THE ASTRONOMER Electronic Circular No 715 1993 Mar 06 16.33UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England. Telephone/FAX(0256)471074 Int:+44256471074 TELEX: 9312111261 Answerback: TA G TELECOM GOLD: 10074:MIK2885 GMH at UK.AC.RUTHERFORD.STARLINK.ASTROPHYSICS STARLINK: RLSAC::GMH GMH at UK.AC.CAM.ASTRONOMY.STARLINK STARLINK: CAVAD::GMH ------------------------------------------------------------------- SUPERNOVA 1993F IN ANONYMOUS GALAXY C. Pollas reports his discovery of an apparent supernova of mag about 18.5 on two technical pan films (limiting mag 21-22) taken Jan. 18.97 and 20.94 UT by D. Albanese and himself with the 0.9-m Schmidt telescope at the Observatoire de la Cote d'Azur. The candidate, at R.A. = 7h54m26s.45, Decl. = +20 13'04".8 (equinox 1950.0), is superimposed on the nuclear region of a galaxy of mag 18, being roughly 0".6 east and 1".5 south of the galaxy's center. No such stellar image is present on a technical pan plate (similar limiting magnitude) obtained in 1990 January, though there is perhaps a condensation of mag about 20 nearly at the position of the supernova visible on an old film. A nearby star (mpg = 19) has end figures 20s.92, 14'17".7. IAUC 5717 ALPHA ORIONIS (cf E710,E711) A. K. Dupree, E. Guinan, and M. Smith further report, in addition to the information on IAUC 5716: "Photometry at Villanova on Feb. 28 UT suggests that alpha Ori has paused in its decline in brightness at V about +0.9. International Ultraviolet Explorer observations were acquired as a part of the ongoing monitoring program on Feb. 24. Radial velocity measurements in the H-alpha region continue at the McMath Solar Telescope at Kitt Peak." IAUC 5717 CY URSAE MAJORIS Taichi Kato, Japan e-mails that he has detected superhumps in CY UMa during its current outburst (cf E712) and confirms that it is a new SU UMa-type variable. Further details follow: Reduction of V-band CCD observations on Mar. 5 yields following results. 1) Mean magnitude The star declined from +0.3 to +0.4 in nine hours (comarison: GSC 105705.38 +493730.4 (2000.0) V=12.9). The star may have started its final decline from the present superoutburst. 2) Detection of superhumps The hump structures have mean amplitudes of 0.11 mag in V. The rises are steeper than the declines as in usual superhumps. The eclipses are not detected. 3) The superhump period The maxima of superhump occurred at 5.476, 5.546, 5.620, 5.690, 5.763, and 5.838 UT. The times are well expressed by the following formula: Max UT = Mar. 5.475 + 0.0723 E The baseline of the observation was long enough, therefore the period will be accurate to at least 0.5%. The period is not in agreement with the previously published one (Var.Star Bull.) which was based on visual observations only.