COMMISSION 27 OF THE I.A.U. INFORMATION BULLETIN ON VARIABLE STARS Number 1249 Konkoly Observatory Budapest 1977 March 14 MINIMA OF ECLIPSING VARIABLES We report below the times of minimum light for eclipsing variable stars. Table 1 Photoelectric Minima. Star JD hel. Er n f ap comp. Delta m Notes Obs. 2440000+ min. SV Cam 2836.5905 .001d 26 v 90 001047 1.25 1), 2) DRS/ADM SV Cam 2852.601 .002 19 none 30 001047 1.01 1) ADM SV Cam 2855.5658 .001 27 v 30 001047 1.25 1), 3) ADM R CMa 2820.5936 .001 10 v 90 152834 0.98 DRS/ADM YY Gem 2829.634 .002 28 v 90 060198 8.22: DRS/ADM U Peg 3021.6134 .001 17 v 90 -- -- DRS beta Per 3066.6630 .001 20 v 30 056047 -1.47 5) ADM beta Per 3066.6622 .001 20 B 30 056047 -1.49 5) ADM beta Per 3089.6003 .001 20 V 30 056047 -1.46 5) ADM beta Per 3089.6008 .001 22 B 30 056047 -1.49 5) ADM lambda Tau 3113.6874 .005 24 V 30 111696 -0.39 5), 6) ADM lambda Tau 3113.6909 .005 24 B 30 111696 -0.41 5), 6) ADM W UMa 2829.7280 .001 19 v 90 027340 -- DRS/ADM W UMa 2863.5915 .001 22 v 30 027340 1.93: ADM TX UMa 2844.694 .002 16 v 30 -- -- ADM AG Vir 2892.6620 .001 27 v 30 099924 1.39 4) DRS/ADM The observations were made with a UBV photometer, containing a 1P21 phototube, attached to reflecting telescopes of 30 and 90 cm aperture. The time of minimum was calculated by the tracing paper method. Er=the maximum error for the time of minimum; n=number of observations; f=filter; ap=aperture of the telescope in cm; comp=SAO catalog number of the comparison star; delta m min.=m (variable) minus m (comparison) at mid-eclipse in the instrumental magnitude system, except where noted. Notes: 1) Ascending branch steeper than descending branch. 2) Duration of constant light = 28 minutes. 3) Duration of constant light = 35 minutes. 4) Duration of constant light = 52 minutes. 5) Observations transformed to the standard system. 6) Observations obtained on JD2443113 and 2443117. Table 2 Visual Minima. JD hel. 2,440,000+ n m Epoch O-C Observer WZ Andromedae, sigma = .006d 3024.654 16 1 11427 -d.018 Krobusek XZ Andromedae, sigma = .003d 2665.550 6 1 2586 -.021 Mallama 2684.550 8 1 2600 -.024 Mallama 2707.626 14 1 2617 -.022 Mallama 2722.558 11 1 2628 -.020 Mallama AB Andromedae, sigma = .006d 2709.588 11 1 19886 +.021 Krobusek 3044.623 7 1 20895.5 +.012 Krobusek CX Aquarii, sigma = .004d 2665.589 8 1 11173 +.010 Mallama OO Aquilae, sigma = .006d 2601.654 7 1 17120 -.028 Krobusek 2602.659 8 1 17122 -.037 Krobusek 2603.670 8 1 17124 -.040 Krobusek 2709.600 7 1 17333 -.029 Krobusek 3008.598 9 1 17923 -.040 Krobusek 3010.629 8 1 17927 -.036 Krobusek HP Aurigae, sigma = ---- 2683.78 5 1 ----- --- Mallama RX Cassiopeiae, sigma= .5d 2706.5 6 2 578.5 +3.0 Mallama 2883.7 5 2 584 +2.4 Mallama RZ Cassiopeiae, sigma = .004d 2412.644 15 1 4408 +.006 Mallama 2412.650 18 1 4408 +.011 Krobusek 2510.655 13 1 4490 +.006 Krobusek SX Cassiopeiae, sigma = .3d 2739.2: 5 1 240 -.0.2: Mallama U Cephei, sigma = .002d 2392.583 19 1 1645 +.027 Krobusek 2741.617 11 2 1785 +.037 Mallama EG Cephei, sigma = .003d 2598.739 12 1 28771 +.013 Krobusek 2664.641 15 1 28892 +.016 Mallama EK Cephei, sigma = .006d 2447.545 14 1 778 +.002 Krobusek TW Ceti, sigma = .004d 2392.545 9 1 37039 -.021 Krobusek RW Comae Berenices, sigma = .004d 2860.716 12 1 41375.5 -.C43 Krobusek 2861.676 9 1 41379.5 -.032 Krobusek 2920.643 13 1 41628 -.046 Krobusek 2922.665 15 1 41636.5 -.041 Krobusek 2925.638 10 1 41649 -.035 Krobusek W Corvi, sigma = .01d 2510.637 8 1 37748 -.005 Krobusek 2860.683 10 1 38650 -.008 Krobusek 2861.662 9 1 38652.5 +.001 Krobusek V Crateris, sigma = .005d 2489.690 19 1 21408 +.021 Krobusek 2861.765 8 2 21938 +.018 Krobusek ZZ Cygni, sigma = .003d 2599.672 10 1 34142 -.029 Krobusek 2699.617 8 1 34301 -.034 Mallama 2968.666 9 1 34729 -.034 Krobusek 2985.642 10 1 34756 -.031 Krobusek 2990.669 10 1 34764 -.033 Krobusek TT Delphini, sigma = .005d 2665.645 11 1 1535 +.048 Mallama TY Delphini, sigma = .006d 2985.650 11 1 12564 +.007 Krobusek 3010.661 15 1 12585 +.004 Krobusek Z