 Perova (1956) 2430649.47 -1294 -0.91 pg 0.5 Solov'yov (1945) 2431349.85 -1225 -0.32 pg 0.5 Perova (1956) 2433073.92 -1055 -0.38 pg 0.5 Perova (1956) 2433306.66 -1032 -0.90 pg 0.5 Perova (1956) 2433560.64 -1007 -0.47 pg 0.5 Perova (1956) 2433976.20 -966 -0.73 pg 0.5 Perova (1956) 2434159.608 -948 +0.123 pg 1 Nikulina (1970) 2436085.580 -758 -0.873 pg 0.5 Korovkina (1958) 2436441.64 -723 +0.22 pg 0 Korovkina (1959) 2436786.104 -689 -0.142 pe 3 Weaver et al. (1960) 2436796.408 -688 +0.020 pe 3 Oosterhoff (1960) 2437191.22 -649 -0.70 vis 0.5 Haussler (1965) 2437273.217 -641 +0.158 pe 1 Mitchell et al. (1964) 2437922.037 -577 -0.105 pg 1 Girnyak (1971) 2438986.726 -472 -0.319 pg 1 Girnyak (1971) 2443774.144 0 +0.107 pe 3 present paper Remark: 1 Observer: Plaut
Figure 3 O-C diagram of BZ Cyg the reliable points. This difference is caused by the fact that the phase of the normal maxima that are published without listing the original observational data is thought to be earlier than the phase of the true normal maximum determined from the photoelectric normal curve. SY Aurigae Its light and colour curves are plotted in Fig. 4. According to Janot Pacheco (1976) this variable has a faint blue companion.
Figure 4 B, B-V and U-B curves of SY Aur
The spectral classification of SY Aur (F5 III in the G.C.V.S - Kukarkin et al.,
1969-1970) may be in error since it suggests much lower luminosity than Cepheids with a
period of 10 days usually have.
The O-C residuals for this star have been obtained with the formulae:
C_{max} = 2443832.919 + 10.144698d*E
C_{med} = 2443830.379 + 10.144698d*E
for the maximum and median brightnesses, respectively. As can be seen in Fig. 5, the O-C
diagram can well be approximated by a parabola. The equation of the best fitting parabola is
as follows:
(O-C)_{par} = 1.73*10^{-7}*E^2
Table 5 O-C residuals for SY Aur
(maximum brightness)
Obs.Max.J.D. E O-C Type w Reference
2416504.146 -2694 +1.043d pg 1 Florya, Kukarkin (1931)
2418036.203 -2543 +1.251 vis 1 Enebo (1909)
2418776.770 -2470 +1.255 vis 1 Enebo (1911)
Table 5 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2419172.122 -2431 +0.964d pg 0.5 Robinson (1933)
2419800.992 -2369 +0.863 vis 1 Enebo (1914)
2421961.887 -2156 +0.937 pg 1 Jordan (1929)
2424071.542 -1948 +0.495 vis 1 Nielsen^1 (1928)
2425674.508 -1790 +0.598 p9 1 Rybka (1930)
2426212.158 -1737 +0.579 vis 1 Zakharov (1951)
2426221.88 -1736 +0.16 pg 0.5 Kiehl, Hopp (1977)
2426252.969 -1733 +0.812 vis 1 Kukarkin (1940)
2426759.901 -1683 +0.509 pg 1 Mashnauskas (1961)
2427368.30 -1623 +0.23 pg 0.5 Kiehl, Hopp (1977)
2427916.205 -1569 +0.317 vis 0.5 Nielsen^2 (1937b)
2428129.02 -1548 +0.09 pg 0.5 Fu De-Lian (1964)
2428586.053 -1503 +0.615 pg 1 Sokolov (1969)
2429245.098 -1438 +0.255 vis 0.5 Nielsen^2 (1941a)
2429265.733 -1436 +0.600 pg 1 Sokolov (1969)
2430695.700 -1295 +0.165 vis 0.5 Nielsen^2 (1952)
2432298.488 -1137 +0.091 vis 0.5 Nielsen^2 (1955)
2436214.295 -751 +0.044 pe 3 Bahner et al. (1977)
2436538.771 -719 -0.110 pg 1 Makarenko (1969)
2436833.104 -690 +0.027 pe 2 Oosterhoff (1960)
2436833.140 -690 +0.063 pe 3 Weaver et al. (1960)
2438293.771 -546 -0.143 pg 1 Makarenko (1969)
2439075.158 -469 +0.102 pe 2 Takase (1969)
2439348.913 -442 -0.049 pe 2 Wamsteker (1972)
2443832.981 0 +0.062 pe 3 present paper
Remarks: 1 Observer: Thorrud; 2 Observer: Arthur Nielsen
Table 6 O-C residuals for SY Aur
(median brightness)
Obs.Med.J.D. E O-C Type w Reference
2425671.922 -1790 +0.552d pg 1 Rybka (1930)
2436211.820 -751 +0.109 pe 3 Bahner et al. (1977)
2436830.664 -690 +0.127 pe 3 Weaver et al. (1960)
2443830.333 0 -0.046 pe 3 present paper
Figure 5 O-C diagram of SY Aur zeta Geminorum This star is one of the brightest Cepheids and is the prototype of the small amplitude Cepheids (see Fig. 6).
Figure 6 B, B-V and U-B curves of zeta Gem
Figure 7 O-C diagram of zeta Gem
The O-C residuals have been computed with the formulae:
C_{max} - 2443785.444 + 10.150135d*E
C_{med} - 2443782.743 + 10.150135d*E
for the maximum and median brightnesses, respectively. The O-C diagram in Fig. 7 shows a
continuous period decrease. The equation of the best fitting parabola is
(O-C)_{par} = -5.24d*10{-7}*E^2.
The deviations of the photoelectric and the reliable photographic O-C values from the above
parabola (for maximum brightness) are plotted in Fig. 8. Some systematic trend in these
deviations
Figure 8 Deviations from the mean O-C curve
can be seen. If the parabolic O-C diagram is interpreted as a result of the stellar
evolution, the small deviations from this parabola may be caused by the period noise. The
explanation of the Delta(O-C) values in terms of the light-time effect is not satisfactory
because the radial velocity measurements (Abt and Levy, 1974; Campbell, 1901 Evans, 1976;
Hase, 1929 Henroteau, 1925; Jacobsen, 1926; Scarfe, 1976) do not show any variation in the
average value of the radial velocity as would be expected in the case of the component in a
binary system. The only deviating average radial velocity value is that of Rufus (1932).
According to Abt and Levy (1974) the rate of the period decrease of zeta Gem is
four times greater than that predicted by the evolutionary calculations. Therefore they
suggested that the period variation was due to a light-time effect in a long period binary
(p_{orb} > 225 years) having a low mass secondary. Fernie and Turner (1978) remarked that the
closest star to the Cepheid might be a physical companion to zeta Gem. In this case they
must have an orbital period in excess of 10^6 years. In view of the above facts, there is
no unambiguous answer as to the binary nature of zeta Gem.
Table 7 O-C residuals for C Gem
(maximum brightness)
Obs.Max.J.D. E O-C Type w Reference
2394667.81 -4838 -11.28d vis 0.5 Argelander (1848)
2394677.33 -4837 -11.91 vis 0.5 Schmidt (1857)
2394982.19 -4807 -11.55 vis 0.5 Argelander (1848)
2395002.05 -4805 -11.99 vis 0.5 Schmidt (1857)
2395267.43 -4779 -10.52 vis 0.5 Argelander (1848)
2396027.855 -4704 -11.354 vis 1 Hagen^1 (1903)
2396077.93 -4699 -12.03 vis 0.5 Schmidt (1857)
2396088.465 -4698 -11.645 vis 1 Argelander (1869)
2396423.37 -4665 -11.69 vis 0.5 Schmidt (1857)
2396474.176 -4660 -11.639 vis 1 Argelander (1869)
2396565.026 -4651 -12.140 vis 1 Hagen^1 (1903)
2396818.76 -4626 -12.159 vis 0.5 Schmidt (1857)
2397154.525 -4593 -11.349 vis 1 Argelander (1869)
2397459.537 -4563 -10.841 vis 1 Hagen^1 (1903)
2397519.975 -4557 -11.304 vis 1 Argelander (1869)
2397875.456 -4522 -11.077 vis 1 Argelander (1869)
2398241.363 -4486 -10.575 vis 1 Argelander (1869)
2398536.305 -4457 -9.987 vis 1 Hagen^1 (1903)
2398586.501 -4452 -10.542 vis 1 Argelander (1869)
2398657.28 -4445 -10.81 vis 0.5 Schmidt (1857)
2398769.61 -4434 -10.13 vis 0.5 Nielsen^2 (1930b)
2398982.738 -4413 -10.160 vis 1 Argelander (1869)
2399022.66 -4409 -10.84 vis 0.5 Schmidt (1858)
2399317.451 -4380 -10.402 vis 1 Argelander (1869)
2399358.34 -4376 -10.11 vis 0.5 Schmidt (1858)
2399632.685 -4349 -9.822 vis 1 Zinner, Wachmann^3 (1931)
2399723.768 -4340 -10.090 vis 1 Argelander (1869)
2399744.06 -4338 -10.10 vis 0.5 Schmidt (1859)
2400099.937 -4303 -9.476 vis 1 Argelander (1869)
2400525.58 -4261 -10.14 vis 0.5 Schmidt (1861)
2400901.66 -4224 -9.61 vis 0.5 Schmidt (1861)
2401226.35 -4192 -9.73 vis 0.5 Schmidt (1863)
2401632.85 -4152 -9.23 vis 0.5 Schmidt (1864)
2401927.501 -4123 -8.936 vis 1 Argelander (1869)
2401998.52 -4116 -8.97 vis 0.5 Schmidt (1865)
2402313.385 -4085 -8.758 vis 1 Valentiner^4 (1900)
2402384.62 -4078 -8.57 vis 0.5 Schmidt (1866)
2402648.656 -4052 -8.441 vis 1 Valentiner^4 (1900)
2402719.98 -4045 -8.17 vis 0.5 Schmidt (1867)
2402993.591 -4018 -8.611 vis 1 Valentiner^4 (1900)
2403095.22 -4008 -8.48 vis 0.5 Schmidt (1868)
2403470.82 -3971 -8.44 vis 0.5 Schmidt (1869)
2403785.426 -3940 -8.486 vis 1 Valentiner^4 (1900)
2403786.076 -3940 -7.836 vis 0.5 Schmidt (1870)
2403786.543 -3940 -7.369 vis 1 Zinner, Wachmann^3 (1931)
2404090.631 -3910 -7.785 vis 1 Valentiner^4 (1900)
2404192.05 -3900 -7.87 vis 0.5 Schmidt (1871)
2404344.61 -3885 -7.56 vis 0.5 Guthnick^5 (1920)
2404466.252 -3873 -7.719 vis 1 Valentiner^4 (1900)
Table 7 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2404567.59 -3863 -7.88d vis 0.5 Schmidt (1872)
2404608.424 -3859 -7.649 vis 1 Zinner, Wachmann^3 (1931)
2404831.417 -3837 -7.959 vis 1 Valentiner^4 (1900)
2404932.84 -3827 -8.04 vis 0.5 Schmidt (1873)
2405166.882 -3804 -7.448 vis 1 Valentiner^4 (1900)
2405288.64 -3792 -7.49 vis 0.5 Schmidt (1874)
2405552.714 -3766 -7.322 vis 1 Valentiner^4 (1900)
2405603.46 -3761 -7.33 vis 0.5 Schmidt (1875)
2405928.082 -3729 -7.509 vis 1 Valentiner^4 (1900)
2406121.08 -3710 -7.36 vis 0.5 Schmidt (1876)
2406263.759 -3696 -6.786 vis 0.5 Belyavsky^6 (1910)
2406395.10 -3683 -7.40 vis 0.5 Schmidt (1877)
2406750.83 -3648 -6.92 vis 0.5 Schmidt (1878)
2407157.01 -3608 -6.75 vis 0.5 Schmidt (1879)
2407492.32 -3575 -6.39 vis 0.5 Schmidt (1880)
2407857.98 -3539 -6.14 vis 0.5 Schmidt (1881)
2408233.54 -3502 -6.13 vis 0.5 Schmidt (1882)
2408578.36 -3468 -6.42 vis 0.5 Schmidt (1883)
2408913.44 -3435 -6.29 vis 0.5 Schmidt (1884)
2409015.04 -3425 -6.19 vis 0.5 Nielsen^7 (1930b)
2410009.990 -3327 -5.955 vis 1 Hagen (1891)
2410354.144 -3293 -6.905 vis 0 Reed (1888)
2411360.45 -3194 -5.46 vis 0.5 Nielsen^7 (1930b)
2411908.99 -3140 -5.03 vis 0.5 Nielsen^8 (1930b)
2412851.996 -3047 -5.987 vis 0 Markwick (1892, 1894)
2413564.137 -2977 -4.355 vis 1 Plassmann (1900)
2413950.417 -2939 -3.780 vis 1 Plassmann (1900)
2413979.885 -2936 -4.763 vis 1 Pickering (1904)
2414316.42 -2903 -3.18 vis 0.5 Luizet (1902b)
2414335.691 -2901 -4.211 vis 1 Pickering (1904)
2414478.219 -2887 -3.785 vis 1 Plassmann (1900)
2414487.821 -2886 -4.333 pg 1 Wirtz (1901)
2414712.31 -2864 -3.15 vis 0.5 Luizet (1902b)
2415087.80 -2827 -3.21 vis 0.5 Luizet (1902b)
2415320.879 -2804 -3.586 vis 1 Plassmann (1900,1901,1908)
2415605.224 -2776 -3.445 vis 1 Tass (1925)
2415666.56 -2770 -3.01 vis 0.5 Luizet (1902b)
2415777.453 -2759 -3.769 vis 0.5 Yendell (1902b)
2415787.268 -2758 -4.104 vis 1 Plassmann (1908)
2415787.949 -2758 -3.423 vis 1 Nijland (1923)
2415797.704 -2757 -3.818 vis 1 Kopff (1902)
2415858.58 -2751 -3.84 vis 0.5 McDermott (1902)
2415970.085 -2740 -3.989 vis 1 Bilt (19261)
2416143.288 -2723 -3.338 vis 1 Plassmann (1908)
2416172.918 -2720 -4.159 vis 1 Lau (1904)
2416406.864 -2697 -3.666 vis 1 Götz (1906)
2416508.718 -2687 -3.313 vis 1 Plassmann (1908)
2416711.866 -2667 -3.168 vis 1 Olivier (1952)
2416721.611 -2666 -3.573 vis 1 Bilt (19261)
2416874.025 -2651 -3.411 vis 1 Tass^9 (1925)
2416874.320 -2651 -3.116 vis 1 Tass^10 (1925)
2416883.963 -2650 -3.623 vis 1 Plassmann (1908)
2416894.896 -2649 -2.840 vis 1 Schiller (1906)
2417228.908 -2616 -3.783 vis 1 Bilt (19261)
Table 7 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2417238.785 -2615 -4.056d vis 1 Plassmann (1908)
2417270.4 -2612 -2.9 vis 0.5 Furness^11 (1913b)
2417310.450 -2608 -3.442 vis 1 Lohnert (1909)
2417594.592 -2580 -3.504 vis 1 Olivier (1952)
2417604.986 -2579 -3.260 vis 1 Nijland (1923)
2417614.853 -2578 -3.543 vis 1 Bilt (1926a)
2417777.885 -2562 -2.913 vis 1 Plassmann (1908)
2417848.56 -2555 -3.29 vis 0.5 Nielsen^12 (1930b)
2417939.841 -2546 -3.359 vis 1 Nijland (1923)
2417950.165 -2545 -3.185 vis 1 Bilt (1926a)
2418315.716 -2509 -3.039 vis 1 Nijland (1923)
2418417.041 -2499 -3.216 vis 1 Mundler (1911a)
2418437.485 -2497 -3.072 vis 0.5 Scheller (1912)
2418559.427 -2485 -2.932 vis 1 Olivier (1952)
2418640.796 -2477 -2.764 vis 1 Nijland (1923)
2419250.821 -2417 -1.747 vis 0 Hornig (1915)
2419816.565 -2361 -4.410 vis 0 Breson (1913)
2419828.452 -2360 -2.673 vis 0.5 Hoffmeister (1916a)
2419899.406 -2353 -2.770 vis 1 Kaiser (1915)
2419939.979 -2349 -2.798 vis 0.5 Olivier (1952)
2420132.75 -2330 -2.879 vis 0.5 Nielsen^7 (1930b)
2420904.713 -2254 -2.327 vis 1 Luyten (1922)
2421127.79 -2232 -2.55 vis 0.5 Nielsen^13 (1930b)
2421320.897 -2213 -2.298 vis 1 Luyten (1922)
2422244.104 -2122 -2.754 vis 1 Rabe (1923)
2422315.70 -2115 -2.21 vis 0.5 Nielsen? (1930b)
2422366.187 -2110 -2.472 pe 3 Guthnick (1921)
2422375.973 -2109 -2.836 vis 1 Bellemin (1922)
2422721.639 -2075 -2.275 vis 1 Leiner (1922)
2422731.566 -2074 -2.498 vis 1 Rabe (1923)
2422732.368 -2074 -1.696 vis 1 Gallisot (1923)
