THE ASTRONOMER Electronic Circular No 290 1989 Apr 25 20.13UT. Telecom Gold 72:MAG60138 JANET:GMH at UK.AC.RO.GREENWICH-STARLINK Ed:Guy M Hurst, 16, Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP, England. Telephone:(0256)471074.Int:+44256471074 Telex:265871(MONREF G) Quote"72:MAG60138 ATT G.HURST"in FIRST line. ------------------------------------------------------------------- TA AGM 1989 This year's AGM will be held on (Saturday) 1989 June 24 in Basingstoke (venue details to be finalised shortly). We are delighted to announce that Dr. Brian Marsden, of the Central Bureau for Astronomical Telegrams will be visiting us from USA and will be our main speaker on this occasion. Please book this date in your diary and I will send further details very shortly. SUPERNOVA 1989H and 1989I C. Pollas, Observatoire de la Cote d'Azur, reports the discoveries of two apparent supernovae found on plates exposed with the CERGA Schmidt telescope. SN 1989H, found on a plate taken Feb. 7.16 UT, was at B = 20 and located in an H II region of the south arm of MCG +6-30-64 (R.A. = 13h36m.4, Decl. = +32 32', equinox 1950.0); the SN is 3".5 east and 16".3 south of the galaxy's center. Further magnitude estimates: Feb. 8.20, R =19.5; 9.15, R = 19.5; Mar. 11.09, B about [21. A faint, less-stellar object (probably an H II region) is visible at mag about 21 on POSS B plate in the location of SN 1989H. SN 1989I, in an anonymous galaxy, was found on plates taken Mar. 11.15 and 9.19 (B = 19) by A. Maury and Pollas and was confirmed with the 2-m Pic du Midi Observatory telescope on Apr. 2 by E. Davoust, A. Klotz, and J. L. Nieto. SN 1989I is located at R.A. = 14h34m15s.72, Decl. = +14 53'09".1 (equinox 1950.0), and lies 3".4 west and 4".5 south of the galaxy's center. IAUC 4774 SU URSAE MAJORIS A. Udalski, York University, Toronto, and Warsaw University Observatory, writes: "Following notification by J. A. Mattei, AAVSO, of the superoutburst of this dwarf nova (cf. IAUC 4773), I obtained three 6-hr photometric observing runs of SU UMa using the 0.61-m/0.48-m twin photometric system of the David Dunlop Obsy during Apr. 21-23. Superhumps with an amplitude of about 0.2 mag were discovered. Based on timing of nine superhump maxima, the preliminary superhump period is about 113.5 min. The superhump period is therefore about 3 percent longer than the orbital one (Thorstensen et al. 1986, Ap.J. 309, 721), similar to that of other SU UMa-type stars. Discovery of superhumps in SU UMa proves that the star is indeed a typical SU UMa-type dwarf nova and a good prototype star for the whole class." Further visual magnitude estimates by P. Schmeer, Bischmisheim, W. Germany: Apr. 23.89 UT, 11.7; 25.02, 11.7. IAUC 4774 Guy M Hurst