| COMMUNICATIONS | MITTEIL UNGEN |
| FROM THE | DER |
| KONKOLY OBSERVATORY | ST ERNWARTE |
| OF THE | DER UNGARISCHEN AKADEMIE |
| HUNGARIAN ACADEMY OF SCIENCES | DER WISSENSCHAFTEN |
4403 photographic observations obtained in the years 1943-1950, 2611 white
light observations from the years 1950-1957, altogether 31794 UBV observations collected in the years 1958-1981 and 7135 observations made in the Strömgren
uvby and H{beta} wide/narrow band photometric system between 1990 and 1993 are
published.
1525 Budapest, P.O. Box 67, Hungary
2Dept. Astronomy and Astrophysics, Villanova University,
Villanova, PA 19085, U.S.A.
INTRODUCTION
Some sixty years ago Prof. L. Detre initiated the long term monitoring of
RR Lyrae (HD 182989) at Konkoly Observatory resulting in the discovery of a
four-year cycle in its 40-day Blazhko-period (Detre & Szeidl, 1973).
In order to solve the still enigmatic problem of the Blazhko effect we deem
it important to publish all the observations of RR Lyr available to us. We
present here photographic observations from the years 1943-1950, photoelectric
observations in white light made in 1950-1957, photoelectric UBV observations
obtained in 1958-1981 and Strömgren uvby and H{beta} observations made from
1990 through 1993.
SUMMARY OF PHOTOMETRY OF RR LYRAE
Photographic photometry was carried out at Konkoly Observatory, Budapest with
the 16 cm astrograph using Eastman 40 plates with 30 s exposure time from 16
May 1943 (JD 2430861) through 21 June 1950 (JD 2433454). The comparison stars
and their magnitudes used in measuring these plates are given in Detre's (1943)
paper. During 96 nights about 8800 observations were obtained and by pairs
averaged. Table 1 presents 4403 photographic observations. The time of
observations are converted to HJD.
Table 1.099-t1.txt
The photoelectric photometry was commenced at Konkoly Observatory in 1950.
At first the photometry was conducted with the observatory's 60 cm telescope
without using any filter. In 1950-1953 an RCA 931A, from 1954 an RCA 1P21
multiplier tube was employed in the photometer. Although these observations
are on an indefinite photometric system they well supplement Walraven's (1949)
photoelectric observations. The observations published here were made between
12 July 1950 (JD 2433475) and 30 October 1957 (JD 2436142). The comparison
star used was HD 183125. (The same one was used by Walraven, too.) In Table 2,
2611 white light observations obtained during 45 nights are given.
Table 2.099-t2.txt
The UBV photoelectric observations were carried out using the 60 cm Newton
telescope at Budapest from 26 July 1958 (JD 2436411) through 26 September
1981 (JD 2444874). Since RR Lyrae is fairly bright the mirror of the telescope
usually had to be diaphragmed to 35-50 cm depending on the sky transparency.
The mirror of the telescope was first aluminized in 1963. Before 1963 an
RCA 1P21 multiplier was used with Schott filters UG1 in U, BG12+GG13 in B and GG11 in V; and thereafter an EMI 9052B tube with the same filter combination as in the previous years.
The comparison star used to the UBV observations was HD 183125 (A2). Tie-in
observations made on several nights yielded for this star: V=7.999±.007,
B-V=+0.289±.006, U-B=+0.077±.015. The constancy of the comparison star was checked against the star HD 182487 (V=7.009, B-V=+0.020, U-B=-0.119,
Preston et al., 1965).
The observations of the variable were reduced in the usual way. The UT times
have been converted to HJD and the differential magnitudes have been corrected
for atmospheric extinction. (These corrections were mostly negligible since
the comparison is very close to the variable, only about half a degree away.)
The observations have been transformed into the UBV system in the traditional
way (see e.g. Hardie, 1962).
In Tables 3 and 4 we present 14977 differential V and 15331 differential B
magnitudes collected on 446 nights. In Table 5, 1486 differential U magnitudes
obtained on 38 nights are given. The differential magnitudes are given in the
sense variable minus comparison.
Table 3.099-t3.txt
Table 4.099-t4.txt
Table 5.099-t5.txt
Differential photoelectric photometry of RR Lyr was conducted from 10 September
1990 through 22 June 1993 with the 0.8 m Automatic Photoelectric Telescopes
(APT) at Fairborn Observatory, Mt. Hopkins, Arizona. These APTs are nearly
identical and equipped with filter sets closely matched to the Strömgren
uvby and H beta wide/narrow band photometric systems. The T5 APT was used for
the observations made up to October 1991. Intensive photometry of RR Lyr
was obtained during 1 May - 22 June UT 1993 using chiefly the T6 APT. The
characteristics of the T6 APT (later acquired by the University of Vienna
and renamed `Wolfgang') is given by Strassmeier et al. (1997). The T5 APT is
similar and has been operated by the Four College Consortium and is known
as the FCC 0.8 m APT.
The comparison star was HD 182487 (V=7.01, B-V=+0.02; A0 (V)) and HD 182694
(=HR 7382; V=5.84, B-V=+0.92; G2 IIIa) served as the check star. The usual
sky-comparison-variable/check-comparison-sky observing sequence was used
and integration times of 10 s were used. Observations were obtained on 63
nights and given in the sense of differential magnitude, {Delta}mag variable
minus comparison star (V-C).
The observations were reduced in the usual way with UT times converted to
HJD and the differential magnitudes corrected for atmospheric extinction.
Because of the close angular proximity of the variable, comparison and
check stars, the differential extinction corrections were always very small.
In Tables 6, 7, 8, 9, 10 and 11, 1199 {Delta}y, 1196 {Delta}b, 1176 {Delta}v, 1166 {Delta}u, 1199 H{beta} narrow band and 1199 H{beta} wide band observations are given,
respectively.
Table 6.099-t6.txt
Table 7.099-t7.txt
Table 8.099-t8.txt
Table 9.099-t9.txt
Table 10.099-t10.txt
Table 11.099-t11.txt
ACKNOWLEDGEMENTS
We are grateful to the late director of the Konkoly Observatory, Prof. L.
Detre who made the early photoelectric observations and significantly
contributed to the UBV observations. Thanks are also due to Dr. I. Guman
who made most of the photographic exposures and to our colleagues, Prof. B.
Balázs, Dr. Katalin Barlai, Dr. G. Kovács, Mr. M. Lovas and Dr. L. Patkós
who obtained some of the observations. Mr. J. Bartus helped us with the data
handling. The research grant from OTKA No. T-015759 is also acknowledged.
Detre, L. 1943, Mitteilungen d. Sternwarte Budapest-Svábhegy Nr. 17. CoKon 17
Detre, L. and Szeidl, B. 1973, IBVS No. 764 IBVS 764
Hardie, R.H. 1962, Photoelectric Reduction in: Astronomical Techniques,
Stars and
Stellar Systems, Vol. 2, Ed. W.A. Hiltner, p. 178
Preston, G.W., Smak, J. and Paczynski, B. 1965, ApJS 12, 99
Strassmeier, K.G., Boyd, L.J., Epand, D.H. and Granzer, Th. 1997, PASP 109, 697
Walraven, Th. 1949, BAN 11, 17