2422803.383 -2067 -1.732 vis 1 Bellemin (1922)
2423056.382 -2042 -2.486 vis 1 Rabe (1923)
2423137.772 -2034 -2.297 vis 1 Nielsen^14 (1927a)
2423168.397 -2031 -2.123 vis 1 Zverev (1936)
2423269.793 -2021 -2.228 pe 3 Bottlinger (1928)
2423432.08 -2005 -2.34 vis 0.5 Nijland (1935)
2423442.428 -2004 -2.145 vis 1 Leiner (1928)
2423543.967 -1994 -2.108 vis 1 Parenago (1938)
2423736.995 -1975 -1.932 vis 1 Hopmann (1926)
2423797.392 -1969 -2.436 vis 1 Leiner (1928)
2424193.90 -1930 -1.78 vis 0.5 Nielsen^15 (1930b)
2424203.841 -1929 -1.993 vis 1 Leiner (1928)
2424529.05 -1897 -1.59 vis 0.5 Nijland (1935)
2424711.413 -1879 -1.927 vis 1 Leiner (1928)
2424761.751 -1874 -2.340 vis 1 Kukarkin (1940)
2425228.769 -1828 -2.228 pg 1 Hellerich (1935)
2425280.295 -1823 -1.453 vis 1 Leiner (1928)
2425310.362 -1820 -1.836 vis 1 Collmann (1930)
2425340.804 -1817 -1.845 pe 3 Gussow (1930)
2425411.71 -1810 -1.99 vis 0.5 Nijland (1935)
2425462.360 -1805 -2.090 vis 1 Kukarkin (1940)
2425625.169 -1789 -1.683 vis 1 Zverev (1936)
2426325.312 -1720 -1.900 vis 1 Zverev (1936)
Table 7 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2426802.918 -1673 -1.350d pe 3 Hall (1934)
2427056.638 -1648 -1.384 vis 1 Florya, Kukarkina (1953)
2427198.938 -1634 -1.185 vis 1 Nielsen^16 (1941b)
2428436.956 -1512 -1.484 p9 1 Gunther (1939)
2432883.249 -1074 -0.950 pe 3 Eggen (1951)
2432884.25 -1074 +0.05 vis 0 Ahnert (1949)
2432954.5 -1067 -0.7 vis 0.5 Pohl^17 (1951)
2434416.368 -923 -0.501 pe 3 Harris (1953)
2434609.43 -904 -0.29 vis 0.5 Marks^18 (1959)
2434711.76 -894 +0.54 vis 0 Marks (1959)
2435948.00 -772 -1.54 vis 0 Rudolph^19 (1960)
2436639.347 -704 -0.402 vis 1 Azarnova (1960)
2437004.583 -668 -0.571 vis 1 Mayall^20 (1964)
2437258.567 -643 -0.340 pe 1 Mitchell et al. (1964)
2437979.154 -572 -0.413 pe 2 Williams (1966)
2438527.582 -518 -0.092 pe 3 Wisniewski, Johnson (1968)
2439420.773 -430 -0.113 pe 3 Takase (1969)
2439765.870 -396 -0.121 pe 2 Sudzius (1969)
2439796.556 -393 +0.115 pe 3 present paper^21
2440984.10 -276 +0.09 vis 0.5 Braune et al.^22 (1972)
2441004.565 -274 +0.258 pe 2 Evans (1976)
2442111.17 -165 +0.50 vis 0.5 Busch^23 (1980)
2442354.51 -141 +0.235 pe 1 Scarfe^24 (1976)
2442465.897 -130 -0.029 pe 3 Depenchuk (1980)
2443217.388 -56 +0.352 vis 0.5 Busch^25 (1980)
2443258.14 -52 +0.50 vis 0.5 Braune et al.^26 (1978)
2443785.473 0 +0.029 pe 3 present paper
2443805.927 +2 +0.183 pe 2 Depenchuk (1980)
Remarks: (observers) 1 Heis; 2 Oudemans; 3 Winnecke; 4 Schonfeld;
5 Argelander; 6 Glasenapp; 7 Plassmann; 8 Knopf; 9 Terkan; 10 Fejes;
11 Whitney; 12 Luizet; 13 Vogelenzang; 14 Johansson; 15 Cecchini;
16 Loreta; 17 Handel; 18 Wroblewski; 19 Masuch; 20 Orchiston; 21 Abaffy;
22 Bischof; 23 Tietz; 24 Winzer; 25 Branzke; 26 Steinbach
Table 8 O-C residuals for zeta Gem
(median brightness)
Obs.Med.J.D. E O-C Type w Reference
2422363.426 -2110 -2.532d pe 3 Guthnick (1921)
2425338.134 -1817 -1.814 pe 3 Gussow (1930)
2426800.309 -1673 -1.258 pe 3 Hall (1934)
2434413.637 -923 -0.531 pe 3 Harris (1953)
2438524.912 -518 -0.061 pe 3 Wisniewski, Johnson (1968)
2439793.968 -393 +0.228 pe 3 present paper^1
2443782.611 0 -0.132 pe 3 present paper
Remark: 1 Observer: Abaffy
AN Aurigae
This variable has a faint companion within the edge of the diaphragm. The amplitude
of the light variation is smaller than that given by Schaltenbrand and Tammann (1971); this
is explainable by the effect of the visual companion (see Fig. 9). According to Madore (1977)
AN Aur has a B5 photometric companion.
Figure 9 B and B-V curves of AN Aur
Figure 10 O-C diagram of AN Aur The O-C residuals have been derived using the formula: C = 2443799.697 + 10.29056d*E The O-C diagram in Fig. 10 shows a constant period before J.D. 2437000. After this epoch the behaviour of the period is not known. The existence of a jump in the period followed by a rejump cannot be excluded since the shape of the light curve has changed compared with the photoelectric light curve of Weaver et al. (1960) observed at about J.D. 2437000. Earlier evidence for such a change in the light curve was the case of SU Cyg published in Paper I (p. 77). With AN Aur the ascending branch of the light curve became considerably shorter, the difference between the maximum and median brightnesses being about 0.4d smaller at J.D. 2443800 than about 7000 days earlier. A new series of photoelectric observations is urgently needed to prove or reject the existence of the rejump in AN Aur's period. Table 9 O-C residuals for AN Aur Obs.Max.J.D. E O-C Type w Reference 2417260.340 -2579 -0.003d pg 1 Parenago (1933) 2418742.05 -2435 -0.13 pg 0.5 Oosterhoff (1935) 2421262.44 -2190 -0.93 pg 0 Oosterhoff (1935) 2425513.34 -1777 -0.03 pg 0.5 Kukarkin (1932a) 2425524.18 -1776 +0.52 pg 0 Guthnick (1928) 2425729.72 -1756 +0.25 pg 0.5 Oosterhoff (1935) 2426181.91 -1712 -0.35 pg 0.5 Schneller (1932) 2426655.22 -1666 -0.40 pg 0.5 Oosterhoff (1935) 2429043.38 -1434 +0.35 pg 0.5 Frolov (1949) 2436832.907 -677 -0.081 pe 2 Oosterhoff (1960) 2436833.041 -677 +0.053 pe 3 Weaver et al. (1960) 2443799.026 0 -0.671 pe 3 present paper AP Herculis The light and colour curves of this Population II Cepheid are plotted in Fig. 11 (the observations made in 1977 are omitted
Figure 11 B and B-V curves of AP Her because of their phase difference). The existence of a blue photometric companion cannot be excluded (Madore, 1977). The O-C residuals have been computed with the formula: C = 2443745.347 + 10.4156d*E This is the Population II Cepheid showing the strongest period variations (see Fig. 12), the difference between the longest and the shortest values of the period being about 6 per cent of the
Figure 12 O-C diagram of AP Her period. There are several intervals when the value of the period cannot be determined with any certainty. The reliable periods are as follows: between J.D. 2415000 and J.D. 2419000 P = 10.400d between J.D. 2423700 and J.D. 2424700 P = 10.3970d between J.D. 2424700 and J.D. 2425300 P = 10.4260d between J.D. 2425800 and J.D. 2427000 P = 10.4338d between J.D. 2427000 and J.D. 2427400 P = 10.3945d between J.D. 2433000 and J.D. 2433850 P = 10.4277d between J.D. 2433850 and J.D. 2434850 P = 10.3898d between J.D. 2434850 and J.D. 2435600 P = 10.4209d between J.D. 2435600 and J.D. 2437200 P = 10.3715d between J.D. 2437200 and J.D. 2443800 P = 10.4156d but three observations made in 1977 show that the period in that year might have been smaller than reported here. Bogdanov (1973) found the period variation to be periodic with P = 8840d. Several pronounced cycles can be seen in Fig. 1; but the period variation is not periodic at all. Nevertheless, AP Her deserves to be subjected to regular photoelectric monitoring because of its extremely strong period changes. Table 10 O-C residuals for AP Her Obs.Max.J.D. E O-C Type w Reference 2415163.011 -2746 +18.902dpg 1 Parenago^1 (1951) 2418959.142 -2381 +13.339 pg 1 Parenago^1 (1951) 2422855.43 -2007 +14.19 pg 0.5 Oosterhoff (1935) 2423168.32 -1977 +14.61 pg 0.5 Oosterhoff (1935) 2423720.50 -1924 +14.77 pg 0.5 Oosterhoff (1935) 2423730.408 -1923 +14.260 pg 1 Bohlin (1925) 2423959.22 -1901 +13.93 pg 0.5 Oosterhoff (1935) 2424084.156 -1889 +13.877 vis 1 Bohlin (1925) 2424104.992 -1887 +13.882 vis 0.5 Beyer (1926) 2424302.443 -1868 +13.437 vis 1 Beyer (1926) 2424333.70 -1865 +13.45 pg 0.5 Oosterhoff (1935) 2424349.164 -1864 +18.495 vis 0 Zakharov (1954b) 2424427.2 -1856 +13.2 pg 0.5 Tsessevich (1950) 2424447.842 -1854 +13.017 vis 1 Beyer (1926, 1928) 2424686.987 -1831 +12.604 vis 1 Beyer (1928) 2424780.73 -1822 +12.61 pg 0.5 Oosterhoff (1935) 2424801.735 -1820 +12.780 vis 1 Beyer (1928) 2425020.63 -1799 +12.95 pg 0.5 Oosterhoff (1935) 2425083.292 -1793 +13.116 vis 1 Beyer (1928) 2425155.52 -1786 +12.43 pg 0.5 Oosterhoff (1935) 2425197.832 -1782 +13.084 vis 1 Beyer (1928) 2425426.194 -1760 +12.303 vis 1 Beyer (1934b) 2425447.687 -1758 +12.965 vis 1 Zakharov (1954b) 2425509.3 -1752 +12.1 pg 0.5 Tsessevich (1950) 2425520.605 -1751 +12.974 vis 1 Beyer (1934b) 2425530.50 -1750 +12.45 pg 0.5 Oosterhoff (1935) 2425791.87 -1725 +13.43 pg 0.5 Huth (1965) 2425800.74 -1724 +11.89 pg 0.5 Oosterhoff (1935) 2425853.026 -1719 +12.095 vis 1 Beyer (1934b) 2426113.47 -1694 +12.15 pg 0.5 Huth (1965) 2426238.53 -1682 +12.22 pg 0.5 Oosterhoff (1935) 2426300.945 -1676 +12.144 vis 1 Beyer (1934b) 2426500.54 -1657 +13.84 pg 0.5 Huth (1965) 2426614.184 -1646 +12.915 vis 1 Beyer (1934b) 2426771.73 -1631 +14.23 pg 0.5 Huth (1965) 2426842.79 -1624 +12.38 pg 0.5 Oosterhoff (1935) 2426907.02 -1618 +14.11 pg 0.5 Tsessevich (1950) 2426927.611 -1616 +13.874 vis 1 Florya, Kukarkina (1953) 2426979.672 -1611 +13.857 vis 1 Beyer (1934b) 2427197.79 -1590 +13.25 pg 0.5 Oosterhoff (1935) 2427229.193 -1587 +13.403 vis 1 Beyer (1934b) 2427291.412 -1581 +13.129 vis 1 Florya, Kukarkina (1953) 2427312.11 -1579 +13.00 pg 0.5 Huth (1965) 2427353.818 -1575 +13.041 vis 1 Beyer (1934b) 2427601.60 -1551 +10.85 pg 0.5 Huth (1965) 2427634.15 -1548 +12.15 pg 0.5 Tsessevich (1950) 2427932.71 -1520 +19.08 pg 0 Huth (1965) 2428367.02 -1478 +15.93 pg 0.5 Huth (1965) 2428752.24 -1441 +15.77 pg 0.5 Huth (1965) Table 10 (cont.) Obs.Max.J.D. E O-C Type w Reference 2429156.51 -1402 +13.83d pg 0.5 Huth (1965) 2429541.12 -1365 +13.07 pg 0.5 Huth (1965) 2429562.000 -1363 +13.116 pg 1 Parenago^1 (1951) 2429812.230 -1339 +13.371 pg 1 Kapko (1949) 2430133.254 -1308 +11.512 pg 0.5 Kapko (1949) 2433118.570 -1021 +7.551 pg 1 Kapko (1951) 2433149.97 -1018 +7.70 pg 0.5 Vasil'yan. et al^2 (1970) 2433379.06 -996 +7.65 pg 0.5 Vasil'yan. et al^2 (1970) 2433483.485 -986 +7.920 pg 1 Kapko (1951) 2433556.53 -979 +8.06 pg 0.5 Huth (1965) 2433827.49 -953 +8.21 pg 0.5 Huth (1965) 2433859.047 -950 +8.520 pvis 1 Koval' (1955) 2433869.18 -949 +8.24 pg 0.5 Vasil'yan. et al.^2 (1970) 2433879.676 -948 +8.318 pg 1 Kapko (1952) 2434201.85 -917 +7.61 pg 0.5 Vasil'yan. et al.^2 (1970) 2434211.63 -916 +6.97 pg 0.5 Huth (1965) 2434232.747 -914 +7.258 pg 1 Koval' (1955) 2434253.698 -912 +7.378 pg 1 Kapko (1964) 2434575.472 -881 +6.269 pg 1 Koval' (1955) 2434596.10 -879 +6.07 pg 0.5 Vasil'yan. et al.^2 (1970) 2434606.852 -878 +6.402 pg 1 Kapko (1964) 2434607.09 -878 +6.64 pg 0.5 Huth (1965) 2434950.62 -845 +6.46 pg 0.5 Vasil'yan. et al.' (1970) 2434970.851 -843 +5.855 pg 1 Kapko (1964) 2435012.30 -839 +5.64 pg 0.5 Huth (1965) 2435335.87 -808 +8.35 pg 0.5 Huth (1965) 2435356.852 -806 +6.479 pg 1 Kapko (1964) 2435387.84 -803 +6.22 pg 0.5 Vasil'yan. et al.^2 (1970) 2435626.97 -780 +5.79 pg 0.5 Huth (1965) 2435627.283 -780 +6.104 pe 2 Walraven et al. (1958) 2435690.023 -774 +6.350 p9 1 Kapko (1964) 2435700.43 -773 +6.34 pg 0.5 Vasil'yan. et al.^2 (1970) 2435938.70 -750 +5.05 pg 0.5 Huth (1965) 2436041.959 -740 +4.156 pg 1 Kapko (1964) 2436063.39 -738 +4.76 pg 0.5 Vasil'yan. et al.^2 (1970) 2436395.029 -706 +3.096 pg 1 Kapko (1964) 2436426.34 -703 +3.16 pg 0.5 Vasil'yan. et al.^2 (1970) 2436457.68 -700 +3.25 pg 0.5 Huth (1965) 2436778.772 -669 +1.461 p9 1 Kapko (1964) 2436789.29 -668 +1.56 pg 0.5 Vasil'yan. et al.^2 (1970) 2436799.287 -667 +1.145 pe 3 Weaver et al. (1960) 2436810.19 -666 +1.63 pg 0.5 Huth (1965) 2437028.62 -645 +1.34 pg 0.5 Huth (1965) 2437131.843 -635 +0.402 pg 1 Kapko (1964) 2437163.54 -632 +0.85 pg 0.5 Vasil'yan. et al.^2 (1970) 2437402.87 -609 +0.62 pg 0.5 Huth (1965) 2437527.274 -597 +0.040 pg 1 Kapko (1964) 2437578.98 -592 -0.33 pg 0.5 Vasil'yan. et al.^2 (1970) 2437818.73 -569 -0.14 pg 0.5 Huth (1965) 2437829.23 -568 -0.06 pg 0.5 Vasil'yan. et al.^2 (1970) 2437829.325 -568 +0.039 pe 2 Michalowska-Smak, Smak (1965) 2437860.538 -565 +0.005 pg 1 Kapko (1964) 2437871.009 -564 +0.060 pe 2 Williams (1966) Table 10 (cont.) Obs.Max.J.D. E O-C Type w Reference 2438224.72 -530 -0.36d pg 0.5 Huth (1965) 2438225.026 -530 -0.053 pe 3 Kwee and Braun (1967) 2438245.76 -528 -0.15 pg 0.5 Vasil'yan et al.^2 (1970) 2438287.402 -524 -0.171 pg 1 Kapko (1964) 2438463.64 -507 -1.00 pg 0.5 Huth (1965) 2438578.06 -496 -1.15 pg 0.5 Vasil'yan. et al. (1970) 2439598.85 -398 -1.09 pg 0.5 Vasil'yan. et al. (1970) 2443745.357 0 +0.010 pe 3 present paper Remarks: 1 Observer: Fedorovich; 2 Obs.: Pahomova Z Lacertae The light and colour curves of Z Lac are shown in Fig. 13.
