------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1989 2004 Apr 13 18.00UT 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.theastronomer.org ------------------------------------------------------------------- SUPERNOVA 2004bh IN UGC 5161 On 2004 April 10 an e-mail was received from Mark Armstrong of Rolvenden, England reporting his detection in UGC 5161 of a possible supernova during the course of searches for the UK Nova/Supernova Patrol. He obtained the following astrometry from unfiltered CCD images with a 0.35-m Schmidt-Cassegrain telescope: 2004 04.09.96340 RA 09h 40m 56.47s DEC +27 46'46.6" (2000) Mag 16.9 Offsets 1.3" west and 6" north. Mark also reports he has an earlier image from Apr 6.906 where the suspect appears to be present but the image is blurred due to wind. There is no trace of the suspect on his previous images from 2003 Feb 6, Nov 12 (limiting magnitude 18.0) and 2004 Feb 26 (limiting magnitude 18.5). There is also nothing on POSS-II plates. In response to an appeal from Mark, Martin Mobberley obtained a confirmatory image on 2004 April 10.873UT using a C14+ME+ST9XE. The end figures from astrometry: RA 56.40s DEC 47.5". Mark also obtained a further image of the suspect on April 11.063UT. The supernova was designated 2004bh and announced on IAUC 8320. Congratulations to Mark on his 60th discovery. COMET C/2004 F4 (BRADFIELD) Martin Mobberley reports: Assuming the initial orbital elements are reasonably accurate, this is an intrinsically faint comet (Abs Mag = 9) which only appears so bright because of its very small q of 0.169 AU. Its faintness and southern origin would explain how it has sneaked past LINEAR and NEAT. After perihelion on April 17th, C/2004 F4 Bradfield moves rapidly north and will crawl 10 degrees above UK observers' northeast horizons in the pre-dawn nautical twilight by April 27th (03:10 UT). Interestingly, the day before, April 26th, Bradfield should be (if the elements are OK) within a degree of 9th mag C/2003 T3 Tabur, making for an interesting photo opportunity: two comets, 4th & 9th mag, within 1 degree in Pisces, if at a VERY low altitude! By May 4th, C/2004 F4 Bradfield will be at 10 degrees altitude in the rapidly disappearing UK pre-dawn astronomical twilight (01:44 UT), i.e. in a dark sky. However, the sky will not be dark, because the troublesome Moon, Full on May 4th, will be a real nuisance for the whole of this comet's best weeks. The Moon only exits the morning sky from Mid May (New on May 19th). By this time C/2001 Q4 should be stealing the show! Although Bradfield may still be mag 5 on April 27th, it will be have faded to mag 7 by May 4th, i.e. in the space of one week. From the second week in May, Bradfield will be circumpolar from UK latitudes, but, despite this, barely rises above the north horizon before midnight. It will always be best in the morning sky but, as May proceeds, seeing it in a dark sky will increasingly become a battle from the UK, as the Sun is never far below the north horizon once the Moon has gone. By May 10th, Bradfield will have reached 22 degrees altitude above the UK northeast horizon at nautical twilight (02:37 UT). However, at astronomical twilight (01:18 UT at 52N) on that day, it will only be 13 degrees up and about 8th mag. By then it will be passing through Andromeda, a few degrees east of M31. Bradfield will continue to rise, almost vertically, above the northeast UK pre-dawn horizon throughout May, attaining 30 degrees altitude at nautical twilight on May 28th (01:56 UT). However, by the end of May it will have faded to a dismal 11th magnitude as it crosses the Andromeda/Cassiopiea border. Bradfield should peak in declination at +68 in August, but will be a 4th mag CCD object by then. Guy M Hurst