Draconis, sigma = .002d 2576.674 11 1 6857 .000 Krobusek 2595.678 12 1 6870 .000 Krobusek RZ Draconis, sigma = .005d 2412.553 8 1 23533 -.015 Krobusek 2412.556 9 1 23533 -.012 Mallama 2576.715 6 1 23831 -.014 Krobusek 2608.670 9 1 23889 -.010 Krobusek 2922.662 13 1 24459 -.018 Krobusek 3008.599 10 1 24615 -.017 Krobusek TW Draconis, sigma = .003d 2707.600 14 1 3142 -.038 Mallama AI Draconis, sigma = .005d 2598.704 13 1 2959 -.003 Krobusek 2664.651 16 1 3009 +.D09 Mallama 3020.692 19 1 3306 +.002 Krobusek SZ Herculis, sigma = .003d 2577.686 11 1 9278 +.027 Krobusek 2964.644 11 1 9751 +.026 Krobusek VX Lacertae, sigma = .005d 2664.634 17 1 7855 -.060 Mallama 2707.617 14 1 7895 -.057 Mallama CM Lacertae, sigma = .003d 2665.632 13 1 9746 -.008 Mallama TZ Lyrae, sigma = .005d 2596.651 13 1 41464 +.021 Krobusek 2696.588 6 1 41653 +.010 Krobusek 2964.715 11 1 42160 +.024 Krobusek 2990.637 15 1 42209 +.033 Krobusek 3008.609 10 1 42243 +.025 Krobusek 3044.562 10 1 42311 +.018 Krobusek U Ophiuchi, sigma = .01d 2990.641 12 1 20694 +,002 Krobusek ER Orionis, sigma = .007d 2433.625 10 1 13993.5 -.021 Krobusek 2446.540 9 1 14024 -.019 Krobusek 2751.593 8 1 14744.5 -.027 Krobusek U Pegasi, sigma = .004d 3020.679 13 1 17367.5 -.015 Krobusek 3024.612 10 2 17378 -.017 Krobusek RT Persei, sigma = .003d 2684.634 7 1 21346 -.060 Mallama 2842.625 7 1 21532 -.059 Krobusek IZ Persei, sigma = .01d 2722.682 14 1 4651 +.011 Mallama beta Persei, sigma = .01d 2699.638 12 1 1123 -.088 Mallama 2722.590 10 1 1131 -.075 Mallama 2765.600 10 1 1146 -.076 Mallama 3089.597 18 1 1259 -.094 Krobusek RZ Scuti, sigma = .07d 2684.61: 4 3 372 +.14: Mallama BS Scuti, sigma = .003d 2689.594 12 2 4692 -.046 Mallama RZ Tauri, sigma = .01d 2844.643 6 1 12433 +.003 Krobusek HU Tauri, sigma = .01d 2786.715 20 1 8338 +.026 Krobusek X Trianguli, sigma = .003d 2745.606 11 1 5325 -.036 Mallama 3052.608 11 1 5641 -.038 Krobusek XZ Ursae Majoris, sigma = .005d 2925.625 14 1 13532 -.072 Krobusek W Ursae Minoris, sigma = .01d 2412.649 12 1 5264 -.006 Krobusek RU Ursae Minoris, sigma = .007d 2844.612 18 1 31220 -.008 Krobusek AZ Virginis, sigma = .005d 2489.750 8 1 47686 .038 Krobusek 2540.624 9 1 47857 -.036 Krobusek Z Vulpeculae, sigma = .01d 2716.718 14 2 7031 +.016 Mallama For each minimum, both the descending and ascending branch of the light curve was observed. The time of minimum was measured by the tracing paper method. After the star name, the standard deviation, sigma, expected for a single primary minimum was obtained visually for a star of that light curve is given. These standard deviations are calculated from studies by Mallama, (1974a, 1974b). JD hel=heliocentric Julian date of minimum light; n = number of visual estimates contributing to the light curve; m = number of different minima used in the light curve. Epoch and O-C refer to the linear elements in GCVS 1969. Table 3 Photographic Minima of BF Virginis. JD 2414512.59 JD 2416595.67 JD 2415902.59 JD 2418524.45 JD 2416242.68 One of us (P.A.P.) searched 200 photographic plates in the Harvard collection to identify times when the variable was faint between 1891 and 1937. The results tend to support the suggestion by Mallama and Witt (1976) that a large period change may have occurred before 1930, but more data are needed to verify this. Acknowledgements ADM and DRS wish to thank C. McCracken of Goddard Space Flight Center for use of the 90 cm telescope and photoelectric equipment. ADM acknowledges the help of M. Liller in coordinating the search of the Harvard plate collection. We wish to thank B.L. Krobusek for careful preparation of the manuscript. ANTHONY D. MALLAMA and DAVID R. SKILLMAN Computer Sciences Corp., Silver Spring, MD PHILIP A. PINTO Hartsdale, NY BRUCE A. KROBUSEK Kent State University, Kent, OH References: Mallama, A.D. (1979a) JAAVSO, 3, 11 [BIBCODE 1974JAVSO...3...11M ] Mallama, A.D. (1974b) JAAVSO, 3, 49 [BIBCODE 1974JAVSO...3...49M ] Mallama, A.D. and Witt, A.N. (1975) Acta Astr. 26, 253 [BIBCODE 1976AcA....26..253M ]