Figure 13 B, B-V and U-B curves of Z Lac
The O-C residuals have been computed using the ephemeris:
C = 2442827.123 + 10.885613d*E
The O-C diagram in Fig. 14 shows a continuous decrease of the period. The equation of the
fitted parabola is:
(O-C)_{par} = -3.4d*10^{-8}*E^2
Figure 14 O-C diagram of Z Lac Table 11 O-C residuals for Z Lac Obs.Max.J.D. E O-C Type w Reference 2417931.642 -2287 -0.084d vis 1 Enebo (1908) 2418334.276 -2250 -0.218 vis 1 Enebo (1909) 2418475.781 -2237 -0.226 pg 0.5 Robinson (1933) 2418541.107 -2231 -0.213 vis 1 Bilt (1926b) 2419009.285 -2188 -0.117 vis 1 Enebo (1912) 2419368.365 -2155 -0.262 vis 1 Bilt (1926b) 2420108.601 -2087 -0.248 pg 1 Hertzsprung (1922) 2420239.373 -2075 -0.103 vis 1 Bilt (1926b) 2421534.721 -1956 -0.143 pg 1 Hertzsprung (1922) 2424528.5 -1681 +0.1 vis 0.5 Selivanov (1929) 2425747.37 -1569 -0.23 pg 0.5 Kiehl, Hopp (1977) 2425834.646 -1561 -0.035 vis 1 Parenago (1938) 2425845.565 -1560 -0.002 vis 1 Beyer (1934b) 2426313.568 -1517 -0.080 vis 1 Terkan (1935) 2426542.105 -1496 -0.141 pg 1 Zonn (1933) 2426542.171 -1496 -0.075 vis 1 Kukarkin (1940) 2426618.132 -1489 -0.313 vis 1 Beyer (1934b) 2426760.019 -1476 +0.061 vis 0.5 Dziewulski et al. (1946) 2426803.371 -1472 -0.130 vis 0.5 Dziewulski et al. (1946) 2426879.52 -1465 -0.18 pg 0.5 Kiehl, Hopp (1977) 2427108.157 -1444 -0.141 pg 1 Zonn (1933) 2427293.293 -1427 -0.060 vis 1 Florya, Kukarkina (1953) 2428229.624 -1341 +0.108 pg 1 Gur'yev (1937) 2428283.881 -1336 -0.063 vis 0.5 Dziewulski (1947) 2428349.260 -1330 +0.002 pg 0.5 Dziewulski et al. (1946) 2428458.01 -1320 -0.10 pg 0.5 Fu De-Lian (1964) 2428556.071 -1311 -0.013 pg 0.5 Dziewulski et al. (1946) 2428741.160 -1294 +0.020 pg 1 Gur'yev (1938) 2429046.02 -1266 +0.08 pg 0.5 Katz (1946) 2433084.478 -895 -0.021 pe 3 Eggen (1951) 2433519.846 -855 -0.078 pg 1 Solov'yov (1952) 2434575.782 -758 -0.046 pg 1 Chuprina (1954) 2434967.738 -722 +0.028 pg 1 Chuprina (1956) 2435751.452 -650 -0.023 pe 3 Bahner et al. (1971) Table 11 (cont.) Obs.Max.J.D. E O-C Type w Reference 2436230.385 -606 -01057 pe 3 Bahner et al. (1971) 2436829.095 -551 -0.055 pe 3 Bahner et al. (1962) 2437199.191 -517 -0.070 pe 3 Mitchell et al. (1964) 2437928.575 -450 -0.022 pg 1 Girnyak (1964) 2439180.423 -335 -0.020 pe 3 Takase (1969) 2439768.312 -281 +0.046 pe 2 present paper^1 2440083.936 -252 -0.013 pe 3 Asteriadis et al. (1977) 2440791.548 -187 +0.035 pe 3 Asteriadis et al. (1977) 2442827.154 0 +0.031 pe 3 present paper Remark: 1 Observer: Abaffy VX Persei The light and colour curves of this neglected Cepheid variable are plotted in Fig. 15. VX Per is situated in the region of
Figure 15 B, B-V and U-B curves of VX Per the h and X Per double cluster (Kukarkin et al., 1976). The O-C residuals have been calculated with the formula: C = 2443758.994 + 10.88904d*E The O-C diagram in Fig. 16 shows one change in the period, but both the time of the change and the values of the period are uncertain.
Figure 16 O-C diagram of VX Per Table 12 O-C residuals for VX Per Obs.Max.J.D. E O-C Type w Reference 2418229.008 -2344 -6.076d vis 1 Pracka (1912) 2420363.01 -2148 -6.33 vis 0.5 Hoffmeister (1916b) 2420438.854 -2141 -6.705 pg 0.5 Robinson (1933) 2431279.215 -1146 -0.939 pg 0.5 Solov'yov (1955) 2436811.804 -638 +0.018 pe 3 Oosterhoff (1960) 2436822.654 -637 -0.022 pe 3 Weaver et al. (1960) 2436899.368 -630 +0.469 pg 0.5 Mauder (1960) 2443758.994 0 0.000 pe 3 present paper SV Persei
Figure 17 B and B-V curves of SV Per The light and colour curves of SV Per are plotted in Fig. 17. According to Madore (1977) this Cepheid has a B2 photometric companion. The O-C residuals have been calculated using the formula: C = 2443839.296 + 11.129318d*E The O-C diagram in Fig. 18 shows a rejumping period, the sudden changes in the period (jump and rejump) occurred at about J.D. 2426300. The values of the period are as follows: before J.D. 2426300 P = 11.129289d after J.D. 2426300 P = 11.129318d Although the rejumping period seems to be the proper interpretation of the O-C diagram, another possibility cannot be excluded, viz. a sinusoidal wave caused by the light-time effect in the binary system. In this latter case the average period would be P = 11.128986d in the course of the last 70 years.
Figure 18 O-C diagram of SV Per Table 13 O-C residuals for SV Per Obs.Max.J.D. E O-C Type w Reference 2417930.893 -2328 +0.649d vis 1 Enebo (1908) 2418298.108 -2295 +0.597 vis 1 Enebo (1909) 2418977.140 -2234 +0.740 vis 1 Enebo (1914) 2419611.313 -2177 +0.542 pg 0.5 Robinson (1933) 2420112.339 -2132 +0.749 vis 1 Enebo (1914) 2424953.506 -1697 +0.663 vis 0.5 Mergentaler^1 (1948) 2425955.263 -1607 +0.781 vis 0.5 Mergentaler^2 (1948) 2426210.883 -1584 +0.427 vis 0.5 Zakharov (1953) 2426288.996 -1577 +0.634 vis 1 Kukarkin (1940) 2426377.692 -1569 +0.296 pg 1 Rugemer (1932) 2426623.44 -1547 +1.20 vis 0 Mergentaler^3 (1948) 2427401.925 -1477 +0.632 vis 0.5 Mergentaler^4 (1948) 2430027.889 -1241 +0.077 pg 1 Mergentaler (1948) 2433232.980 -953 -0.076 pe 2 Eggen et al. (1957) 2434000.04 -884 -0.94 pg 0 Fu De-Lian (1964) 2435848.470 -718 +0.024 pe 3 Bahner et al (1977) 2436260.245 -681 +0.015 pe 3 Bahner et al. (1977) 2437595.773 -561 +0.024 pe 2 Mitchell et al. (1964) Table 13 (cont.) Obs.Max.J.D. E O-C Type w Reference 2439075.985 -428 +0.037 pe 3 Takase (1969) 2439209.541 -416 +0.041 pe 3 Wamsteker (1972) 2441913.906 -173 -0.018 pe 3 Vasil'yanovskaya (1977) 2443839.246 0 -0.050 pe 3 present paper Remarks: 1 Observer: Grouiller; 2 Obs.: Grouiller and Bloch 3 Obs.: Rybka; 4 Obs.: Chang Yuin AA Geminorum This variable has two faint companions within the edge of the diaphragm. The light and colour curves in Fig. 19 are not complete since the weather conditions did not permit the coverage of the light curve at the other phases.
Figure 19 B and B-V curves of AA Gem
Figure 20 O-C diagram of AA Gem The O-C residuals have been computed by the formula: C = 2443737.633 + 11.302328d*E The period of the light variation has been constant since its discovery (see Fig. 20). Table 14 O-C residuals for AA Gem Obs.Max.J.D. E O-C Type w Reference 2420726.34 -2036 +0.25d pg 0.5 Kukarkin (1930) 2425133.785 -1646 -0.216 pg 1 Prager (1929) 2425348.970 -1627 +0.225 vis 1 Kukarkin (1940) 2426015.515 -1568 -0.068 vis 1 Beyer (1934a) 2427055.602 -1476 +0.205 vis 1 Beyer (1934a) 2428061.251 -1387 -0.053 vis 1 Martynov (1951) 2428683.197 -1332 +0.265 vis 1 Martynov (1951) 2428953.877 -1308 -0.311 pg 1 Koshkina (1963) 2429157.579 -1290 -0.051 pg 1 Chudovicheva (1952) 2429439.991 -1265 -0.197 vis 1 Martynov (1951) 2429530.500 -1257 -0.107 pg 1 Koshkina (1963) 2430118.358 -1205 +0.030 vis 1 Martynov (1951) 2430785.592 -1146 +0.427 vis 1 Martynov (1951) 2431135.468 -1115 -0.069 pg 1 Chudovicheva (1952) 2432446.439 -999 -0.168 pg 1 Chudovicheva (1952) 2433543.332 -902 +0.399 pg 1 Chudovicheva (1952) 2433599.199 -897 -0.246 pg 1 Satyvaldiev (1970) 2433972.437 -864 +0.015 pg 1 Rosino, Nobili (1955) 2434029.050 -859 +0.117 pg 1 Koshkina (1963) 2434537.701 -814 +0.163 pg 1 Rosino, Nobili (1955) 2436504.096 -640 -0.047 pg 1 Satyvaldiev (1970) 2436831.705 -611 -0.206 pe 2 Weaver et al. (1960) 2437566.83 -546 +0.27 pg 0.5 Ahnert (1962) 2437634.342 -540 -0.034 pe 2 Mitchell et al. (1964) 2438436.673 -469 -0.168 pg 1 Satyvaldiev (1970) 2439250.725 -397 +0.116 pe 2 Takase (1969) 2443737.679 0 +0.046 pe 2 present paper RX Aurigae The light and colour curves of RX Aur are plotted in Fig. 21. According to the G.C.V.S. (Kukarkin et al., 1969-1970) the spectral type of this Cepheid is G0 III. Apart from the variation in Table 15 O-C residuals for RX Aur Obs.Max.J.D. E O-C Type w Reference 2415816.313 -2410 -0.867d pg 1 Williams (1906) 2416222.77 -2375 -1.23 pg 0.5 Kukarkin^1 (1931) 2417338.90 -2279 -0.96 vis 0.5 Williams (1906, 1907) 2417478.47 -2267 -0.88 vis 0.5 Muller, Hartwig (1918-1920) 2417675.843 -2250 -1.103 vis 1 Zeipel (1908) 2419698.601 -2076 -0.840 pg 0.5 Robinson (1933) 2421883.742 -1888 -0.924 pg 1 Jordan (1929) 2425115.469 -1610 -0.540 vis 0.5 Dziewulski et al.^2 (1946) 2425243.007 -1599 -0.861 pg 1 Hellerich (1935) 2425592.584 -1569 +0.010 vis 0 Parenago (1938) 2425650.202 -1564 -0.490 vis 1 Kukarkin (1931) 2426219.80 -1515 -0.44 pg 0.5 Kiehl, Hopp (1977) Table 15 (cont.) Obs.Max.J.D. E O-C Type w Reference 2426219.952 -1515 -0.293d vis 0.5 Zakharov (1951) 2426405.567 -1499 -0.655 vis 1 Terkan (1935) 2426452.003 -1495 -0.713 pg 1 Iwanowska et al. (1932) 2426498.823 -1491 -0.387 vis 1 Zverev (1936) 2426568.123 -1485 -0.829 vis 0.5 Iwanowska et al. (1932) 2426673.385 -1476 -0.178 vis 1 Kukarkin (1940) 2426905.458 -1456 -0.576 vis 0.5 Dziewulski et al. (1946) 2426997.79 -1448 -1.23 pg 0 Kiehl, Hopp (1977) 2427707.442 -1387 -0.616 vis 0.5 Dziewulski et al. (1946) 2428370.107 -1330 -0.493 pg 0.5 Dziewulski et al. (1946) 2428416.608 -1326 -0.486 pg 0.5 Dziewulski et al. (1946) 2428881.32 -1286 -0.71 pg 0.5 Karimova^3 (1949) 2430043.972 -1186 -0.417 pg 1 Mergentaler (1948) 2433287.54 -907 +0.18 vis 0.5 Pohl^4 (1951) 2433461.739 -892 +0.030 pe 2 Eggen et al. (1957) 2433982.06 -847 -2.71 pg 0 Fu De-Lian (1964) 2436228.158 -654 +0.047 pe 3 Bahner et al. (1977) 2436542.00 -627 +0.054 pg 0.5 Kiehl, Hopp (1977) 2437611.298 -535 -0.014 pe 3 Mitchell et al. (1964) 2437936.922 -507 +0.151 pe 1 Williams (1966) 2439064.203 -410 -0.051 pe 3 Takase (1969) 2439494.226 -373 -0.099 pe 3 Wamsteker (1972) 2441005.307 -243 -0.078 pe 2 Evans (1976) 2442365.266 -126 -0.072 vis 0.5 Berdnikov (1977) 2443515.872 -27 -0.197 vis 0.5 Busch^5 (1980) 2443829.995 0 +0.091 pe 3 present paper Remarks: 1 Observer: Blazhko; 2 Obs.: Rybka; 3 Obs.: Ishchenko; 4 Obs.: Mielke; 5 Obs.: Branzke
Figure 21 B, B-V and U-B curves of RX Aur the spectral type during a pulsation cycle, the III luminosity class is not typical for a Cepheid variable. The O-C residuals have been calculated with the formula: C = 2443829.904 + 11.623537d*E The O-C diagram in Fig. 22 shows one change in the period: before J.D. 2434900 P = 11.624230d after J.D. 2434900 P = 11.623537d
Figure 22 O-C diagram of RX Aur RY Cassiopeiae
Figure 23 B and B-V curves of RY Cas
The light and colour curves in Fig. 23 show some minor changes in the shape of the
light curve in comparison with the earlier photoelectric light curves.
