------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1274 1998 Feb 28 20.50UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK GMH at AST.STAR.RL.AC.UK WORLD WIDE WEB http://www.demon.co.uk/astronomer ------------------------------------------------------------------- SUPERNOVAE: 1998F-1998N P. Garnavich, Harvard-Smithsonian Center for Astrophysics (CfA), reports that the High-Z Supernova Search Team has discovered nine supernovae on CCD images taken with the Cerro Tololo Interamerican Observatory (CTIO) 4-m telescope by R.Schommer (CTIO), B. Schmidt (Mount Stromlo and Siding Springs Observatory), and S. Jha and P. Challis (CfA). The supernovae were identified by subtracting images taken on 1997 Dec. 29-30 UT from those obtained on 1998 Jan. 23-24. The candidates were confirmed with spectra and images taken on Jan. 25-26 and Feb. 1 with the Keck-2 telescope by A. V. Filippenko, A. G. Riess, and D. C. Leonard (University of California, Berkeley). SN 1998 UT R.A. (2000) Decl. I z type 1998F Jan. 23 04 16 50.13 -05 44 59.6 24.5 0.52 ? 1998G Jan. 23 08 03 37.02 +06 10 13.9 22.8 0.30 II? 1998H Jan. 23 08 04 51.47 +05 36 39.3 23 0.66 ? 1998I Jan. 23 08 04 51.56 +05 15 47.7 23.6 0.89 Ia 1998J Jan. 23 09 31 10.48 -04 45 36.5 23.5 0.83 Ia 1998K Jan. 24 04 13 42.86 -05 50 45.2 23.8 ? ? 1998L Jan. 24 11 33 36.63 +04 35 04.6 23.6 ? II? 1998M Jan. 24 11 33 44.37 +04 05 13.4 23.3 0.63 Ia 1998N Jan. 24 11 33 29.39 +03 51 12.5 23.1 0.26 ? IAUC 6819 (extract) SUPERNOVAE 1998O, 1998P, 1998Q L. Germany reports that the Mount Stromlo Abell Cluster Supernova Search Team has discovered three apparent supernovae on V and R CCD images (limiting mag V = 21.5) taken by R. Hola at the Mount Stromlo 1.27-m telescope (+ Macho Camera): SN Date UT R.A. (2000.0) Decl. V Offset 1998O Jan. 27 13 39 34.98 -35 46 32.5 20.9 1".1 E, 16".4N 1998P Jan. 27 13 37 17.63 -35 27 32.6 20.1 2".3 E, 2".5 N 1998Q Jan. 27 13 32 46.38 -31 37 23.5 18.5 0".1 E, 1".5 N IAUC 6820 (extract) COMET P/1998 B1 (SHOEMAKER-LEVY 8) C. W. Hergenrother has recovered comet P/1992 G2 (= 1992f = 1992 XV) on images obtained with the Smithsonian Astrophysical Observatory's 1.2-m reflector at Mt. Hopkins on Jan. 22. He confirmed the recovery on images obtained with the Lunar and Planetary Laboratory's 1.5-m reflector at the Catalina Station on Jan. 28, when there was a moderately diffuse 5" coma but no tail on a 900-s exposure. 1998 UT R.A. (2000) Decl. m1 Jan. 22.23128 7 28 13.12 +14 00 30.7 21.8 28.34848 7 24 02.92 +14 11 32.2 28.37097 7 24 02.00 +14 11 35.3 22.6 Hergenrother's measurements above show that the prediction by Brian Marsden on MPC 27082 requires correction by Delta T = +0.03d. The following improved orbital elements represent 76 observations 1992-1998 with mean residual 0".8: Epoch = 1999 Dec. 8.0 TT T = 1999 Dec. 10.5994 TT Peri. = 22.5940 e = 0.289451 Node = 213.3174 2000.0 q = 2.721257 AU Incl. = 6.0505 a = 3.829792 AU n = 0.1315047 P = 7.495 years IAUC 6821 (extract) Guy M Hurst