COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 129 Konkoly Observatory Budapest 28 March 1966 MINIMA OF ECLIPSING VARIABLES This report continues the one in IBVS No. 119, and contains 84 observed minima of 20 eclipsing variable stars. All are visual timings reduced by the tracing-paper method, except where noted. Linear elements in the 1958 General Catalogue of Variable Stars were used to compute O - C' s unless otherwise specified. The number of estimates used for each minimum is given under n. J. D. E O - C n Observer (2,400,000) RT Andromedae 39069.567 +23,771 -0.023 13 R. Monske 39074.600 +23,779 -0.021 12 R. Monske 39079.632 +23,787 -0.021 13 R. Monske 39084.667 +23,795 -0.017 12 R. Monske 39084.668 +23,795 -0.016 15 R. Swanberg 39089.695 +23,803 -0.021 13 R. Monske 39113.597 +23,841 -0.018 8 M. Baldwin 39130.572 +23,868 -0.024 16 R. Monske 39135.596 +23,876 -0.032 19 D. Friedman XZ Andromedae 39007.660 +4,512 +0.050 15 W. Lowder 39079.594 +4,565 +0.048 16 R. Monske 39079.597 +4,565 +0.051 18 L. Hazel 39083.668 +4,568 +0.050 22 M. Baldwin 39091.811 +4,574 +0.050 20 M. Baldwin 39102.668 +4,582 +0.049 19 M. Baldwin 39117.598 +4,593 +0.049 13 R. Monske 39136.600 +4,600 +0.049 17 M. Baldwin 39140.672 +4,610 +0.049 13 M. Baldwin 39155.603 +4,621 +0.050 19 M. Baldwin E O - C n Observer J. D. (2,400,000) WW Aurigae 39092.709 +2,308.5 +0.011 17 M. Baldwin 39140.672 +2,327.5 -0.001 14 M. Baldwin AR Aurigae 39092.678 +2,987 +0.013 16 M. Baldwin Y Camelopardalis 39140.648 +4,449 -0.017 14 M. Baldwin 39173.702 +4,459 -0.018 30 L. Hazel SV Camelopardalis 39083.644 +11,459 -0.013 9 M. Baldwin 39096.697 +11,481 -0.007 12 F. Sanner 39102.625 +11,491 -0.010 11 M. Baldwin 39137.607 +11,550 -0.019 13 F. Sanner 39140.574 +11,555 -0.018 11 M. Baldwin RZ Cassiopeiae 39070.722 +18,168 -0.038 14 R. Monske 39094.627 +18,188 -0.038 15 M. Baldwin 39112.557 +18,203 -0.037 13 M. Baldwin 39143.631 +18,229 -0.041 15 R. Swanberg 39155.584 +18,239 -0.039 14 M. Baldwin 39180.676 +18,260 -0.047 17 J. Ashbrook 3) TV Cassiopeiae 39117.523 +10,482 +0.003 19 R. Monske AB Cassiopeiae 39086.773 + 9,950 +0.061 21 M. Baldwin 39093.608 + 9,955 +0.061 15 M. Baldwin U Cephei 39086.776 +12,514 +0.751 26 M. Baldwin 39091.764 +12,516 +0.754 29 M. Baldwin 39144.116 +12,537 +0.756 26 M. Baldwin XX Cephei 39087.650 + 5,986 -0.084 15 M. Baldwin 39094.664 + 5,989 -0.082 13 M. Baldwin J. D. (2,400,000) E O - C n Observer ZZ Cephei 39035.826 + 5,431 0.000 16 M. Baldwin 39093.660 + 5,458 +0.006 17 M. Baldwin Z Draconis 39086,697 + 4,286 +0.012 14 M. Baldwin 39139.636 + 4,325 +0.011 15 M. Baldwin SW Lacertae 39023.389 +48,799 +0.029 13 G. Comello 39023.546 +48,799.5 +0.025 14 G. Comello 39069.737 +48,943.5 +0.033 13 R. Monske 39070.695 +48,946.5 +0.029 13 R. Monske 39074.545 +48,958.5 +0.029 13 R. Monske 39079.675 +48,974.5 +0.029 12 R. Monske 39083.524 +48,986.5 +0.030 13 R. Monske 39089.619 +49,005.5 +0.031 12 R. Monske 39096.677 +49,027.5 +0.033 13 R. Monske 39112.712 +49,077.5 +0.033 15 R. Swanberg 39116.562 +49,089.5 +0.034 14 R. Monske 39117.517 +49,092.5 +0.027 14 R. Monske Y Leonis 39177.646 + 3,255 +0.030 11 C. Ricker RT Persei 39079.791 + 6,936 -0.007 13 R. Monske 39091.675 + 6,950 -0.015 14 M. Baldwin 39120.556 + 6,984 -0.013 17 D. Williams 39148.587 + 7,017 -0.013 20 M. Baldwin 39154.532 + 7,024 -0.013 15 R. Monske 39165.576 + 7,037 -0.012 13 R. Monske ST Persei 39091.712 + 3,611 -0.065 25 M. Baldwin Beta Persei 2) 39069.611 + 385 -0.009 25 R. Monske 39089.690 + 392 -0.001 17 R. Monske RW Tauri 39102.679 + 1,690 +0.005 23 M. Baldwin J. D. E O - C n Observer (2,400,000) X Trianguli 39091.681 +4,525 +0.025 14 M. Baldwin 39092.655 +4,526 +0.027 15 M. Baldwin 39093.622 +4,527 +0.023 7 M. Baldwin 39093.622 +4,527 +0.023 20 R. Monske 39094.594 +4,528 +0.023 18 M. Baldwin 39128.599 +4,563 +0.025 18 M. Baldwin 39129.570 +4,564 +0.024 23 R. Monske 39129.571 +4,564 +0.025 18 M. Baldwin 39130.540 +4,565 +0.023 20 L. Hazel 39130.542 +4,565 +0.025 21 R. Monske 39163.564 +4,599 +0.015 13 L. Hazel 39165.507 +4,601 +0.015 16 L. Hazel 39165.519 +4,601 +0.027 15 R. Monske 39166.495 +4,602 +0.031 13 R. Monske 1). The time of minimum was determined by fitting the observations to a mean light curve. 2). O - C's were computed from the elements in Sky and Tele., 27, 5, 316. 3). Some of the minima reported by J. Ashbrook in IBVS No. 119 were determined with a mean light curve. This work is sponsored by the American Association of Variable Star Observers, with David B. Villiams as program coordinator. The reductions are made by the writer with Joseph Ashbrook, except in some cases which were checked. We would like to acknowledge the work of Dr. R. Szafraniec (Cracow Observatory) and of Dr. V. P. Zessevich (Odessa Astronomical Observatory). Their extensive visual observations of eclipsing variable stars has provided much guidance for this program. L. J. ROBINSON "Sky and Telescope" 48 Bay State Rd. Cambridge, Mass. USA