THE ASTRONOMER Electronic Circular No 443 1990 Sept 11 18.15UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074 Telex: 94082518 Answerback: TAGUY Microlink: MAG60138 JANET:GMH @ UK.AC.CAM.ASTRONOMY.STARLINK GUYH@UK.AC.SUSSEX.CLUSTER -------------------------------------------------------------------- SUPERNOVA 1990aa IN ANONYMOUS GALAXY S. Perlmutter, C. Pennypacker, S. Carlson, H. Marvin, R. Muller and C. Smith report that the Berkeley Automated Supernova Search has discovered a supernova 12" east and 8" south of the nucleus of an anonymous galaxy at R.A. = 0h50m.2, Decl. = +28D45' (1950.0). The object, of mag 17 +/-0.5, was found on three images obtained on Sept. 4.385, 4.387 and 4.431 UT. The supernova was not present to limiting mag 18 (90-percent-confidence) on an image obtained on Aug. 19. It is present (but below the detection threshold) on images from Aug. 25, 28 and Sept. 3. IAUC 5087 M. Richmond, University of California at Berkeley, informs us that the "anonymous" host galaxy for this supernova is probably UGC 00540 = MCG +05-03-016. IAUC 5088 RX ANDROMEDAE Patrick Schmeer provides recent estimates of this variable: Aug 14.994: 11.7 , 18.025: 11.6 , 19.947: 11.6 , 22.110: 11.1 , 23.013: 11.1 , 24.013: 11.2 , 25.035: 11.1 , 27.967: 11.2 , 29.040: 11.2 , 29.87 : 11.2 , Sept. 1.984: 11.4 , 4.011: 11.2 , 6.106: 11.4 8.958, 11.4; 9.990, 11.4 This Z Cam-type dwarf nova is apparently undergoing its second standstill since 1986 December (cf. E382) as its brightness varied from Aug. 14 to Sept. 9 only between mag 11.1 and 11.7. The previous standstill of RX And occurred from 1989 Dec. 25 to 1990 May. Guy M Hurst