The O-C residuals have been derived using the formula:
C = 2443826.530 + 12.138888d*E
The period of RY Cas is continuously increasing (see Fig. 24), the approximate parabola
being:
(O-C)_{par} = 5.31d*10^{-7}*E^2
Figure 24 O-C diagram of RY Cas
Table 16 O-C residuals for RY Cas
Obs.Max.J.D. E O-C Type w Reference
2416637.920 -2240 +2.494d pg 1 Kukarkin^1 (1940)
2417284.5 -2187 +5.7 vis 0 Duner et al. (1906)
2417536.9 -2166 +3.2 vis 0 Ichinohe (1907)
2417633.346 -2158 +2.536 vis 1 Graff (1921b)
2417694.384 -2153 +2.880 vis 0.5 Pracka (1910)
2417839.703 -2141 +2.532 vis 1 Luizet (1908b)
2419672.345 -1990 +2.202 vis 1 Graff (1921b)
2422451.620 -1761 +1.672 vis 0.5 Graff (1921b)
2424041.467 -1630 +1.324 pg 1 Kukarkin (1940)
2425485.97 -1511 +1.30 vis 0.5 Nielsen^2 (1955)
2426165.68 -1455 +1.23 pg 0.5 Kiehl, Hopp (1977)
2426699.636 -1411 +1.077 vis 1 Kukarkin (1940)
2429017.82 -1220 +0.73 pg 0.5 Pevunova (1940)
2430547.208 -1094 +0.621 p9 1 Solov'yov (1954)
2431251.473 -1036 +0.831 pg 1 Solov'yov (1954)
2432732.134 -914 +0.548 pg 1 Solov'yov (1954)
2433423.88 -857 +0.38 vis 0.5 Nielsen^3 (1955)
2433472.434 -853 +0.375 p9 1 Solov'yov (1954)
2435291.32 -703 -1.57 p9 0 Parenago^4 (1956)
2435438.63 -691 +0.07 pg 0.5 Romano (1959)
2435875.84 -655 +0.28 pg 1 Zonn, Semeniuk (1959)
2436798.286 -579 +0.172 pe 3 Weaver et al. (1960)
2436810.350 -578 +0.097 pe 3 Oosterhoff (1960)
2436871.012 -573 +0.065 pe 3 Bahner et al. (1962)
Table 16 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2437016.475 -561 -0.139 vis 0.5 Sachse (1973)
2437939.164 -485 -0.005 pe 1 Williams (1966)
2439055.344 -393 -0.783 vis 0 Sachse (1973)
2439444.331 -361 -0.060 vis 0.5 Sachse (1973)
2442066.14 -145 -0.25 vis 0.5 Small (1974)
2443826.585 0 +0.055 pe 3 present paper
Remarks: 1 Observers: Blazhko and Parenago; s Obs.: Brunt
3 Obs.: Petersen 4 Obs.: Zhdanova
SZ Cassiopeiae
The light and colour curves of this small amplitude Cepheid can be seen in Fig. 25.
SZ Cas is situated in the corona of the double cluster h and x Per (Efremov, 1964).
The O-C residuals have been computed with the ephemeris:
C = 2443818.142 + 13.637747d*E
The period of SZ Cas is continuously increasing (see Fig. 26). The least squares fitting
procedure has resulted in the parabola:
(O-C)_{par} = 1.01d*10^{-5}*E^2
Figure 25 B and B-V curves of SZ Cas Table 17 O-C residuals for SZ Cas Obs.Max.J.D. E O-C Type w Reference 2415753.8 -2061 +43.1d pg 0.5 Gerasimovic (1927b) 2416039.2 -2036 +42.1 pg 0.5 Gerasimovic (1927b) 2416338.4 -2016 +41.2 pg 0.5 Gerasimovic (1927b) 2416678.7 -1993 +40.6 pg 0.5 Gerasimovic (1927b) 2416738.046 -1989 +45.383 pg 0 Kukarkin (1932c) 2417085.8 -1963 +38.6 pg 0.5 Gerasimovic (1927b) 2417220.442 -1953 +36.820 vis 0.5 Pracka (1910) Table 17 (cont.) Obs.Max.J.D. E O-C Type w Reference 2417480.8 -1934 +38.1d pg 0.5 Gerasimovic (1927b) 2417833.6 -1908 +36.3 pg 0.5 Gerasimovic (1927b) 2418542.5 -1856 +36.0 pg 0.5 Gerasimovic (1927b) 2419017.2 -1821 +33.4 pg 0.5 Gerasimovic (1927b) 2419030.229 -1820 +32.787 vis 0.5 Mundler (1911b, 1919) 2419805.7 -1763 +30.9 pg 0.5 Gerasimovic (1927b) 2420581.0 -1706 +28.9 pg 0.5 Gerasimovic (1927b) 2420718.996 -1696 +30.473 pg 0.5 Robinson (1933) 2420814.397 -1689 +30.410 vis 0.5 Zinner^1 (1932) 2420839.8 -1687 +28.5 pg 0.5 Gerasimovic (1927b) 2421084.6 -1669 +27.9 pg 0.5 Gerasimovic (1927b) 2421248.225 -1657 +27.830 vis 0.5 Zinner^1 (1932) 2421261.961 -1656 +27.928 vis 0.5 Luizet (1923) 2421479.3 -1640 +27.1 pg 0.5 Gerasimovic (1927b) 2421969.959 -1604 +26.763 vis 0.5 Zinner^1 (1932) 2422323.3 -1578 +25.5 pg 0.5 Gerasimovic (1927b) 2422582.0 -1559 +25.1 pg 0.5 Gerasimovic (1927b) 2422935.7 -1533 +24.2 pg 0.5 Gerasimovic (1927b) 2423439.4 -1496 +23.3 pg 0.5 Gerasimovic (1927b) 2423806.919 -1467 +22.627 vis 1 Beyer (1927) 2424105.6 -1447 +21.3 pg 0.5 Gerasimovic (1927b) 2424255.315 -1436 +20.978 vis 1 Beyer (1927) 2424390.7 -1426 +20.0 pg 0.5 Gerasimovic (1927b) 2424758.807 -1399 +19.873 vis 1 Beyer (1927) 2424880.4 -1390 +18.7 pg 0.5 Gerasimovic (1927b) 2425166.947 -1369 +18.881 vis 1 Beyer (1934a) 2425520.728 -1343 +18.080 vis 1 Beyer (1934a) 2426282.663 -1287 +16.301 vis 1 Kukarkin (1940) 2426623.239 -1262 +15.934 vis 1 Kukarkin (1932c) 2426691.049 -1257 +15.555 vis 1 Dunst (1933) 2428458.06 -1127 +9.66 p9 0 Fu De-Lian (1964) 2429604.696 -1043 +10.724 pg 1 Efremov (1958) 2430638.866 -967 +8.425 vis 0.5 Stein (1944) 2430653.134 -966 +9.056 pg 1 Filin (1958) 2431525.288 -902 +8.394 pg 1 Filin (1958) 2432805.023 -808 +6.181 pg 1 Filin (1958) 2433186.576 -780 +5.877 pg 1 Filin (1958) 2434249.160 -702 +4.716 pg 1 Efremov (1958) 2434893.313 -655 +7.895 pg 0 Filin (1958) 2436457.166 -540 +3.407 pg 1 Makarenko (1969) 2436484.05 -538 +3.02 pg 0.5 Smykov (1980) 2436606.84 -529 +3.07 pg 0.5 Vasil'yan. et al.^2 (1970) 2436824.793 -513 +2.815 pe 3 Oosterhoff (1960) 2436838.243 -512 +2.627 pe 3 Weaver et al. (1960) 2436892.930 -508 +2.763 pe 3 Bahner et al. (1962) 2437205.92 -485 +2.09 pg 0.5 Smykov (1980) 2437615.141 -455 +2.174 pg 1 Makarenko (1969) 2437968.44 -429 +0.89 pg 0 Smykov (1980) 2438201.44 -412 +2.05 pg 0.5 Vasil'yan, et al.^2 (1970) 2438295.77 -405 +0.92 pg 0 Smykov (1980) 2438664.78 -378 +1.71 pg 0.5 Vasil'yan. et al.^2 (1970) 2438665.010 -378 +1.936 pg 1 Makarenko (1969) 2439059.47 -349 +0.90 pg 0.5 Smykov (1980) 2441500.2 -170 +0.5 vis 0.5 Cragg (1976) Table 17 (cont.) Obs.Max.J.D. E O-C Type w Reference 2442303.91 -111 -0.44 pg 0.5 Smykov (1980) 2442372.39 -106 -0.15 pg 0.5 Smykov (1980) 2442699.48 -82 -0.37 pg 0.5 Smykov (1980) 2443817.966 0 -0.176 pe 3 present paper Remarks: 1 Observer: Hartwig; 2 Observer: Shakhovskaya
Figure 26 O-C diagram of SZ Cas TT Aquilae Its light and colour curves are plotted in Fig. 27. This variable has a faint companion within the edge of the diaphragm. The O-C residuals have been calculated using the formula: C = 2443810.823 + 13.754707d*E The period of TT Aql has been constant since J.D. 2425000. Before that date the period might have had another value but that part of the O-C diagram (see Fig. 28) is very uncertain.
Figure 27 B, B-V and U-B curves of TT Aql
Figure 28 O-C diagram of TT Aql Table 18 O-C residuals for TT Aql Obs.Max.J.D. E O-C Type w Reference 2411873.865 -2322 +1.472d pg 0.5 Pickering (1907) 2417744.514 -1895 -1.139 pg 1 Jordan (1919) 2417745.486 -1895 -0.167 vis 0.5 Ichinohe (1911) 2417800.1 -1891 -0.6 vis 0.5 Pickering (1908) 2420097.402 -1724 -0.306 pg 0.5 Robinson (1933) 2423742.991 -1459 +0.286 vis 1 Kukarkin^1 (1940) 2425613.245 -1323 -0.101 vis 1 Kukarkin (1940) 2425805.920 -1309 +0.008 vis 0.5 Parenago (1938) 2426466.209 -1261 +0.072 vis 1 Kukarkin (1940) 2426521.173 -1257 +0.017 vis 0.5 Zverev (1936) 2427085.125 -1216 +0.026 vis 1 Florya, Kukarkina (1953) 2427662.80 -1174 0.00 vis 0.5 Krebs^2 (1940) 2428089.378 -1143 +0.185 vis 0.5 Dziewulski et al. (1956) 2428584.5 -1107 +0.1 vis 0.5 Krebs (1939) 2429519.731 -1039 +0.049 pg 0.5 Solov'yov (1944) 2429835.963 -1016 -0.078 pg 1 Erleksova (1960) 2430564.956 -963 -0.084 pg 1 Erleksova (1960) 2431527.765 -893 -0.105 pg 1 Erleksova (1960) 2432449.337 -826 -0.098 pg 1 Erleksova (1960) 2433109.654 -778 -0.007 pe 3 Eggen (1951) 2433494.741 -750 -0.052 pg 1 Erleksova (1960) 2434416.368 -683 +0.010 pg 1 Erleksova (1960) 2435282.936 -620 +0.031 pe 2 Irwin (1961) 2435502.954 -604 -0.026 pg 1 Erleksova (1960) 2435558.014 -600 +0.015 pe 2 Walraven et al. (1958) 2436218.152 -552 -0.073 pg 1 Erleksova (1960) 2437208.525 -480 -0.039 pe 3 Mitchell et al. (1964) 2437469.787 -461 -0.116 pg 0.5 Zoj Von Shor (1963) 2437937.601 -427 +0.038 pe 1 Williams (1966) 2440867.193 -214 -0.123 pe 1 Evans (1976) 2440867.331 -214 +0.015 pe 3 Pel (1976) 2441500.0 -168 0.0 vis 0.5 Cragg (1976) 2441912.777 -138 +0.104 pe 3 Landis (1976) 2442916.670 -65 -0.097 pe 2 Dean (1977) 2443810.884 0 +0.061 pe 3 present paper Remarks: 1 Observer: Kanda 2 Observer: Loreta TX Cygni The light and colour curves of this Cepheid are shown in Fig. 29. The O-C residuals have been computed with the formula: C = 2443794.231 + 14.708157d*E Although the G.C.V.S. (Kukarkin et al., 1969-1970) reported a variation in the period of TX Cyg, the period was constant until the sixties (see Fig. 30) with P = 14.708157 . The period change can only be seen on the basis of the recent observations. Assuming that the change in the period occurred at about J.D. 2437000, the new period is P = 14.7098d which can be refined by future observations.
Figure 29 B and B-V curves of TX Cyg
Figure 30 O-C diagram of TX Cyg
Table 19 O-C residuals for TX Cyg
Obs.Max.J.D. E O-C Type w Reference
2415054.388 -1954 -0.104d pg 1 Williams (1900b)
2415099.03 -1951 +0.41 vis 0.5 Williams (1902)
2415613.522 -1916 +0.120 p9 1 Kulikovsky (1933)
2415614.51 -1916 +1.11 vis 0 Williams (1902)
2415731.144 -1908 +0.077 vis 0.5 Zinner^1 (1932)
2415938.65 -1894 +1.67 vis 0 Yendell (1904)
2416320.92 -1868 +1.53 vis 0 Yendell (1904)
2417084.377 -1816 +0.159 vis 0.5 Zinner^1 (1932)
Table 19 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2417511.71 -1787 +0.96d vis 0 Seares (1907)
2417893.095 -1761 -0.072 vis 1 Zeipel (1908)
2417908.0 -1760 +0.1 vis 0.5 Muller, Hartwig^2 (1918-1920)
2418099.158 -1747 +0.077 vis 1 Bilt (1925)
2418172.86 -1742 +0.24 vis 0.5 Muller, Hartwig^2 (1918-1920)
2418496.46 -1720 +0.26 vis 0.5 Muller, Hartwig (1918-1920)
2418554.996 -1716 -0.038 vis 1 Bilt (1925)
2419319.957 -1664 +0.099 vis 1 Bilt (1925)
2420395.5 -1591 +1.9 vis 0 Yendell (1915)
2420643.670 -1574 +0.078 vis 1 Doberck (1920b)
2421570.143 -1511 -0.063 vis 1 Doberck (1920b)
2422187.816 -1469 -0.132 vis 1 Doberck (1920b)
2422511.750 -1447 +0.222 vis 1 Leiner (1925)
2422894.003 -1421 +0.063 vis 1 Leiner (1925)
2423040.836 -1411 -0.185 p9 1 Henroteau (1924)
2423246.928 -1397 -0.008 vis 1 Leiner (1925)
2423526.414 -1378 +0.023 vis 1 Doberck (1924b)
2423658.906 -1369 +0.142 vis 1 Leiner (1925)
2424040.967 -1343 -0.209 vis 1 Leiner (1925)
2426909.179 -1148 -0.088 vis 1 Florya, Kukarkina (1953)
2427291.667 -1122 -0.012 vis 1 Florya, Kukarkina (1953)
2428674.389 -1028 +0.143 vis 0.5 Dziewulski (1949)
2428909.736 -1012 +0.160 pg 0.5 Shteiman^3 (1958)
2428982.9 -1007 -0.2 vis 0.5 Krebs (1939)
2429174.308 -994 -0.015 vis 1 Conceicao-Silva (1949)
2430086.220 -932 -0.009 vis 1 Conceicao-Silva (1949)
2430704.128 -890 +0.157 vis 1 Conceicao-Silva (1949)
2430998.028 -870 -0.106 pg 1 Solov'yov (1950)
2432719.114 -753 +0.125 pg 1 Solov'yov (1950)
2433130.754 -725 -0.063 p9 1 Solov'yov (1950)
2434307.370 -645 -0.100 pg 1 Shteiman (1958)
2436087.069 -524 -0.088 pg 0.5 Korovkina (1958)
2436440.72 -500 +0.57 pg 0 Korovkina (1959)
2436778.400 -477 -0.040 pe 3 Weaver et al. (1960)
2436793.138 -476 -0.010 pe 3 Oosterhoff (1960)
2436837.432 -473 +0.159 vis 0.5 Busch, Haussler (1968)
2437190.466 -449 +0.197 vis 0.5 Busch, Haussler (1968)
2437219.971 -447 +0.286 pe 1 Mitchell et al. (1964)
2437543.356 -425 +0.092 vis 0.5 Busch, Haussler (1968)
2437955.031 -397 -0.062 pe 1 Williams (1966)
2438323.369 -372 +0.572 vis 0.5 Busch, Haussler (1968)
2438911.485 -332 +0.362 vis 0.5 Busch, Haussler (1968)
2443794.971 0 +0.740 pe 3 present paper
Remarks: 1 Observer: Hartwig; 2 Obs.: Belyavsky; 3 Obs: Milstein Nikolayev
RW Cassiopeiae
The light and colour curves of RW Cas are plotted in Fig. 31.
