THE ASTRONOMER Electronic Circular No 508 1991 Apr 15 19.15UT 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 1991O IN ANONYMOUS GALAXY J. Mueller reports her discovery of a supernova of red magnitude about 18, located at R.A. = 14h23m33s.9, Decl. = +65 59'06".8 (1950); the galaxy's centre is located at R.A. =14h23m32s.3, Decl. = +65 59'01".6. The discovery plate was taken by Mueller on Mar. 18 UT with the 1.2-m Oschin Telescope in the course of the second Palomar Sky Survey. IAUC 5233 NOVA HERCULIS 1991 J. A. Mattei, AAVSO, forwards photoelectric observations by L.F. Snyder, Crystal City, NV, noting the presence of modulation with amplitude of 0.096 mag on Mar. 30 and 0.061 mag on Mar. 31 (the durations of the observations were not long enough to determine periodicity): Mar. 30.466 UT, V = 9.54; 30.473, 9.47; 30.489, 9.55; 30.496, 9.51; 31.488, 9.69; 31.491, 9.65; 31.524, 9.71. IAUC 5233 A. Izumo, Yokohama Science Center, forwards the following photoelectric observations by O. Oshima, Kurashiki, Japan: Apr. 1.771 UT, V = 9.74 +/- 0.02, B-V = +0.38 +/- 0.03, U-B = -0.91 +/- 0.04; Apr. 2.780, V = 10.06 +/- 0.02, B-V = +0.33 +/- 0.03, U-B = -0.94 +/- 0.05. IAUC 5234 Further visual estimates: Apr 5.79, 11.5 (R.McNaught); 6.06, 10.9 (P.Schmeer); 6.07UT, 10.9 (W.Worraker); 8.08UT, 11.5 (G.Poyner); 8.81UT, 12.2 (McNaught); 9.14UT, 11.9 (A.Pereira); 10.113UT,11.7 (Schmeer); 11.090UT,12.0 (Schmeer); 12.096UT,12.0 (Schmeer); 13.02UT, 11.9pv (M.Mobberley) 13.13UT, 12.0 (Worraker); 13.16UT, 12.0 (Worraker) SS LEONIS MINORIS T. E. Harrison, Mt. Stromlo Observatory, reports: "B, V, R, and I CCD images, obtained with the Siding Spring 1.02-m telescope on Apr. 4.5 and 5.5 UT, of the field of SS LMi show an object at the position marked by Duerbeck (1987, Space Sci. Rev. 45, 177) for this supposed 1980 nova. The object is fairly red, at Cousins-Kron magnitude I about 17.7 (the object to the immediate north has I = 16.4). Advantage should be taken of this apparent brightening to determine the nature of this object." IAUC 5233 BZ UMA Stefan Korth, Germany, relays that J.Pietz, Germany has observed an outburst of this star: Apr 10.854UT, 15.8 (Korth); 11.863, [12.6 (Pietz); 12.847, 12.1 (Pietz); 12.906, 12.2 (Pietz). SUPERNOVA 1991N IN NGC 3310 Stefan Korth provides estimates of this object (cfE504): Apr 2.924UT, 13.9; 3.853, 14.1; 6.049, 14.5; 10.853, 14.5; 13.044, 14.6 Guy M Hurst