COMMISSION 27 OF THE I.A.U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 154 Konkoly Observatory Budapest 1 September 1966 MINIMA OF ECLIPSING VARIABLES This report continues the one in IBVS No 129, and contains 106 observed minima of 37 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.hel E O - C n Observer (2,400,000) RT Andromedae 39318.633 +24,167 -0.014 22 C. Anderson AB Andromedae 39320.799 +12,791.5 +0.054 14 D. Williams OO Aquilae 39269.767 + 9,951.5 -0.024 13 R. Monske 39271.793 + 9,955.5 -0.026 13 R. Monske 39286.487 + 9,984.5 -0.029 11 A. Howell 39287.505 + 9,986.5 -0.024 12 A. Howell 39287.755 + 9,987 -0.028 12 R. Monske 39288.765 + 9,986 -0.031 13 R. Monske 39289.755 + 9,991 -0.024 14 R. Monske 39291.805 + 9,995 -0.032 17 D. Williams 39297.636 +10,006.5 -0.029 10 R. Monske 39298.652 +10,008.5 -0.027 12 R. Monske 39299.665 +10,010.5 -0.027 14 R. Monske 39300.679 +10,012.5 -0.027 14 R. Monske 39317.661 +10,046 -0.023 14 R. Monske 39318.672 +10,048 -0.025 11 R. Monske 39322.725 +10,056 -0.027 12 R. Monske 39328.809 +10,068 -0.024 11 R. Monske V342 Aquilae (1 39328.751 + 1,090 +0.004 31 R. Monske V346 Aquilae 39300.720 + 7,205 -0.026 17 R. Monske AR Aurigae 49183.616: + 3,009 -0.012 13 R. Monske Y Camelopardalis 39183.612 + 4,462 -0.025 18 R. Monske SV Camelopardalis 39273.425 +11,779 -0.015 13 A. Howell 39290.621 +11,808 -0.018 11 F. Sanner 39291.796 +11,810 -0.029 11 F. Sanner 39294.769 +11,815 -0.021 13 F. Sanner AL Camelopardalis (2 39260.493 + 9,673 -0.080 21 A. Howell 39280.411 + 9,688 -0.087 11 A. Howell RZ Cassiopeiae 39052.7928 +18,153 -0.0382 89pe A. Stokes 39186.656 +18,265 -0.043 15 R. Monske 39198.609 +18,275 -0.043 15 R. Monske 39198.614: +18,275 -0.038 23 D. Ducas 39259.567 +18,326 -0.043 9 A. Howell 39315.750: +18,373 -0.036 14 C. Anderson 39321.722 +18,378 -0.041 16 R. Swanberg 39327.695 +18,383 -0.044 23 D. Lucas 39327.699 +18,383 -0.040 12 J. Ashbrook (3 AB Cassiopeiae 39183.819 +10,021 +0.059 19 R. Monske 39186.550 +10,023 +0.057 14 R. Monske 39201.593 +10,034 +0.064 21 R. Monske XX Cephei 39183.520 + 6,027 -0.045 11 R. Monske EG Cephei (4 39291.800 +22,699 +0.008 18 D. Williams Y Cygni 39299.762 + 9,934 +0.008 (5 21 D. Friedman ZZ Cygni 39287.493 +28,873 -0.011 13 A. Howell V 477 Cygni 39288.751 + 2,745 -0.052 8 D. Williams 39295.793 + 2,748 -0.051 11 D. Williams Z Draconis 39192.578 + 4,364 +0.013 12 C. Ricker 39200.717 + 4,370 +0.007 13 R. Monske 39200.724 + 4,370 +0.014 11 T. Cragg 39230.585 + 4,392 +0.012 22 D. Lucas 39234.656 + 4,395 +0.010 12 R. Monske 39272.664 + 4,423 +0.010 20 R. Monske 39291.669 + 4,437 +0.011 15 R. Monske 39295.740 + 4,440 +0.010 10 T. Cragg 39299.813 + 4,443 +0.010 15 R. Monske 39314.743 + 4,454 +0.009 22 D. Lucas AI Draconis 39245.621: +12,185 +0.007 18 L. Hazel 39262.417 +12,199 +0.020 12 A. Howell 39269.604 +12,205 +0.014 19 J. Ashbrook 39275.610 +12,210 +0.026 22 D. Friedman 39288.782 +12,221 +0.011 15 R. Monske 39294.782 +12,226 +0.017 17 R. Monske 39300.773 +12,231 +0.043 15 R. Monske 39318.757 +12,246 +0.016 16 R. Monske SZ Herculis (6 39245.573 + 2,590 +0.010 17 A. Howell 39259.482 + 2,607 +0.012 21 A. Howell 39286.477 + 2,640 +0.010 14 A. Howell 39294.657 + 2,650 +0.009 15 R. Monske 39294.661 + 2,650 +0.013 19 D. Lucas 39303.658 + 2,661 +0.011 16 R. Monske 39303.662 + 2,661 +0.015 21 D. Lucas 39321.659 + 2,683 +0.014 11 W. Hampton 39330.656 + 2,694 +0.012 12 W. Lowder SW Lacertae 39322.789 +49,732.5 +0.041 15 R. Swanberg 39323.748 +49,735.5 +0.038 12 R. Swanberg 39330.802 +49,757.5 +0.036 15 R. Swanberg VX Lacertae 39291.801 + 4,716 -0.025 16 D. Williams CM Lacertae 39295.788 + 7,646 0.000 12 D. Williams Y Leonis 39199.567 + 3,268 +0.032 16 R. Monske 39231.603 + 3,287 +0.033 19 R. Monske 39231.605 + 3,287 +0.035 21 L. Hazel UV Leonis 39201.638 +10,342 -0.002 13 F. Sanner 39240.638 +10,407 -0.007 14 D. Williams T Leonis Minoris 39212.651 + 5,085 -0.034 17 L. Hazel 39230.771 + 5,091 -0.034 12 T. Cragg SS Librae 39287.706 +13,238 +0.028 14 R. Monske 39323.641 +13,263 +0.013 16 R. Monske Delta Librae 39269.494: + 2,068 -0.015 6 A. Howell FL Lyrae 39238.753: + 2,471 -0.001 21 L. Hazel 39284.492 + 2,492 -0.003 14 A. Howell 39299.749: + 2,499 +0.007 14 R. Monske 39299.753 + 2,499 +0.011 22 D. Friedman 39310.625 + 2,504 -0.008 21 J. Ashbrook 39323.702 + 2,510 0.000 18 R. Monske Beta Lyrae 39276.4 + 3,149 -0.1 (7 7 A. Howell U Ophiuchi 39269.449 +18,475.5 +0.002 8 A. Howell 39288.731 +18,487 -0.006 12 D. Williams 39300.475 +18,494 -0.003 13 A. Howell BV 544 Ophiuchi 38937.772 (8 +19,821 -0.006 9 D. Williams RT Persei 39199.546 + 7,077 -0.018 12 R. Monske U Sagittae 39320.798 + 6,564 +0.004 15 D. Williams BV 312 Tauri 39194.338 (9 + 6,591 -0.001 9 A. Howell X Trianguli 39198.548 + 4,635 +0.024 14 R. Monske W Ursae Majoris 39229.775 +14,208 +0.006 6 T. Cragg 39230.777 +14,211 +0.008 10 T. Cragg TX Ursae Majoris 39245.394 + 7,449 -0.041 11 A. Howell \1/ O - C was computed from elements given in IBVS No. 92. \2/ O - C's were computed from elements in the 1960 supplement to the General Catalogue of Variable Stars \3/ The time of minimum was determined by fitting the observations to a mean light curve \4/ O - C was computed from the elements in the 1960 supplement to the General Catalogue of Variable Stars \5/ Elements for apsidal motion were used in computing O - C \6/ O - C's were computed from the elements in Sky and Tele., May 1963, page 277. \7/ Quadratic elements were used in computing O - C \8/ The minimum at JD 38936.772 reported in IBVS No. 119 is wrong; substitute the one given in this report. \9/ O - C's computed from elements given in Sky and Tele., November, 1963, page 264. This work is sponsored by the American Association of Variable Star Observers, with David B. Williams as program coordinator. All reductions were made by the writer with Joseph Ashbrook. L. J. ROBINSON "Sky and Telescope" 49 Bay State Rd. Cambridge, Mass. USA