------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1143 1996 Nov 20 20.51UT 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 ------------------------------------------------------------------- SUPERNOVA 1996bt IN ANONYMOUS GALAXY P. Garnavich, Harvard-Smithsonian Center for Astrophysics, reports that P. Berlind, Fred L. Whipple Observatory (FLWO), has discovered a supernova in an elliptical galaxy located at R.A. = 6h51m58s.0, Decl. = +16 17'43" (equinox 2000.0). The supernova was recognized by its spectrum, obtained on Nov. 10.49 UT with the Tillinghast 1.5-m telescope in the course of the 'Winter Plane' redshift survey (principal investigator C. Pantoja). The spectrum shows SN 1996bt to be a type-Ia supernova about 10 days after maximum. CCD images obtained by E. Barton with the FLWO 1.2-m telescope on Nov. 10.50 show the supernova to be 1".5 west and 1".2 north of the galaxy's centre. Accurate photometry is difficult, due to the blending of the supernova and galaxy images, but point- spread-function fitting gives a magnitude of B = 16.5 +/- 0.1. IAUC 6503 SUPERNOVA 1996bu IN NGC 3631 S. Nakano, Sumoto, Japan, communicates that Reiki Kushida, Yatsugatake South Base Observatory, reports her discovery on an unfiltered CCD image taken on Nov. 14.793 UT with a 0.40-m f/5 reflector of an apparent supernova (mag 17.3) located at R.A. = 11h20m59s.18, Decl. = +53 12'08".0 (equinox 2000.0; measurement by Y. Koshida), which is 32" west and 117" north of the centre of NGC 3631. No star at this position is visible on her frames taken on 1996 Feb. 13 and May 9. P. Garnavich, P. Challis, and R. Kirshner, Harvard-Smithsonian Center for Astrophysics, report that C. Hergenrother and W. Brown obtained CCD images of SN 1996bu with the Whipple Observatory's 1.2-m reflector on Nov. 17.49 UT, yielding V = 17.6 and B = 18.1 and position end figures 59s.30, 08".4 for the supernova. Spectra obtained with the Multiple Mirror Telescope by R. Marzke and S. Odewahn on Nov. 18.5 show SN 1996bu to be a peculiar type-II supernova. IAUC 6505 Following this announcement Mark Armstrong notes that he had recorded a faint pre-discovery image of this supernova on a UK Nova/Supernova Patrol image of 1996 Nov 14.212UT. The object, recorded on an unfiltered CCD image obtained with the 0.26-m Schmidt-Casegrain telescope, was of approximately magnitude 18. This has now been communicated to the Central Bureau. The Editor notes that Supernovae 1964A and 1965L also occurred in this galaxy suggesting that the high frequency of detected supernovae makes this galaxy a prime target for the UK Patrol. E-MAIL Due to recent changes in the central computers used by Demon, our Internet Provider, we have experienced regular computer crashes on the TA machine over recent weeks which culiminated in an inability to send any replies last weekend. This appears to only affect those using older versions of the DOS software. Overnight, with considerable assistance from David Hurst, we converted over 200 pending messages to new windows software which we are now testing but apologise for the slowness of replies to recent enquiries. We hope to clear this backlog soon. Guy M Hurst Turnpike evaluation. For Turnpike information, mailto:info@turnpike.com