------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2670 2010 Aug 25 11.19UT 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 Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- SUPERNOVA 2010hb IN UGC 2537 On 2010 August 24 we received an e-mail from Tom Boles reporting an apparent supernova in UGC 2537 during the course of searches for the UK Nova/Supernova Patrol. The object, of magnitude 17.5 was recorded on multiples images with the 0.35-m Schmidt-Cassegrain telescope obtained on 2010 Aug 24.007UT and is located at: RA 03h 07 01.66s DEC +46 37' 20.3" (2000), 31.3"W and 4.3"N of the centre of the host galaxy. Nothing is present at this position on Tom's images of 2010 Mar 2 and Aug 5 (limiting mag 19.5) nor on Digitised Sky Survey Plates from 1989 Oct 5 (limiting red mag 20.5), and 1989 Sept 8 (limiting blue mag 21.0). In a further e-mail Tom reports confirmatory images of Aug 24.502UT obtained with the Sierra Stars 0.61-m Cassegrain telescope in California. End figures for night two are RA 1.66s and DEC 20.3". Mag = 17.6 V. The object was announced on CBET 2424 as Supernova 2010hb. Congratulations to Tom on the discovery of his 134th supernova. SUPERNOVA 2010gw IN IC 4992 Discovery by Stuart Parker. New Zealand of a possible supernova (CBET 2410): SN 2010 UT R.A. (2000.0) Decl. Mag. Offset 2010gw Aug 10.61 20 23 25.31 -71 34 04.9 16.6R 12 "W, 11 "S SUPERNOVA 2010gx (=CSS 100313:112547-084941) Discovery by PS1 collaboration of a possible supernova (CBET 2413): SN 2010 UT R.A. (2000.0) Decl. Mag. Offset 2010gw Mar 13 11 25 46.71 -08 49 41.4 18.6r A. Pastorello et. al. Queens University, Belfast report that a luminous optical transient detected by three wide-field surveys has evolved into a type-Ic supernova. The Catalina Real Time Transient Survey first announced the discovery of an optical transient (designated as CSS 100313:112547-084941) on Mar. 13 and subsequently the "Palomar Transient Factory" (PTF) collaboration reported an independent discovery on images obtained during Mar. 5-16. It was also noted that the transient was also detected by PS1 in the course of the 3Pi survey during Mar. 12-23 (which they designated PS1-1000037). Further detailed spectroscopic monitoring with the Gemini South telescope and the William Herschel Telescope by the PS1 team shows that -- 25 days after discovery -- the transient evolved unambiguously into a type-Ic event. The spectra at +25 days are most similar to those of SN 1994I (at six days before peak; Baron et al. 1996, MNRAS 279, 799) and SN 2003jd (at peak; Valenti et al. 2008, MNRAS 383, 1485). This indicates a link between the "ultra-bright" optical transients and type-Ic supernovae; further details are reported by Pastorello et al. (2010, Ap.J., submitted). SUPERNOVA 2010gy IN ANONYMOUS GALAXY Discovery by Pan-STARRS 1 Medium Deep Survey of a possible supernova (CBET 2414): SN 2010 UT R.A. (2000.0) Decl. Mag. Offset 2010gy Aug 5.59 02 27 12.04 -04 32 04.87 20.8g The transient has subsequently risen in brightness to magnitude g = 18.4 on Aug. 14.6. A spectrum of Aug 14.4 revealed the transient to be a normal type-Ia supernova near maximum light. Guy M Hurst