COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 954 Konkoly Observatory Budapest 1975 January 10 MINIMA OF ECLIPSING VARIABLES The list below contains visual minima of eclipsing variables. For each minimum both the descending and ascending branch of light curve was observed. The time of minimum was measured from each light curve by the tracing paper method. After each star name the standard deviation, {sigma}, expected for a single visual minimum of a star with that light curve is given. These standard deviations are calculated from studies by Mallama (1974, JAAVSO, 3, 11 and 1974, JAAVSO, submitted). Column one lists the heliocentric time of minimum. In column two is the number of visual estimates contributing to the light curve. Columns three and four give the epoch and O-C according to the linear elements of GCVS 1969, not including the 1971 supplement. The last column lists the visual observer. JD hel. (2442000+) n epoch O-C Observer WZ Andromedae, sigma=d.006 359.603 12 10471 -d.016 Krobusek CX Aquarii, sigma=d.004, 309.764 10 10533 +.016 Krobusek 343.673 8 10594 +.010 Krobusek OO Aquilae, sigma=d.006 203.681 10 16388 -.029 Krobusek 232.709 7 16392 -.028 Mallama 232.709 8 16392 -.028 Krobusek 234.721 9 16396 -.043 Krobusek 234.724 9 16396 -.040 Mallama 235.744 8 16398 -.033 Mallama 235.750 9 16398 -.027 Krobusek 245.641 8 16417.5 -.019 Krobusek 247.644 7 16421.5 -.043 Krobusek 248.667 8 16423.5 -.034 Krobusek 250.699 11 16427.5 -.029 Krobusek 256.786 9 16439.5 -.023 Krobusek 264.635 8 16455 -.030 Krobusek 265.647 8 16457 -.031 Krobusek 266.638 7 16459 -.054 Krobusek 324.687 13 16573.5 -.033 Krobusek 337.609 8 16599 -.034 Krobusek RZ Cassiopeiae, sigma=d.004 235.738 18 4260 -.004 Krobusek 235.743 23 4260 +.001 Mallama 265.626 13 4285 +.003 Krobusek 314.635 16 4326 +.007 Krobusek EK Cephei, sigma=d.006 314.713 18 748 +.004 Krobusek RZ Draconis, sigma=d.005 229.668 10 23201 -.009 Krobusek 234.619 9 23210 -.016 Krobusek 235.723 9 23212 -.013 Mallama 240.682 10 23221 -.013 Krobusek 245.629 8 23230 -.023 Krobusek 253.625 10 23244.5 -.015 Krobusek 272.638 9 23279 -.007 Krobusek 337.630 11 23397 -.019 Krobusek JD hel (2442000+) n epoch O-C Observer RZ Draconis, sigma=d.005 342.595 8 23406 -d.012 Krobusek 359.661 7 23437 -.023 Krobusek AI Draconis, sigma=d.005 230.663 10 2647 -.009 Krobusek 236.670 13 2652 +.004 Krobusek 266.635 16 2677 -.001 Krobusek 272.636 12 2682 +.006 Krobusek 296.616 11 2702 +.010 Krobusek SW Lacertae, sigma=d.005 250.648 12 14586 -.064 Krobusek 256.748 10 14605 -.058 Krobusek 309.660 9 14770 -.066 Krobusek TZ Lyrae, sigma=d.005 239.693 10 40789 +.019 Krobusek 247.630 6 40804 +.024 Krobusek 248.680 10 40806 +.016 Krobusek 265.614 11 40838 +.028 Krobusek 266.665 11 40840 +.021 Krobusek X Trianguli, sigma=d.003 337.560 8 4905 -.034 Krobusek W Ursae Minoris, sigma=d.010 235.706 9 5160 -.028 Krobusek 235.715 9 5160 -.019 Mallama 264.645 10 5177 -.009 Krobusek RU Ursae Minoris, sigma=d.007 236.744 18 30062 -.011 Krobusek 245.665 13 30079 -.014 Krobusek 265.619 13 30117 -.007 Krobusek BRUCE A. KROBUSEK ANTHONY D. MALLAMA Chagrin Falls, Ohio USA Ritter Astrophysical Research Center The University of Toledo Toledo, Ohio 43606 USA