The O-C residuals have been calculated using the ephemerides:
C_{max} = 2443829.972 + 14.791548d*E
C_{med} = 2443829.215 + 14.791548d*E
Figure 31 B and B-V curves of RW Cas
Figure 32 O-C diagram of RW Cas
for the maximum and median brightnesses, respectively. The period of RW Cas is continuously
decreasing (see Fig. 32). The least squares fitting procedure has resulted in the formula:
(O-C)_{par} = -3.20d*10^{-6}*E^2
for the fitted parabola.
Table 20 O-C residuals for RW Cas
(maximum brightness)
Obs.Max.J.D. E O-C Type w Reference
2414988.475 -1949 -12.770d pg 1 Ceraski (1905)
2416913.376 -1819 -10.770 pg 1 Kukarkin (1932b)
2417327.602 -1791 -10.708 vis 1 Kulikovsky^1 (1935)
2417461.95 -1782 -9.48 vis 0.5 Seares (1907)
2417565.095 -1775 -9.879 vis 1 Pracka (1909)
2417610.025 -1772 -9.324 vis 1 Hartwig (1910)
2417832.029 -1757 -9.193 vis 1 Graff (1921a)
2418763.907 -1694 -9.183 pg 1 Whittaker et al. (1911)
2419651.734 -1634 -8.849 pg 0.5 Robinson (1933)
2420466.157 -1579 -7.961 vis 0.5 Kukarkin^2 (1932b)
2421650.497 -1499 -6.945 pg 1 Kukarkin (1932b)
2422125.956 -1467 -4.815 vis 0 Graff (1921a)
2423500.864 -1374 -5.521 vis 1 Nielsen^3 (1927a)
2424018.179 -1339 -5.910 vis 0.5 Kukarkin^4 (1932b)
2424077.975 -1335 -5.280 vis 1 Kulikovsky' (1935)
2425394.993 -1246 -4.710 vis 1 Kukarkin (1932b)
Kulikovsky^5 (1935)
2425424.937 -1244 -4.349 pg 1 Kukarkin (1932b)
2425557.29 -1235 -5.12 pg 0.5 Kiehl, Hopp (1977)
2425868.248 -1214 -4.785 vis 1 Beyer (1934a)
2426208.442 -1191 -4.796 vis 1 Lassovszky (1932a)
2426223.87 -1190 -4.16 pg 0.5 Kiehl, Hopp (1977)
2426416.318 -1177 -4.002 vis 1 Beyer (1934a)
2427155.692 -1127 -4.205 vis 1 Beyer (1934a)
2428250.826 -1053 -3.646 vis 0.5 Dziewulska (1948)
2428458.06 -1039 -3.49 pg 0.5 Fu De-Lian (1964)
2429286.31 -983 -3.57 vis 0.5 Parenago^6 (1956)
2429953.14 -938 -2.36 vis 0.5 Conceicao-Silva (1948)
2433178.259 -720 -1.798 pe 2 Eggen (1951)
2433622.04 -690 -1.76 vis 0.5 Parenago^6 (1956)
2436478.11 -497 -0.46 pg 0.5 Smykov (1978)
2436891.747 -469 -0.989 pe 3 Bahner et al. (1962)
2436995.411 -462 -0.866 pg 1 Shinada et al. (1969)
2437587.153 -422 -0.786 pe 3 Mitchell et al. (1964)
2437587.24 -422 -0.70 pg 0.5 Smykov (1978)
2437779.760 -409 -0.469 pg 1 Shinada et al. (1969)
2437956.907 -397 -0.820 pe 1 Williams (1966)
2438475.018 -362 -0.414 pg 1 Shinada et al. (1969)
2438652.39 -350 -0.54 pg 0.5 Smykov (1978)
2439776.710 -274 -0.378 pe 3 present paper^7
2440708.91 -211 -0.04 pg 0.5 Smykov (1978)
2441596.78 -151 +0.33 pg 0.5 Smykov (1978)
2442085.86 -118 +1.29 vis 0 Small (1974)
2442499.16 -90 +0.43 pg 0.5 Smykov (1978)
2443667.50 -11 +0.24 pg 0.5 Smykov (1978)
2443830.363 0 +0.391 pe 3 present paper
Table 20 (cont.)
Remarks: I Observer: Blazhko; 2 Obs.: Luizet; 3 Obs.: Aage Nielsen;
4 Obs.: Selivanov; 2 Obs.: Kukarkin; 6 Obs.: Latyshev; 7 Obs.: Abaffy
Table 21 O-C residuals for RW Cas
(median brightness)
Obs.Med.J.D. E O-C Type W Reference
2418763.063 -1694 -9.270d pg 1 Whittaker et al. (1911)
2426207.657 -1191 -4.824 vis 1 Lassovszky (1932a)
2436891.022 -469 -0.957 pe 3 Bahner et al. (1962)
2437586.399 -422 -0.783 pe 3 Mitchell et al. (1964)
2443829.608 0 +0.393 pe 3 present paper
SZ Cygni
The light and colour curves of SZ Cyg are shown in Fig. 33. The variable has a B4
photometric companion (Madore, 1977).
Figure 33 B and B-V curves of SZ Cyg The O-C residuals have been computed with the formula: C = 2443760.128 + 15.109642d*E The O-C diagram of SZ Cyg is plotted in Fig. 34 using the residuals listed in Table 22 except the first one (Deichmuller, 1900a). The O-C diagram has a sinusoidal structure as is to be expected for a member of a binary system with an inclination significantly different from zero, due to the light-time effect. The orbital period of the system is roughly 60-70 years. Spectroscopic observations of SZ Cyg are badly needed since the only radial velocity measurements are those of Joy (1937).
Figure 34 O-C diagram of SZ Cyg Table 22 O-C residuals for SZ Cyg Obs.Max.J.D. E O-C Type w Reference 2406484.5 -2467 -0.1d vis 0.5 Deichmuller (1900a) 2414991.044 -1904 -0.326 pg 1 Williams (1900a) 2415021.853 -1902 +0.264 vis 0.5 Williams (1900a) 2415172.363 -1892 -0.322 vis 0.5 Esch (1936) 2415278.6 -1885 +0.1 vis 0.5 Deichmuller (1900b) 2415399.359 -1877 +0.468 vis 1 Zinner^1 (1932) 2415973.353 -1839 -0.143 pg 1 Florya, Parenago (1933) 2416078.85 -1832 -0.41 vis 0.5 Yendell (1904) 2416441.125 -1808 -0.770 vis 0 Furness^2 (1913b) 2416714.161 -1790 +0.292 vis 0.5 Lau (1907) 2417091.500 -1765 -0.110 vis 1 Nijland (1923) 2417182.386 -1759 +0.118 vis 1 Zinner^1 (1932) 2417499.452 -1738 -0.118 pg 1 Florya, Parenago (1933) 2417665.585 -1727 -0.191 vis 1 Nijland (1923) 2417771.959 -1720 +0.415 vis 1 Luizet (1908a) 2417786.208 -1719 -0.445 vis 0.5 Graff (1914) 2417907.751 -1711 +0.220 vis 1 Zeipel (1908) 2420657.495 -1529 +0.010 vis 1 Doberck (1920a) 2421548.993 -1470 +0.039 vis 1 Doberck (1920a) 2422198.794 -1427 +0.125 vis 1 Doberck (1920a) 2422667.246 -1396 +0.178 pg 1 Henroteau (1924) 2423028.962 -1372 -0.737 vis 0 Eaton^3 (1920 1921,1922, 1923) and Walker^3 (1921) 2423513.067 -1340 -0.141 vis 1 Doberck (1924a) 2423573.673 -1336 +0.027 vis 1 Eaton^4 (1922,1923,1924) 2424374.528 -1283 +0.071 vis 1 Campbell^4 (1925, 1926) 2425174.974 -1230 -0.294 vis 1 Campbell^4 (1927, 1928) 2425749.422 -1192 -0.013 vis 1 Beyer (1934a) 2425900.762 -1182 +0.231 vis 1 Campbell^4 (1929, 1930) 2425976.176 -1177 +0.097 vis 1 Lassovszky (1932b) 2426520.192 -1141 +0.166 vis 1 Beyer (1934a) 2426626.566 -1134 +0.772 vis 0 Campbell^4 (1931, 1932) 2426822.299 -1121 +0.080 vis 1 Lassovszky (1932b) Table 22 (cont.) Obs.Max.J.D. E O-C Type w Reference 2426912.898 -1115 +0.021d vis 1 Florya, Kukarkina (1953) 2426913.31 -1115 +0.43 pg 0.5 Sandig (1948) 2427275.777 -1091 +0.268 vis 1 Florya, Kukarkina (1953) 2427351.2 -1086 +0.1 vis 0.5 Miczaika (1934b) 2427517.521 -1075 +0.258 vis 1 Campbell^4 (1933,1934,1935) 2427576.71 -1071 -0.99 pg 0 Sandig (1948) 2427593.60 -1070 +0.79 vis 0 Solov'yov (1935) 2428197.437 -1030 +0.240 vis 0.5 Dziewulski (1948a) 2428530.03 -1008 +0.42 pg 0.5 Sandig (1948) 2428997.6 -977 -0.4 vis 0.5 Krebs (1939) 2429330.464 -955 +0.044 pg 0.5 Uranova (1950) 2429360.17 -953 -0.47 pg 0.5 Sandig (1948) 2430659.819 -867 -0.249 pg 1 Filin (1951) 2431702.567 -798 -0.067 pg 1 Filin (1951) 2432201.239 -765 -0.013 pg 1 Kulikov (1957) 2432820.760 -724 +0.013 pg 1 Filin (1951) 2434588.194 -607 -0.381 pg 1 Kulikov (1957) 2435389.154 -554 -0.232 pg 1 Kulikov (1957) 2436779.369 -462 -0.104 pe 3 Oosterhoff (1960) 2436794.540 -461 -0.043 pe 3 Weaver et al. (1960) 2436839.40 -458 -0.51 vis 0.5 Busch et al. (1964) 2437202.34 -434 -0.20 vis 0.5 Busch et al. (1964) 2437217.632 -433 -0.021 pe 2 Mitchell et al. (1964) 2437927.38 -386 -0.43 vis 0.5 Busch et al. (1964) 2437942.574 -385 -0.342 pg 1 Girnyak (1971) 2438229.979 -366 -0.020 pe 3 Kwee, Braun (1967) 2439302.479 -295 -0.305 pg 1 Girnyak (1971) 2443760.486 0 +0.358 pe 3 present paper Remarks: 1 Observer: Hartwig; 2 Obs.: Whitney 3 Obs.: McAteer 4 Obs.: Peltier SV Monocerotis The light and colour curves of SV Mon are shown in Fig. 35. The O-C residuals have been calculated using the formula: C = 2443794.338 + 15.232780d*E The period has been constant with the value used in the ephemeris since J.D. 2433000; earlier reliable values for the period cannot be determined (see Fig. 36). Table 23 O-C residuals for SV Mon Obs.Max.J.D. E O-C Type w Reference 2419041.759 -1625 +0.689d pg 0.5 Robinson (1933) 2422621.464 -1390 +0.690 vis 1 Esch (1921) 2422728.089 -1383 +0.686 vis 1 Leiner (1921) 2423047.978 -1362 +0.686 vis 1 Leiner (1926b) 2423459.184 -1335 +0.607 vis 1 Leiner (1926b) 2423809.690 -1312 +0.759 vis 1 Leiner (1926b) 2424419.659 -1272 +1.417 vis 0.5 Leiner (1926b) 2427008.827 -1102 +1.013 vis 1 Florya, Kukarkina (1953)
Figure 35 B, B-V and U-B curves of SV Mon Table 23 (cont.) Obs.Max.J.D. E O-C Type w Reference 2429964.707 -908 +1.733d vis 0 Esch (1936) 2431608.67 -809 +0.56 vis 0.5 Nielsen^1 (1955) 2433192.420 -696 +0.097 p9 1 Satyvaldiev (1970) 2434045.326 -640 -0.033 pg 1 Satyvaldiev (1970) 2435477,219 -546 -0.021 pe 3 Walraven et al. (1958) 2435538.224 -542 +0.053 p9 1 Satyvaldiev (1970) 2436848.276 -456 +0.086 p9 1 Satyvaldiev (1970) 2437564.109 -409 -0.022 pe 3 Mitchell et al. (1964) 2437899.291 -387 +0.039 pe 2 Eggen (1969) 2438097.263 -374 -0.015 pg 1 Fridel^1 (1971) 2438386.627 -355 -0.074 pg 1 Satyvaldiev (1970) 2439209.191 -301 -0.080 pe 2 Wamsteker (1972) 2439346.203 -292 -0.163 pe 2 Takase (1969) 2440732.705 -201 +0.156 pe 3 Pel (1976) 2441493.5 -151 -0.7 vis 0 Cragg (1976) Table 23 (cont.) Obs.Max.J.D. E O-C Type w Reference 2442865.108 -61 -0.030d pe 2 Dean (1977) 2443794.342 0 +0.004 pe 3 present paper Remark: 1 Observer: Arthur Nielsen
Figure 36 O-C diagram of SV Mon X Cygni
Figure 37 B, B-V and U-B curves of X Cyg The light and colour curves of this bright Cepheid are shown in Fig. 37. According to Madore (1977) X Cyg has a B4 photometric companion.
Figure 38 O-C diagram of X Cyg
Figure 39 Deviations from the mean O-C curve
The O-C residuals have been computed using the formula:
C = 2443830.387 + 16.386332d*E
The O-C diagram in Fig. 38 shows a slow period increase. The equation of the approximate
parabola is as follows:
(O-C)_{par} = 1.01d*10^{-7}*E^2
The O-C residuals based on photoelectric and photographic observations show some systematic
deviations from the above mentioned parabola. These Delta(O-C) deviations as a function of
time are plotted in Fig. 39. Although a sinusoidal wave can be seen in this latter figure
as if it were a result of the light-time effect, no variation can be found in the mean
radial velocity of the star (Abt, 1978; Duncan, 1921; Evans, 1976). Only radial velocity
observations made at different phases of the 55 year long cycle can resolve the problem.
Table 24 O-C residuals for X Cyg
Obs.Max.J.D. E O-C Type w Reference
2410255.77 -2049 +0.98d vis 0.5 Chandler (1887)
2410256.02 -2049 +1.23 vis 0.5 Sawyer (1896)
2410551.04 -2031 +1.29 vis 0.5 Sawyer (1896)
2410568.28 -2030 +2.15 vis 0 Chandler (1887)
2410895.34 -2010 +1.48 vis 0.5 Sawyer (1896)
2410928.65 -2008 +2.02 vis 0.5 Yendell (1889a)
2411239.67 -1989 +1.70 vis 0.5 Yendell (1890a)
2411272.12 -1987 +1.38 vis 0.5 Sawyer (1896)
2411616.15 -1966 +1 .29 vis 0.5 Yendell (1891a)
2411632.0 -1965 +0.8 vis 0.5 Gore (1892)
2411927.45 -1947 +1.25 vis 0.5 Duner (1892)
2412009.41 -1942 +1.28 vis 0.5 Yendell (1892a)
2412321.05 -1923 +1.58 vis 0.5 Duner (1893)
2412354.09 -1921 +1.85 vis 0.5 Yendell (1893a)
2412648.46 -1903 +1.26 vis 0.5 Corder (1894)
2412778.634 -1895 +0.346 vis 1 Moraes Pereira (1894)
2412829.563 -1892 +2.116 vis 0 Porro (1896)
2413025.97 -1880 +1.89 vis 0.5 Yendell (1895a)
2413107.12 -1875 +1.11 vis 0.5 Sawyer (1896)
2413336.29 -1861 +0.87 vis 0.5 Sperra (1895, 1896)
2413517.15 -1850 +1.48 vis 0.5 Hisgen (1896)
2413746.38 -1836 +1.30 vis 0.5 Sperra (1897b)
2413763.35 -1835 +1.88 vis 0.5 Yendell (1897)
2414204.170 -1808 +0.271 vis 1 Pickering (1904)
2414516.24 -1789 +1.00 vis 0.5 Luizet (1902a)
2414860.26 -1768 +0.91 vis 0.5 Luizet (1902a)
2414876.68 -1767 +0.94 vis 0.5 Yendell (1900)
2415204.68 -1747 +1.22 vis 0.5 Luizet (1902a)
2415269.413 -1743 +0.403 vis 1 Prittwitz (1907)
2415336.06 -1739 +1.50 vis 0.5 Yendell (1902a)
2415630.60 -1721 +1.09 vis 0.5 Luizet (1902a)
2415941.28 -1702 +0.43 vis 0.5 Yendell (1904)
2416351.66 -1677 +1.15 vis 0.5 Luizet (1912)
2416832.0 -1648 +6.8 vis 0 Furness^1 (1913a)
2416907.893 -1643 +0.249 vis 1 Prittwitz (1907)
2417039.215 -1635 +0.481 vis 1 Nijland (1923)
2417055.372 -1634 +0.251 p9 1 Wilkens (1906)
2417252.71 -1622 +0.95 vis 0.5 Luizet (1912)
2417530.338 -1605 +0.014 vis 1 Nijland (1923)
2417694.729 -1595 +0.542 p9 1 Jordan (1919)
2417743.921 -1592 +0.575 vis 1 Zeipel (1908)
2417810.20 -1588 +1.31 vis 0 Sperra (1909)
2418203.17 -1564 +1.01 vis 0.5 Luizet (1912)
2419104.41 -1509 +1.00 vis 0.5 Luizet (1912)
2419939.103 -1458 -0.012 vis 0.5 Kaiser (1915)
2419988.558 -1455 +0.284 vis 0.5 Kaiser (1915)
2420201.98 -1442 +0.68 vis 0.5 Dziewulski (1924a)
2420300.083 -1436 +0.469 vis 0.5 Hoffmeister (1916a)
2421512.089 -1362 -0.114 pg 0.5 Robinson (1933)
2422134.891 -1324 +0.008 vis 1 Leiner (1926b)
2422478.780 -1303 -0.216 vis 1 Leiner (1926b)
Table 24 (cont.)
