COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 2321 Konkoly Observatory Budapest 22 April 1983 HU ISSN 0374 - 0676 EPOCHS OF MINIMUM LIGHT FOR SEVERAL ECLIPSING BINARIES Presented here are times of minimum light for several eclipsing binaries observed with the 41 cm reflector of the Morgan-Monroe Station of the Goethe Link Observatory. All observations were made with Johnson UBV filters and a 1P21 Photomultiplier tube cooled with dry ice. For each eclipse either the Hertzsprung method or the method of bisection of chords was used, and are indicated by their abreviations in the table. The bisection of chords method was used when the observations were of poor quality and hence these times of minimum light should receive lower weight. The tabulated results Table ---------------------------------------------------- Star Hel. J.D. Type Method (O-C) 2440000+ ---------------------------------------------------- BX And 3033.8307 I Hertz. 0.0032 3034.7460 II Bis. 0.0034 3098.8043 II Bis. -0.0004 3099.7228 I Hertz. 0.0029 U Cep 5229.6853(V) I Hertz. 0.0011 .6866(B) I Hertz. 0.0024 .6874(U) I Hertz. 0.0032 5259.6035(V) I Hertz. 0.0027 .6034(B) I Hertz. 0.0026 .6035(U) I Hertz. 0.0027 5264.5910(V) I Hertz. 0.0041 .5909(B) I Hertz. 0.0040 .5909(U) I Hertz. 0.0040 V366 Cyg 5242.5866 I Bis. -0.0419 TZ Eri 5241.8592 I Hertz. 0.0153 SW Lac 4493.7540 I Hertz. 0.0000 RW Tau 5221.8143 I Hertz. -0.0008 5257.8086 I Hertz. -0.0014 ---------------------------------------------------- are the average of the three filters. The one exception to this is U Cep where the times of minimum light are known to be a function of wavelength due to circumstellar material (Crawford and Olson, 1979). The residuals were determined using light elements from the following sources: BX And (Chou, 1959), U Cep (Olson, et al., 1981), V366 Cyg (Houten, 1956), TZ Eri (Perova, 1975), SW Lac (Faulkner and Bookmyer, 1978), RW Tau (Olson, 1982). DANNY R. FAULKNER and RONALD H. KAITCHUCK Astronomy Department Swain Hall West 319 Indiana University Bloomington, IN 47405 U.S.A. References: Chou, K.C. 1959, A.J. 64, 468. [BIBCODE 1959AJ.....64..468C ] Crawford, R.C., and Olson, E.C. 1979, Pub. Astr. Soc. Pac. 91, 413. [BIBCODE 1979PASP...91..413C ] Faulkner, D.R., and Bookmyer, B.B. 1978, Inf. Bull. Var. Stars No. 1503. Houten, C.J. Van 1956, Bull. Astr. Inst. Neth. 13, 71. [BIBCODE 1956BAN....13...71V ] Olson, E.C. 1982, Ap. J. 259, 702. [BIBCODE 1982ApJ...259..702O ] Olson, E.C., Crawford, R.C., Hall, D.S., Louth, H., Markworth, N.L. Piirola, V. 1981, Pub. Astr. Soc. Pac. 93, 464. [BIBCODE 1981PASP...93..464O ] Perova, N.B. 1975, Variable Stars 20, 197. [BIBCODE 1975PZ.....20..197P ]