THE ASTRONOMER Electronic Circular No 563 1991 Sept 18 20.30UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074 Telex: 9312111261 Answerback: TA G JANET BOXES: GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER TELECOM GOLD: 10074:MIK2885 PRESTEL 256471074 ------------------------------------------------------------------- SUPERNOVA 1991av IN ANONYMOUS GALAXY J. Mueller reports her discovery of a supernova at R.A. =21 53 28.5, Decl. = +0 45 38 (1950.0), 7".4 E and 4".7 north of the nucleus of an anonymous galaxy. The supernova was of mag about 18 (red) on a plate taken on Sept. 4 by C. Brewer and herself with the 1.2-m Oschin telescope in the course of PSS II. A spectrum obtained by M. Schmidt and D. Schneider with the 5-m Hale telescope (+ 4 shooter + spectrograph) on Sept. 6 shows it to be of type II. IAUC 5338 COMET McNAUGHT-RUSSELL (1991w) The following precise positions have been reported: (cf E560) 1991 UT R.A. (1950) Decl. m1 Observer Sept. 5.55454 21 54 24.79 - 2 09 36.9 McNaught 6.55718 21 53 53.12 - 2 17 57.9 " 7.63473 21 53 19.22 - 2 26 55.1 18 Seki 7.64827 21 53 18.77 - 2 27 00.9 " 8.60880 21 52 48.86 - 2 35 01.9 McNaught R. H. McNaught (Siding Spring). Uppsala Southern Schmidt. Film dark on Sept. 6. T. Seki (Geisei). 0.6-m reflector. The following parabolic orbital elements, from the nine available observations Sept. 3-8, are rather uncertain, but they suggest that this comet may have a near-record large perihelion distance: T = 1991 Jan. 12.975 ET Peri. = 154.056 Node = 149.352 1950.0 q = 7.11258 AU Incl. = 104.876 1991 ET R.A. (1950) Decl. Delta r m1 Sept. 1 21 56.85 - 1 31.7 6.277 7.266 17.6 11 21 51.59 - 2 54.9 21 21 46.79 - 4 16.8 6.412 7.294 17.7 Oct. 1 21 42.64 - 5 35.5 11 21 39.28 - 6 49.2 6.667 7.323 17.8 21 21 36.84 - 7 56.8 31 21 35.34 - 8 57.6 7.009 7.355 17.9 Nov. 10 21 34.79 - 9 51.2 20 21 35.16 -10 37.6 7.390 7.388 18.0 IAUC 5339 SUPERNOVA 1991aw IN Zw 322-02 C. Pollas, Observatoire de la Cote d'Azur, reports his discovery of a possible supernova at R.A. = 17h42m20s.49, Decl.= +67d30'29.3" (equinox 1950.0), 1".9 west and 9".3 north of the center of the galaxy Zw 322-02 = KA 155, a spiral galaxy of mpg = 15.4. The supernova, of mag about 20, appeared on 4415-emulsion films (limiting mag 21) obtained with the 0.9-m Schmidt at Caussols on Sept. 4.9 and 5.9 UT. Nothing is visible on similar films obtained on July 9.0 and June 9.0 UT (to limiting mag 22), and neither is anything on the POSS prints. The object is near SAO 017612. IAUC 5340 Guy M Hurst