Obs.Max.J.D. E O-C Type W Reference
2422970.460 -1273 -0.126d vis 1 Hellerich (1922)
2423183.584 -1260 -0.025 pg 1 Henroteau (1924)
2423364.017 -1249 +0.159 vis 1 AFOEV^2 (1922, 1923)
2423675.346 -1230 +0.147 vis 1 Hellerich (1925)
2424314.718 -1191 +0.452 vis 1 Parenago (1938)
2424675.22 -1169 +0.46 vis 0.5 Azarnova^3 (1956)
2425117.137 -1142 -0.059 pg 1 Hellerich (1935)
2425133.508 -1141 -0.074 vis 1 Kukarkin (1940)
2425231.5 -1135 -0.4 vis 0.5 Lause (1937)
2425478.101 -1120 +0.406 vis 1 Parenago (1938)
2425559.129 -1115 -0.498 pg 0.5 Iwanowska et al. (1932)
2425690.504 -1107 -0.213 vis 1 Zverev (1936)
2426296.989 -1070 -0.023 vis 1 Kukarkin (1940)
2426428.000 -1062 -0.102 vis 1 Zverev (1936)
2426804.859 -1039 -0.129 pg 1 Kox (1935)
2426903.261 -1033 -0.045 vis 0.5 Dziewulski et al. (1948)
2426919.614 -1032 -0.078 vis 1 Florya, Kukarkina (1953)
2426919.975 -1032 +0.283 vis 1 Parenago (1938)
2427148.928 -1018 -0.173 pg 1 Dziewulski (1948b)
2427264.372 -1011 +0.567 vis 1 Jaschek (1938)
2427280.529 -1010 +0.337 vis 1 Florya, Kukarkina (1953)
2427328.968 -1007 -0.383 pg 1 Liau (1935)
2427624.336 -989 +0.031 vis 0.5 Dziewulski et al. (1948)
2427886.915 -973 +0.429 vis 1 Jaschek (1938)
2427951.757 -969 -0.274 vis 1 Miczaika (1937)
2428001.425 -966 +0.235 vis 1 Krebs (1936)
2428672.816 -925 -0.214 pg 1 Dziewulski (1948b)
2429050.036 -902 +0.120 vis 1 Conceicao-Silva (1949)
2430164.128 -834 -0.058 vis 1 Conceicao-Silva (1949)
2430819.740 -794 +0.101 vis 1 Conceicao-Silva (1949)
2433031.783 -659 -0.011 pe 3 Eggen (1951)
2433146.670 -652 +0.171 vis 1 Chadov (1953)
2433490.3 -631 -0.3 vis 0.5 Domke, Pohl^4 (1953)
2433491.1 -631 +0.5 vis 0.5 Domke, Pohl^5 (1953)
2433605.249 -624 -0.067 pg 1 Romano (1951)
2433638.317 -622 +0.229 vis 1 Chadov (1953)
2434605.093 -563 +0.211 pe 3 present paper^6
2435015.398 -538 +0.858 vis 0.5 Azarnova (1956)
2435196.43 -527 +1.64 vis 0 Marks (1959)
2436096.180 -472 +0.142 pe 1 Svolopoulos (1960)
2436129.522 -470 +0.711 vis 0.5 Azarnova (1959)
2436259,812 -462 -0.090 vis 1 Latyshev (1969)
2436898.988 -423 +0.019 vis 1 Azarnova (1962)
2436964.715 -419 +0.201 vis 1 Mayall^7 (1964)
2437226.867 -403 +0.172 pe 3 Mitchell et al. (1964)
2437898.718 -362 +0.183 pe 3 Williams (1966)
2438881,767 -302 +0.052 pe 3 Wisniewski, Johnson (1968)
2439782.931 -247 -0.032 pe 3 present papers^8
2440914,30 -178 +0.68 vis 0.5 Braune et al.^9 (1972)
2440929.879 -177 -0.127 pe 2 Evans (1976)
2441618,198 -135 -0.034 pe 3 Landis (1973)
2442372.254 -89 +0.251 vis 0.5 Berdnikov (1977)
2443830.274 0 -0.113 pe 3 present paper
Remarks: (Observers) 1 Whitney; 2 Ellsworth, Bernard, Houdard;
3 Vorontsov-Veliaminov; 4 Mielke; 5 Sofronijewic; 6 Detre; 7 Oravec; 8 Abaffy;
9 Bauer
RW Camelopardalis
The light and colour curves of RW Cam are plotted in Fig. 40. The amplitude of the
light variation is smaller than that given by Schaltenbrand and Tammann (1971). According
to Madore (1977) this variable has a B2 photometric companion. The presence of an early
type companion was also reported by Miller and Preston (1964).
Figure 40 B, B-V and U-B curves of RW Cam
Figure 41 O-C diagram of RW Cam The O-C residuals have been calculated with the ephemeris: C = 2443840.620 + 16.414812d*E The O-C diagram in Fig. 41 also shows the presence of the companion. Table 25 O-C residuals for RW Cam Obs.Max.J.D. E O-C Type w Reference 2417955.185 -1577 +0.724d vis 1 Enebo (1908) 2420876.433 -1399 +0.135 pg 0.5 Robinson (1933) 2427015.703 -1025 +0.265 vis 1 Florya, Kukarkina (1953) 2427130.150 -1018 -0.191 vis 0 Dziewulski et al. (1946) 2427902.012 -971 +0.174 vis 0.5 Dziewulski (1947) 2428575.084 -930 +0.239 pg 0.5 Dziewulski et al. (1946) 2430643.017 -804 -0.094 pg 1 Filin (1958) 2432169.750 -711 +0.061 pg 1 Filin (1958) 2433909.575 -605 -0.084 pg 1 Filin (1958) 2436174.873 -467 -0.030 pe 3 Bahner et al. (1977) 2436552.861 -444 +0.418 pg 0.5 Nikulina (1970) 2436831.480 -427 -0.015 pe 3 Oosterhoff (1960) 2436831.546 -427 +0.051 pe 3 Weaver et al. (1960) 2436880.608 -424 -0.132 pe 3 Bahner et al. (1962) 2437964.318 -358 +0.201 pe 1 Williams (1966) 2438358.045 -334 -0.028 pg 0.5 Nikulina (1970) 2439113.340 -288 +0.186 pe 3 Wamsteker (1972) 2439786.182 -247 +0.021 pe 2 present paper^1 2443840.515 0 -0.105 pe 3 present paper Remark: 1 Observer: Abaffy Table 26 Obs.Max.J.D. O-C Phase Obs.Max.J.D. O-C Phase 2430643.017 -0.094d .097 2436880.608 -0.132 .043 2432169.750 +0.061 .329 2437964.318 +0.201 .207 2433909.575 -0.084 .592 2439113.340 +0.186 .381 2436174.873 -0.030 .936 2439786.182 +0.021 .483 243683.480 -0.015 .035 2443840.515 -0.105 .097 2436831.546 +0.051 .035
Figure 42 O-C variations due to orbital motion
After J.D. 2430000 a wave-like structure can clearly be seen. The probable orbital
period is P_{orb} 6600d ą300d (see Table 26 and Fig. 42). Radial velocity measurements would
be needed to check this value of the orbital period since the only series of radial
velocity measurements is that of Joy (1937). Before J.D. 2430000 the period was shorter
than that used in the ephemeris but the accurate value cannot be determined in lack of a
satisfactory number of data points in the O-C diagram.
CD Cygni
The light and colour curves of this Cepheid are plotted in Fig. 43. The O-C
residuals have been derived using the formula:
C = 2443831.167 + 17.073967d*E
Figure 43 B, B-V and U-B curves of CD Cyg
The period of CD Cyg is continuously increasing. The positive parabola shown in Fig. 44 is
a least squares fitted parabola to the O-C residuals. The equation of this parabola is
(O-C)_{par} = 1.54d*10^{-6}*E^2
Figure 44 O-C diagram of CD Cyg Table 27 O-C residuals for CD Cyg Obs.Max.J.D. E O-C Type w Reference 2416891.124 -1578 +2.677d pg 0.5 Kukarkin (1932d) 2421500.608 -1308 +2.190 pg 0.5 Robinson (1933) 2422972.7 -1222 +5.9 vis 0 Kristensen^1 (1923b) 2423276.338 -1204 +2.227 vis 1 Leiner (1924a) 2423327.6 -1201 +2.3 vis 0.5 Kristensen^2 (1923b) 2423344.570 -1200 +2.163 vis 0.5 Kristensen (1923b) 2423634.659 -1183 +1.995 vis 1 Leiner (1924a, 1926a) 2423686.431 -1180 +2.545 vis 0.5 Nielsen^1 (1933) 2423907.775 -1167 +1.927 vis 1 Nielsen^2 (1933) 2423924.936 -1166 +2.015 vis 1 Leiner (1926a) 2424368.905 -1140 +2.060 vis 1 Leiner (1926a) 2424795.868 -1115 +2.174 vis 1 Nielsen^2 (1933) 2424812.738 -1114 +1.970 vis 1 Nielsen^1 (1933) 2425734.623 -1060 +1.861 vis 1 Nielsen2 (1933) 2425853.978 -1053 +1.698 vis 1 Nielsen^1 (1933) 2426434.190 -1019 +1.395 vis 1 Kukarkin (1932d) 2426468.76 -1017 +1.824 vis 1 Nielsen^1 (1933) 2426588.139 -1010 +1.679 vis 1 Nielsen2 (1933) 2428193.727 -916 +2.314 vis 0 Dziewulski (1950) 2428260.945 -912 +1.236 pg 0.5 Wachmann (1966) 2428944.133 -872 +1.465 vis 0.5 Nielsen2 (1952) 2428960.700 -871 +0.958 pg 0.5 Wachmann (1966) 2429148.50 -860 +0.95 pg 0.5 Smirnov (1946) 2429541.628 -837 +1.371 vis 0.5 Nielsen^1 (1952) 2430053.703 -807 +1.227 vis 0.5 Nielsen^3 (1952) 2430121.57 -803 +0.80 vis 0.5 Ashbrook (1943) 2432768.11 -648 +0.87 vis 0.5 Nielsen^4 (1955) 2432888.071 -641 +1.317 pg 0.5 Wachmann (1966) 2433160.98 -625 +1.04 vis 0.5 Nielsen^1 (1955) 2433672.96 -595 +0.80 vis 0.5 Nielsen^5 (1955) 2433740.850 -591 +0.398 pg 0.5 Jagott (1954) 2433928.810 -580 +0.544 p9 1 Shteiman (1958) 2434151.462 -567 +1.234 p9 0 Wachmann (1966) 2434355.773 -555 +0.658 pg 0.5 Jagott (1954) 2435055.408 -514 +0.260 p9 1 Shteiman (1958) 2435107.498 -511 +1.128 pg 0 Wachmann (1966) 2436165.306 -449 +0.350 pe 3 Bahner et al. (1971) Table 27 (cont.) Obs.Max.J.D. E O-C Type w Reference 2436779.890 -413 +0.271d pe 3 Weaver et al. (1960) 2436796.966 -412 +0.273 pe 3 Oosterhoff (1960) 2436899.29 -406 +0.15 vis 0.5 Busch et al. (1964) 2437257.891 -385 +0.201 pe 3 Mitchell et al. (1964) 2437582.34 -366 +0.25 vis 0.5 Busch et al. (1964) 2437940.36 -345 -0.29 vis 0 Busch et al. (1964) 2437957.816 -344 +0.094 pe 1 Williams (1966) 2438231.052 -328 +0.146 pe 3 Kwee, Braun (1967) 2440006.657 -224 +0.059 pe 3 Asteriadis et al. (1977) 2440792.027 -178 +0.026 pe 3 Asteriadis et al. (1977) 2443831.224 0 +0.057 pe 3 present paper Remarks: 1 Observer: Kierulff; 2 Obs.: Vaaben; 3 Obs.: Sjogren; 4 Obs.: Buhl; 5 Obs.: Darnell SZ Aquilae
Figure 45 B, B-V and U-B curves of SZ Aql
Its light and colour curves are shown in Fig. 45. The O-C residuals have been
calculated with the ephemerides:
C_{max} = 2443807.183 + 17.140849d*E
C_{med} = 2443806.524 + 17.140849d*E
for the maximum and median brightnesses, respectively. The period of SZ Aql is continuously
increasing. The equation of the least squares fitted parabola shown in Fig. 46 is
(O-C)_{par} = 2.02d*10^{-6}*E^2.
It is worth mentioning that the rate of the period increase is almost the same as in CD
Cyg. This is important since the difference in the period of the two stars is less than 0.5
per cent.
Figure 46 O-C diagram of SZ Aql Table 28 O-C residuals for SZ Aql (maximum brightness) Obs.Max.J.D. E O-C Type w Reference 2412685.63 -1816 +6.23d pg 0.5 Pickering (1907) 2417740.811 -1521 +4.859 vis 0.5 Ichinohe (1910) 2417809.1 -1517 +4.6 vis 0.5 Pickering (1908) 2419265.600 -1432 +4.113 vis 1 Biesbroeck et al. (1914) 2420258.765 -1374 +3.109 pg 0 Robinson (1933) 2423601.8 -1179 +3.7 vis 0 Hacar (1925) 2427097.073 -975 +2.218 vis 1 Florya, Kukarkina (1953) 2428125.097 -915 +1.791 vis 0.5 Dziewulski (1956b) 2429513.184 -834 +1.469 pg 1 Ahnert (1951) 2429547.473 -832 +1.476 pg 0.5 Solov'yov (1944) 2429838.681 -815 +1.290 pg 1 Erleksova (1960) 2430610.179 -770 +1.450 pg 0.5 Erleksova (1960) 2430832.873 -757 +1.313 pg 0.5 Filin (1948) 2431638.130 -710 +0.950 pg 1 Erleksova (1960) 2432460.734 -662 +0.793 pg 1 Erleksova (1960) 2433112.198 -624 +0.905 pe 3 Eggen (1951) 2433454.820 -604 +0.710 pg 1 Erleksova (1960) 2434414.613 -548 +0.615 pg 1 Erleksova (1960) Table 28 (cont.) Obs.Max.J.D. E O-C Type w Reference 2435494.235 -485 +0.364d pg 1 Erleksova (1960) 2435580.096 -480 +0.521 pe 1 Walraven et al. (1958) 2436231.149 -442 +0.221 pg 1 Erleksova (1960) 2437156.786 -388 +0.252 pe 2 Mitchell et al. (1964) 2437465.336 -370 +0.267 pg 0.5 Zoj Von Shor (1963) 2437945.611 -342 +0.598 pe 1 Williams (1966) 2440910.526 -169 +0.146 pe 3 Pel (1976) 2441495.7 -135 +2.5 vis 0 Cragg (1976) 2442898.836 -53 +0.118 pe 2 Dean (1977) 2443807.095 0 -0.088 pe 3 present paper Table 29 O-C residuals for SZ Aql (median brightness) Obs.Med.J.D. E O-C Type w Reference 2429512.395 -834 +1.339d pg 1 Ahnert (1951) 2433111.359 -624 +0.725 pe 3 Eggen (1951) 2440909.789 -169 +0.068 pe 3 Pel (1976) 2443806.512 0 -0.012 pe 3 present paper YZ Aurigae YZ Aur has a faint companion within the edge of the diaphragm. This may be the reason that the amplitude of the light variation is less than that derived by Schaltenbrand and Tammann
Figure 47 B and B-V curves of YZ Aur (1971). The light curve in Fig. 47 shows the presence of a bump at the bottom of the ascending branch which is normal for a Cepheid with a period of 18 days but was unnoticed on the previous incomplete light curves. The Cepheid variable YZ Aur has a B3 photometric companion (Madore, 1977). The O-C residuals have been computed with the formula: C = 2443816.490 + 18.193212d*E The O-C diagram in Fig. 48 shows a rejumping period: before J.D. 2428000 P = 18.193121d after J.D. 2429000 P = 18.193212d The sudden period change and the rejump of the period took place between J.D. 2428000 and J.D. 2429000.
