------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1220 1997 Aug 05 00.00UT 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 ------------------------------------------------------------------- COMET C/1997 O1 (Tilbrook) Improved orbital elements by Brian Marsden T 1997 July 13.2599 TT w 336.0222 ) e 1.00000000 O 231.1502 ) 2000.0 q 1.373622 i 115.8011 ) Source: MPEC P03 (from 34 observations 1997 July 23-Aug. 3) m = 8.0 + 5.0 log R + 10.0 log r SUPERNOVA 1997da IN IC 1216 M. Schwartz reports his discovery of an apparent supernova (mag about 17) on a CCD image taken with the 0.35-m Tenagra Observatory patrol telescope on July 31.399 UT. SN 1997da is located 3" west and 6" south of the nucleus of IC 1216. G. V. Williams, Smithsonian Astrophysical Observatory, provides the following measurement for SN 1997da from a GIF image supplied by Schwartz: R.A. = 16h15m54s.96, Decl. = +68o20'53".3 (equinox 2000.0; uncertainty about 1"). A. V. Filippenko, D. C. Leonard, and A. M. Gilbert, University of California at Berkeley, report that CCD spectra (range 330-1000 nm) obtained with the Lick 3-m Shane reflector on Aug. 4 show this to be a supernova of type II, probably within 1.5 months after outburst; H-alpha has a P-Cyg profile, and there are some Fe II lines. IAUC 6711 SUPERNOVA 1997db IN UGC 11861 Schwartz also reports his discovery of an apparent supernova on a CCD image taken on Aug. 2.30 UT. The following position and magnitude were measured by W. Offutt (Cloudcroft, NM) from an image supplied by Schwartz: R.A. = 21h56m20s.53, Decl. = +73o14'49".4 (equinox 2000.0), V = 16.9. Note that SN 1995ag was in the same galaxy (IAUC 6244). Filippenko et al. report that CCD spectra (range 330-1000 nm) obtained with the 3-m Shane reflector on Aug. 4 show that SN 1997db is a supernova of type II, many months past outburst and entering the nebular phase. There are prominent emission lines of [Ca II] 730-nm and the Ca II near-infrared triplet, as well as very strong H-alpha. SN 1997db is located about 14" west and 50" south from the ill-defined host-galaxy nucleus. IAUC 6711 TA AGM Further to the announcement on EC 1219, Dr Robert Smith (University of Sussex) has kindly agreed to speak at the AGM on a variable-star related theme (title TBA). Martin Mobberley