THE ASTRONOMER Electronic Circular No 632 1992 Apr 26 13.26UT 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 JANET BOXES: GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER TELECOM GOLD: 10074:MIK2885 PRESTEL 256471074 ------------------------------------------------------------------- COMET SHOEMAKER-LEVY (1991a1) Observers are reminded that this comet is expected to brighten to around magnitude 6.5 and be well placed at high northerly declination over the coming months. Revised elements and ephemeris (calculated using EPH.EXE by N.James) follow: T 1992 July 24.5533 TT w 145.22740 ) e 0.99985900 O 49.05510 ) 2000.0 q 0.8367200 A.U. i 113.50890 ) Source: MPC 19655 Positions are geocentric m = 7.5 + 5.0 log R + 10.0 log r Date R.A. (2000) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1992 Apr 28.00 0 52.65 +39 13.5 2.493 1.722 31.9 11.8 48 29 1992 May 3.00 0 56.85 +40 42.8 2.396 1.656 33.8 11.6 53 28 8.00 1 1.32 +42 22.2 2.293 1.589 35.9 11.3 58 26 13.00 1 6.13 +44 13.4 2.184 1.523 38.2 11.0 65 25 18.00 1 11.39 +46 18.5 2.069 1.457 40.5 10.7 72 23 23.00 1 17.29 +48 40.2 1.950 1.392 42.9 10.4 82 23 28.00 1 24.16 +51 21.8 1.826 1.327 45.3 10.0 93 22 1992 June 2.00 1 32.52 +54 27.7 1.700 1.263 47.7 9.7 108 22 7.00 1 43.33 +58 3.1 1.571 1.201 49.9 9.3 126 23 12.00 1 58.54 +62 13.7 1.442 1.141 51.9 8.9 149 26 17.00 2 22.54 +67 3.8 1.316 1.084 53.5 8.4 179 30 22.00 3 6.92 +72 27.5 1.196 1.030 54.7 8.0 217 40 27.00 4 45.36 +77 25.8 1.088 0.980 55.4 7.6 262 64 1992 July 2.00 7 50.13 +77 55.1 0.996 0.936 55.4 7.2 314 110 7.00 10 5.86 +70 51.6 0.930 0.899 54.8 6.9 360 143 12.00 11 4.62 +59 50.9 0.897 0.869 53.6 6.7 387 158 SUPERNOVA 1992U IN ESO 74-G4 J. Maza, University of Chile; and M. Hamuy, Cerro Tololo Interamerican Observatory, report the discovery by R. Antezana of a supernova located about 18" east and 9" north of the nucleus of the spiral galaxy ESO 74-G4 (= PGC 65177, R.A. = 20h35m42s, Decl. = -70d52'21", equinox 1950.0). The supernova, of mpg about 18.5, was found on a 20-min unfiltered IIa-O plate taken by Antezana with the CTIO Curtis Schmidt telescope on Apr. 9.359 UT. It was not present (mpg [20) on a IIa-O plate taken with the same telescope by L. Wells on Apr. 3. Confirmation was made by Y.-C. Kim from B and V CCD images obtained in nonphotometric conditions on Apr. 15.4 with the CTIO 0.9-m telescope. IAUC 5499 SUPERNOVA 1992H IN NGC 5377 Visual magnitude estimates: Feb. 22.98 UT, 14.6 (M. Villi and G. Cortini, Mount Colombo, Italy); 23.94, 14.2 (S. Pesci, Milan, Italy); 28.29, 15.2 (W. Wren, McDonald Observatory); 29.98, 14.5 (Pesci); Mar. 30.25, 15.5 (Wren); Apr. 9.26, 15.5: (Wren); 19.24, 15.7 (Wren). IAUC 5502 Guy M Hurst