Figure 48 O-C diagram of YZ Aur
Table 30 O-C residuals for YZ Aur
Obs.Max.J.D. E O-C Type w Reference
2416290.613 -1513 +0.453d pg 1 Yakimov (1962)
2417509.537 -1446 +0.432 vis 1 Williams (1918)
2420420.436 -1286 +0.417 pg 0.5 Robinson (1933)
2421548.525 -1224 +0.526 vis 1 Williams (1918)
2422239.93 -1186 +0.59 vis 0.5 Nijland (1935)
2422786.02 -1156 +0.88 vis 0.5 Nijland (1935)
2423386.79 -1123 +1.28 vis 0 Nijland (1935)
2425205.66 -1023 +0.83 pg 0.5 Oosterhoff (1935)
2425241.720 -1021 +0.499 vis 1 Beyer (1930)
2425587.785 -1002 +0.893 vis 0.5 Beyer (1930)
2425823.62 -989 +0.22 pg 0.5 Oosterhoff (1935)
2426315.010 -962 +0.390 vis 1 Kukarkin (1940)
2426606.26 -946 +0.55 pg 0.5 Oosterhoff (1935)
2426751.640 -938 +0.383 vis 1 Detre (1935)
2427424.795 -901 +0.389 vis 1 Detre (1935)
2428567.99 -838 -2.59 pg 0 Fu De-Lian (1964)
2429170.930 -805 -0.024 pg 1 Yakimov (1962)
2430245.058 -746 +0.704 vis 0 Lagrula (1941, 1942)
2432846.025 -603 +0.042 pg 1 Filatov (1958)
2432973.338 -596 +0.002 pg 1 Yakimov (1962)
2436830.288 -384 -0.009 pe 2 Weaver et al. (1960)
2437376.2 -354 +0.1 pg 0.5 Ahnert (1961)
2443816.489 0 -0.001 pe 3 present paper
VX Cygni
The light and colour curves of this variable are shown in Fig. 49. According to
Madore (1977) VX Cyg has a B7 photometric companion.
The O-C residuals have been calculated using the formula:
C = 2443783.642 + 20.133407d*E
The O-C diagram in Fig. 50 shows a continuous increase in period. The equation of the
fitted parabola is:
(O-C)_{par} = 8.02d*10^{-7}*E^2
Figure 49 B and B-V curves of VX Cyg Table 31 O-C residuals for VX Cyg Obs.Max.J.D. E O-C Type w Reference 2414976.2 -1431 +3.5d pg 0 Williams (1905) 2415337.4 -1413 +2.3 pg 0.5 Williams (1905) 2415477.663 -1406 +1.591 pg 1 Kulikovsky (1933) 2415681.0 -1396 +3.6 pg 0 Williams (1905) 2416423.86 -1359 +1.52 vis 0.5 Williams (1905) 2416424.0 -1359 +1.7 vis 0.5 Hartwig (1903) 2416726.78 -1344 +2.44 vis 0 Williams (1905)
Figure 50 O-C diagram of VX Cyg Table 31 (cont.) Obs.Max.J.D. E O-C Type w Reference 2417471.81 -1307 +2.53d vis 0 Seares (1907) 2417492.5 -1306 +3.1 vis 0 Muller, Hartwig (1918-1920) 2417873.230 -1287 +1.283 vis 1 Bilt (1925) 2417914.44 -1285 +2.23 vis 0 Muller, Hartwig^1 (1918-1920) 2418175.75 -1272 +1.80 vis 0.5 Muller, Hartwig^1 (1918-1920) 2418195.480 -1271 +1.398 vis 1 Bilt (1925) 2418658.210 -1248 +1.060 vis 1 Bilt (1925) 2419524.000 -1205 +1.113 vis 1 Bilt (1925) 2420369.659 -1163 +1.169 pg 0.5 Robinson (1933) 2421597.62 -1102 +0.99 vis 0.5 Parenago^2 (1949) 2422523.743 -1056 +0.979 vis 1 Leiner (1924b) 2422906.248 -1037 +0.949 vis 1 Leiner (1924b) 2423228.236 -1021 +0.803 pg 1 Henroteau (1924) 2423268.681 -1019 +0.981 vis 1 Leiner (1924b) 2423308.602 -1017 +0.635 vis 1 Doberck (1924c) 2423570.397 -1004 +0.696 vis 1 Leiner (1924b) 2423691.429 -998 +0.927 vis 1 Doberck (1924c) 2425925.52 -887 +0.21 pg 0.5 Oosterhoff (1935) 2426349.5 -866 +1.4 vis 0 Miczaika (1936) 2426711.48 -848 +0.97 pg 0.5 Oosterhoff (1935) 2426792.37 -844 +1.32 pg 0 Sandig (1948) 2426912.623 -838 +0.776 vis 1 Florya, Kukarkina (1953) 2426932.67 -837 +0.69 pg 0.5 Oosterhoff (1935) 2427294.665 -819 +0.283 vis 1 Florya, Kukarkina (1953) 2427315.68 -818 +1.17 pg 0.5 Oosterhoff (1935) 2427818.52 -793 +0.67 pg 0.5 Sandig (1948) 2428985.88 -735 +0.29 pg 0.5 Sandig (1948) 2429006.30 -734 +0.58 pg 0.5 Milstein (1946) 2429992.579 -685 +0.321 vis 0.5 Conceicao-Silva (1948) 2430717.381 -649 +0.320 pg 0.5 Nikulina (1970) 2431542.930 -608 +0.399 pg 0.5 Nikulina (1970) 2432670.232 -552 +0.231 pg 0.5 Nikulina (1970) 2433455.217 -513 +0.013 pg 0.5 Nikulina (1970) 2433918.520 -490 +0.247 pg 1 Shteiman (1958) 2434261.138 -473 +0.598 pg 0.5 Nikulina (1970) 2435226.968 -425 +0.024 pg 1 Shteiman (1958) Table 31 (cont.) Obs.Max.J.D. E O-C Type w Reference 2436093.605 -382 +0.924d pg 0 Korovkina (1958) 2436375.695 -368 +1.147 pg 0 Nikulina (1970) 2436434.88 -365 -0.07 pg 0.5 Korovkina (1959) 2436777.320 -348 +0.104 pe 3 Weaver et al. (1960) 2436797.613 -347 +0.263 pe 3 Oosterhoff (1960) 2436858.84 -344 +1.09 vis 0 Busch, Haussler (1968) 2437402.084 -317 +0.732 p9 0 Nikulina (1970) 2438206.277 -277 -0.411 pg 1 Dultsev (1967) 2438670.39 -254 +0.63 vis 0 Busch, Haussler (1968) 2438911.49 -242 +0.13 vis 0.5 Busch, Haussler (1968) 2443783.660 0 +0.018 pe 3 present paper Remarks: 1 Observer: Belyavsky; 2 Observer: Doberck T Monocerotis The light and colour curves (Fig. 51) of this long period Cepheid are incomplete because the weather conditions during the
Figure 51 B, B-V and U-B curves of T Mon observing runs did not permit observation of the star at the missing light curve phases. Based on IUE observations, Mariska et al. (1980) pointed out that T Mon has an A0 III companion.
Figure 52 O-C diagram of T Mon
Figure 53 Deviations from the mean O-C curve
The O-C residuals have been computed with the formula:
C = 2443784.615 + 27.024649d*E
The O-C diagram in Fig. 52 can well be approximated by the parabola:
(O-C)_{par} = 5.34d*10^{-6}E^2
The deviation of each reliable O-C residual from this parabola is plotted in Fig. 53.
These deviations have a wave-like trend. If this wave is attributed
to the light-time effect, the orbital period would be about 100 years. Although the
available radial velocity data are not very homogeneous (Evans, 1976; Sanford, 1927 and
1956, Wallerstein, 1972), the two series of Sanford's observations show a difference of
about 2 km/sec in the average value of the radial velocity, thereby supporting the
observability of the orbital motion.
Table 32 O-C residuals for T Mon
Obs.Max.J.D. E O-C Type w Reference
2405015.8 -1435 +11.6d vis 0.5 Muller, Hartwig^1 (1918-1920)
2405555.8 -1415 +11.1 vis 0,5 Muller, Hartwig^1 (1918-1920)
2405556.62 -1415 +11.88 vis 0.5 Sanford^2 (1927)
2405582.574 -1414 +10.813 vis 1 Valentiner^3 (1900)
2405933.570 -1401 +10.488 vis 1 Valentiner^3 (1900)
2406366.087 -1385 +10.611 vis 1 Valentiner^3 (1900)
2408473.713 -1307 +10.314 vis 1 Sawyer (1883)
2408931.31 -1290 +8.49 vis 0.5 Sawyer (1885)
2409228.94 -1279 +8.85 vis 0.5 Sawyer (1885)
2409578.72 -1266 +7.31 vis 0.5 Sawyer (1887a)
2409930.90 -1253 +8.17 vis 0.5 Sawyer (1887b)
2410335.59 -1238 +7.49 vis 0.5 Sawyer (1888b)
2410660.29 -1226 +7.90 vis 0.5 Sawyer (1888a)
2410714.50 -1224 +8.06 vis 0.5 Yendell (1888)
2411038.63 -1212 +7.89 vis 0.5 Yendell (1889b)
2411066.28 -1211 +8.52 vis 0.5 Sawyer (1890a)
2411415.95 -1198 +6.87 vis 0.5 Sawyer (1890b)
2411416.76 -1198 +7.68 vis 0.5 Yendell (1890b)
2411767.19 -1185 +6.78 vis 0.5 Sawyer (1891)
2411768.05 -1185 +7.64 vis 0.5 Yendell (1891b)
2411957.926 -1178 +8.348 vis 0.5 Markwick (1892, 1894)
2412117.89 -1172 +6.16 vis 0.5 Sawyer (1896)
2412119.37 -1172 +7.64 vis 0.5 Yendell (1892b)
2412468.78 -1159 +5.73 vis 0.5 Sawyer (1896)
2412470.67 -1159 +7.62 vis 0.5 Yendell (1893b)
2412819.31 -1146 +4.94 vis 0 Sawyer (1896)
2412846.711 -1145 +5.319 vis 0.5 Porro (1896)
2412876.16 -1144 +7.74 vis 0.5 Yendell (1894)
2413226.16 -1131 +6.42 vis 0.5 Yendell (1895b)
2413308.11 -1128 +7.30 vis 0.5 Sperra (1895)
2413604.93 -1117 +6.85 vis 0.5 Hisgen (1897)
2413605.20 -1117 +7.1 vis 0.5 Yendell (1897)
2413606 -1117 +8 vis 0 Muller, Hartwig^4 (1918-1920)
2413659.0 -1115 +6.9 vis 0.5 Sperra (1897a)
2414090.032 -1099 +5.506 vis 1 Pickering (1904)
2414308.49 -1091 +7.77 vis 0.5 Yendell (1900)
2414711.75 -1076 +5.66 vis 0.5 Luizet (1902b)
2415089.305 -1062 +4.867 vis 1 Wendell (1909)
2415089.90 -1062 +5.46 vis 0.5 Luizet (1902b)
2415766.55 -1037 +6.50 vis 0.5 Yendell (1902b)
2416278.19 -1018 +4.67 vis 0.5 Nielsen^5 (1930a)
Table 32 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2417061.531 -989 +4.294d vis 1 Nijland (1923)
2417173.63 -985 +8.29 vis 0 Furness^6 (1913b)
2417656.144 -967 +4.365 vis 1 Zeipel (1908)
2417764.361 -963 +4.483 vis 1 Nijland (1923)
2418277.561 -944 +4.215 vis 1 Nijland (1923)
2418385.211 -940 +3.766 vis 1 Bemporad (1910)
2419844.940 -886 +4.164 vis 1 Kaiser (1915)
2419871.505 -885 +3.704 pg 0.5 Robinson (1933)
2419979.4 -881 +3.5 vis 0.5 Dziewulski (1924b)
2420925.705 -846 +3.943 vis 1 Luyten (1922)
2421249.41 -834 +3.35 vis 0.5 Nielsen^7 (1930a)
2421250.411 -834 +4.353 vis 1 Luyten (1922)
2421628.374 -820 +3.971 vis 1 Luyten (1922)
2422383.89 -792 +2.80 vis 0.5 Nielsen^8 (1930a)
2422736.133 -779 +3.720 vis 1 Gallisot (1923)
2423357.40 -756 +3.42 vis 0.5 Nielsen^9 (1930a)
2423790.35 -740 +3.98 vis 0.5 Sanford (1927)
2424086.834 -729 +3.188 vis 1 Eaton^10 (1924),Campbell^10 (1925)
2424221.16 -724 +2.39 vis 0.5 Nielsen^11 (1930a)
2425275.141 -685 +2.411 vis 1 Kukarkin (1940)
2425302.270 -684 +2.515 pg 1 Hellerich (1935)
2425302.9 -684 +3.1 vis 0.5 Lause (1937)
2425383.521 -681 +2.692 vis 1 Ahnert (1929)
2425680.746 -670 +2.646 vis 1 Zverev (1936)
2426356.475 -645 +2.759 vis 1 Zverev (1936)
2427085.110 -618 +1.728 vis 1 Florya, Kukarkina (1953)
2427734.385 -594 +2.412 vis 1 Krebs (1935)
2428193.05 -577 +1.66 vis 0.5 Nielsen (1941b)
2432840.908 -405 +1.276 pe 2 Eggen (1951)
2435191.449 -318 +0.672 pe 2 Irwin (1961)
2435488.134 -307 +0.086 pe 2 Walraven et al. (1958)
2435736.940 -298 +5.670 pg 0 Nikulina (1972)
2437056.133 -249 +0.656 pe 2 Mitchell et al. (1964)
2437974.560 -215 +0.245 pe 1 Williams (1966)
2438758.533 -186 +0.503 pe 3 Wisniewski, Johnson (1968)
2439352.984 -164 +0.411 pe 1 Takase (1969)
2439812.386 -147 +0.394 pe 3 present paper^12
2440919.687 -106 -0.315 pe 3 Pel (1976)
2441001.207 -103 +0.131 pe 1 Evans (1976)
2441514.4 -84 -0.1 vis 0.5 Cragg (1976)
2441730.626 -76 -0.116 pe 3 Landis (1976)
2442001.5 -66 +0.5 vis 0.5 Bohme (1976)
2442298.250 -55 -0.009 vis 0.5 Berdnikov (1977)
2443214.40 -21 -2.70 vis 0 Busch^13 (1977)
2443541.383 -9 -0.010 vis 0.5 Busch^14 (1980)
2443784.184 0 -0.431 pe 3 present paper
2443838.47 +2 -0.19 vis 0.5 Busch^5 (1980)
Remarks: 1 from Uranometria Argentina; Observers: 2 Davis;
3 Schonfeld; 4 Prittwitz; 5 Worsell; 6 Whitney; 7 de Roy;
8 Bemporad; 9 Bernard; 10 Schuller; 11 Aurino; 12 Abaffy;
13 Rummler; 14 Branzke; 15 Richter
SV Vulpeculae
The light and colour curves of the longest period programme star are shown in
Fig. 54. The O-C residuals have been calculated with the formulae:
C_{max} = 2443715.321 + 44.994772d*E
C_{med} = 2443711.336 + 44.994772d*E
for the maximum and median brightnesses, respectively. The O-C diagram can well be
approximated by a parabola after J.D. 2423000, indicating a continuous period shortening
(see Fig. 55). The equation of the fitted parabola is
(O-C)_{par} = -2.063d*10^{-4}*E^2.
Figure 54 B, B-V and U-B curves of SV Vul The deviations from this parabola are plotted in Fig. 56. Although there is a slight indication of a periodicity with P approx 9000 days in this Delta(O-C) diagram, no other indication of the binary nature of SV Vul exists. The available radial velocity measurements (Fernie, 1979; Joy, 1937; Sanford, 1956) show the constancy of the average value of the radial velocity.
Figure 55 O-C diagram of SV Vul Table 33 O-C residuals for SV Vul (maximum brightness) Obs.Max.J.D. E O-C Type w Reference 2415752.59 -620 -65.97d pg 0.5 Gerasimovic (1927a) 2416473.78 -604 -64.70 pg 0.5 Gerasimovic (1927a) 2417422.04 -583 -61.33 pg 0.5 Gerasimovic (1927a) 2418685.27 -555 -57.95 pg 0.5 Gerasimovic (1927a) 2419588.63 -535 -54.49 pg 0.5 Gerasimovic (1927a) 2420536.48 -514 -51.53 pg 0.5 Gerasimovic (1927a)
Figure 56 Deviations from the mean O-C curve
Table 33 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2421394.85 -495 -48.06d pg 0.5 Gerasimovic (1927a)
2422522.70 -470 -45.08 pg 0.5 Gerasimovic (1927a)
2423244.750 -454 -42.945 vis 1 Kristensen^1 (1923a, 1924)
2423470.375 -449 -42.293 vis 1 Leiner (1924c)
2423651.506 -445 -41.141 vis 1 Zakharov (1924a, 1924b)
2423877.492 -440 -40.129 vis 1 Kristensen^1 (1926)
2423923.337 -439 -39.279 vis 1 Beyer (1930)
2423967.382 -438 -40.229 vis 1 Ahnert (1931)
2424013.182 -437 -39.424 vis 1 Zakharov (1928)
2424147.972 -434 -39.618 vis 1 Leiner (1929)
2424329.238 -430 -38.331 vis 1 Zakharov (1928)
2424374.408 -429 -38.156 vis 1 Beyer (1930)
2424419.308 -428 -38.251 vis 1 Nielsen (1927b)
2424511.224 -426 -36.324 vis 1 Ahnert (1931)
2424735.814 -421 -36.708 vis 1 Leiner (1929)
2424736.399 -421 -36.123 vis 1 Beyer (1930)
2424781.074 -420 -36.443 vis 1 Zakharov (1928)
2425142.660 -412 -34.815 vis 1 Beyer (193Q)
2425143.200 -412 -34.275 vis 1 Ahnert (1931)
2425369.141 -407 -33.308 vis 1 Leiner (1929)
2425549.866 -403 -32.562 vis 1 Beyer (1930)
2425865.562 -396 -31.829 vis 1 Ahnert (1931)
2425865.877 -396 -31.514 vis 1 Kukarkin (1940)
2425955.316 -394 -32.065 vis 1 Zakharov (1954a)
2426180.58 -389 -31.77 pg 0.5 Nassau, Townson (3932)
2426180.762 -389 -31.593 vis 1 Ahnert (1931)
2426362.56 -385 -29.77 vis 0.5 Nielsen (1937a)
Table 33 (cont.)
Obs.Max.J.D. E O-C Type w Reference
2426406.297 -384 -31.032dvis 1 Zverev (1936)
2426452.863 -383 -29.460 vis 1 Terkan (1935)
2426677.678 -378 -29.619 vis 1 Kukarkin (1940)
2426904.699 -373 -27.572 vis 1 Florya, Kukarkina (1953)
2427265.340 -365 -26.889 vis 1 Florya, Kukarkina (1953)
2427309.0 -364 -28.2 vis 0.5 Miczaika (1934a)
2427762.809 -354 -24.363 vis 0.5 Dziewulski et al. (1947)
2428032.45 -348 -24.69 vis 0.5 Nielsen' (1952)
2428077.005 -347 -25.130 pg 1 Nassau, Ashbrook (1942)
2428422.03 -340 +4.93 pg 0 Fu De-Lian (1964)
2428753.872 -332 -23.185 pg 1 Dziewulski et al. (1946)
2429025.37 -326 -21.65 pg 0.5 Kholopov (1946)
2430695.04 -289 -16.79 vis 0.5 Nielsen^3 (1952)
2430695.11 -289 -16.72 vis 0.5 Kukarkin (1951)
2432362.68 -252 -13.96 vis 0.5 Nielsen^3 (1955)
2432857.74 -241 -13.84 pg 0-.5 Wachmann (1966)
2432947.901 -239 -13.669 pe 3 Eggen (1951)
2433491.61 -227 -9.90 pg 0.5 Nikulina (1970)
2433535.293 -226 -11.210 pg 1 Chuprina (1953)
2433669.72 -223 -11.77 pg 0.5 Wachmann (1966)
2433896.09 -218 -10.37 vis 0.5 Nielsen^4 (1955)
2433941.34 -217 -10.12 vis 0.5 Dziewulski (1953)
2434166.73 -212 -9.70 pg 0.5 Wachmann (1966)
2434527.62 -204 -8.77 pg 0.5 Nikulina (1970)
2434617.73 -202 -8.65 pg 0.5 Dziewulski (1956a)
2434662.83 -201 -8.54 pg 0.5 Wachmann (1966)
2435025.01 -193 -6.32 pg 0.5 Wachmann (1966)
2435340.566 -186 -5.727 pe 1 Walraven et al. (1958)
2435387.87 -185 -5.37 pg 0.5 Wachmann (1966)
2435432.40 -184 -3.88 pg 0.5 Nikulina (1970)
2435838.11 -175 -3-13 pg 0.5 Huth (1966)
2436466.60 -161 -4.56 pg 0.5 Nikulina (1970)
2436513.77 -160 -2.39 pg 0.5 Huth (1966)
2437007.76 -149 -3.34 pg 0.5 Wachmann (1966)
2437232.486 -144 -3.588 pe 3 Mitchell et al. (1964)
2437368.90 -141 -2.16 pg 0.5 Huth (1966)
2437458.83 -139 -2.22 pg 0.5 Nikulina (1970)
2437547.5 -137 -3.5 vis 0.5 Lohsen (1964a)
2437952.641 -128 -3.349 pe 1 Williams (1966)
2438268.111 -121 -2.843 pe 3 Fernie et al. (1965)
2438450.46 -117 -0.47 pg 0.5 Huth (1966)
2438809.70 -109 -1.19 pg 0.5 Nikulina (1970)
2441511.4 -49 +0.8 vis 0.5 Cragg (1976)
2443085.325 -14 -0.069 pe 3 Fernie (1979)
2443715.004 0 -0.317 pe 3 present paper
2443759.32 +1 -1.00 vis 0.5 Busch^5 (1980)
Remarks: 1 Observer: Axel Nielsen; 2 Obs.: Moller Nicolaisen;
3 Obs.: Arthur Nielsen; 4 Obs.: Darsenius; 5 Obs.: Branzke
Table 34 O-C residuals for SV Vul
(median brightness)
Obs.Med.J.D. E O-C Type w Reference
2424370.940 -429 -37.639dvis 1 Beyer (1930)
2425139.462 -412 -34.028 vis 1 Beyer (1930)
Table 34 (cont.)
Obs.Med.J.D. E O-C Type w Reference
2425951.669 -394 -31.727 vis 1 Zakharov (1954a)
2428073.392 -347 -24.758 pg 1 Nassau, Ashbrook (1942)
2428750.349 -332 -22.723 pg 1 Dziewulski et al. (1946)
2432944.568 -239 -13.017 pe 3 Eggen (1951)
2438264.733 -121 -2.236 pe 3 Fernie et al. (1965)
2443081.677 -14 +0.268 pe 3 Fernie (1979)
2443711.761 0 +0.425 pe 3 present paper
GENERAL REMARKS
Period changes, instability of the period
From the point of view of stellar evolution, it is even more important to study
the period changes of the long period Cepheids than the short period ones. The tendency of
the long period Cepheids to undergo a considerable amount of period change has been known
for a long time (e.g. Parenago, 1956). Parenago, however, found that all the period changes
were sudden. In this part of this series on Cepheids there are 17 stars for which Parenago
also published O-C diagrams. On the basis of the newly constructed O-C diagrams for 11
stars out of the 17, the diagrams can be approximated by parabolas, thereby supporting the
existence of Cepheids with continuously changing (increasing or decreasing) period.
The statistics of the observed period changes based on the whole programme (Papers
I and II and the present paper) as well as the comparison of the theoretically calculated
evolutionary period changes with the observed changes in the period will be published in a
separate paper.
Cepheid binaries
The role of binaries in Cepheid research has seen an increase of late, since the
frequency of Cepheids with companions is estimated to be at least as high as 20 per cent
(Madore, 1977). Recent discoveries, viz. that AU Peg (Harris et al., 1979) and T Mon
(Mariska et al., 1980) are also members in binary systems, indicate that the above
mentioned frequency is really a lower limit of the true value.
Cepheids in binaries are important in several respects. They may serve as
fundamental stars in deriving Cepheid masses and in a new calibration of the
period - luminosity - colour relation. Moreover, their existence stresses the importance
of some theoretical investigations to be made concerning the pulsational behaviour of a
Cepheid in a binary system (non-radial pulsation) and their evolutionary status.
The membership of a Cepheid in a binary system causes two effects which can be
observed in the O-C diagram:
1. Periodic quasi sinusoidal variation due to the light-time effect. The present sample
contains at least four stars (RW Cam, X Cyg, SZ Cyg, T Mon) showing this kind of apparent
period change. The duplicity of zeta Gem and SV Vul is rather doubtful. The value of the
orbital period of RW Cam has been able to be determined using the O-C diagram (see p. 63):
P_{orb} = 6600 ą 300 days. In the other three cases less accurate (and considerably longer)
values for the orbital period could be determined.
2. Rejumping period (or "stepwise" O-C diagram). YZ Aur is a very clear example showing
this kind of period change (see Fig. 48). The O-C diagram of SV Per can be interpreted as
showing either a rejumping period or a light-time effect (but based on the shape of the O-C
diagram in Fig. 18, the former interpretation is preferred). In the case of AN Aur the
occurrence of the rejump can only be suspected since the period change was accompanied by
a change in the shape of the light curve - as in the case of SU Cyg (Paper I, p.77).
If both the orbital period and the amount of the apparent O-C variation can be
determined from the O-C diagram, some conclusions can be drawn as to the mass of the binary
system without using any spectroscopic data. A detailed description of these results along
with a summary of the other data on Cepheid binaries will be published in a separate paper.
Summary of the observations
The fundamental parameters of the light variations of the observed Cepheids are
summarized in Table 35. The successive columns contain the following data:
1. Name of the Cepheid
2. Period of light variation
3. Decimal logarithm of the period
4-5. The moments of the normal maximum and normal median brightnesses
Table 35 Summary
Name Period log P Norm.Max. Norm.Med. (Max.-Med.)/P Type
Hel.J.D. 2440000+
SZ Aql 17.140849 1.2340 3807.095 3806.512 0.034 I
TT Aql 13.754707 1.1385 3810.884 3810.059 0.060 I
RX Aur 11.623537 1.0653 3829.995 3828.182 0.156 I
SY Aur 10.144698 1.0062 3832.981 3830.333 0.251 I
YZ Aur 18.193212 1.2599 3816.489 3814.233 0.124 I
AN Aur 10.29056 1.0124 3799.026 3795.918 0.302 I
RW Cam 16.414812 1.2152 3840.515 3839.070 0.088 I
RW Cas 14.791548 1.1700 3830.363 3829.608 0.051 I
RY Cas 12.138888 1.0842 3826.585 3824.218 0.195 I
SZ Cas 13.637747 1.1347 3817.966 3815.594 0.174 Is
X Cyg 16.386332 1.2145 3830.274 3828.783 0.091 I
SZ Cyg 15.109642 1.1793 3760.486 3758.688 0.119 I
TX Cyg 14.7098 1.1676 3794.971 3794.235 0.050 I
VX Cyg 20.133407 1.3039 3783.660 3782.050 0.080 I
BZ Cyg 10.141932 1.0061 3774.144 3770.970 0.313 Is
CD Cyg 17.073967 1.2323 3831.224 3830.490 0.043 I
AA Gem 11.302328 1.0532 3737.679 3735.147 0.224 I
zeta Gem 10.150135 1.0065 3785.473 3782.611 0.282 Is
AP Her 10.4156 1.0177 3745.357 3743.441 0.187 II
Z Lac 10.885613 1.0369 2827.154 2825.369 0.164 I
T Mon 27.024649 1.4318 3784.184 - - I
SV Mon 15.232780 1.1828 3794.342 3793.352 0.065 I
SV Per 11.129318 1.0465 3839.246 3838.322 0.083 I
VX Per 10.88904 1.0370 3758.994 3755.650 0.307 I
SV Vul 44.994772 1.6532 3715.004 3711.761 0.072 I
derived from the observations listed in Table 3.
6. Fractional period between the moment of median brightness and that of the subsequent
light maximum (a measure of the asymmetry of the light curve)
7. Type of Cepheid
8-10. The maximum and minimum magnitudes and the amplitude in V
11-13. The corresponding quantities for B as under 8-10
14-16. The corresponding quantities for U as under 8-10
17. Name of Cepheid
of the observations
V_{max} V_{min} A_{V} B_{max} B_{min} A_{B} U_{max} U_{min} A_{U} Name
7.95m 9.24m 1.29m 8.99m 11.08m 2.09m 10.18m: 12.76m: 2.58m: SZ Aql
6.56 7.58 1.02 7.52 9.19 1.67 8.20 10.81 2.61 TT Aql
7.34 8.03 0.69 8.12 9.17 1.05 8.67 10.05 1.38 RX Aur
8.73 9.37 0.64 9.64 10.60 0.96 10.33: 11.43: 1.10: SY Aur
9.94 10.75 0.81 11.13 12.41 1.28 YZ Aur
10.20 10.80 0.60 11.33 12.24 0.91 AN Aur
8.16 9.00 0.84 9.37 10.48 1.11 10.24 11.44 1.20 RW Cam
8.55 9.75 1.20 9.45 11.36 1.91 RW Cas
9.38 10.35 0.97 10.52 11.94 1.42 RY Cas
9.61 10.03 0.42 10.94 11.59 0.65 SZ Cas
5.87 6.87 1.00 6.72 8.34 1.62 7.29 9.79 2.50 X Cyg
8.94 9.82 0.88 10.22 11.61 1.39 SZ Cyg
8.82 10.00 1.18 10.41 12.11 1.70 TX Cyg
9.57 10.54 0.97 10.98 12.54 1.56 VX Cyg
10.05 10.53 0.48 11.54 12.24 0.70 BZ Cyg
8.34 9.52 1.18 9.29 11.15 1.86 9.98 12.58 2.60 CD Cyg
9.40 10.00 0.60 10.35 11.30 0.95 AA Gem
3.66 4.17 0.51 4.35 5.10 0.75 4.87 5.94 1.07 zeta Gem
10.43 11.15 0.72 11.06 12.08 1.02 AP Her
7.89 8.82 0.93 8.73 10.18 1.45 9.33 11.23 1.90 Z Lac
5.61: 6.60 0.99: 6.49: 8.05 1.56: 7.08: 9.28 2.20: T Mon
7.63 8.78 1.15 8.43 10.21 1.78 8.79 11.26 2.47 SV Mon
8.49 9.35 0.86 9.38 10.53 1.15 SV Per
8.98 9.68 0.70 10.08 11.09 1.01 10.85 12.12 1.27 VX Per
6.74 7.76 1.02 7.86 9.53 1.67 8.66 11.20 2.54 SV Vul
Acknowledgements
I am indebted to Dr. Bela Szeidl for many valuable discussions and for his
continuous interest. I should like to thank the night assistants of the Konkoly Observatory
for participating in the observations; Mrs. E. Toth and Mr. H. Shenker are thanked for
their help in preparing the manuscript.
Budapest-Szabadsaghegy, November 22, 1980
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