2010CBET.2541....1B

The Central Bureau has received reports of the independent discoveries of an apparent supernova in NGC 2929 on unfiltered CCD images – the first by T. Boles (Coddenham, England, 0.35-m reflector), and the second by J. Newton and T. Puckett (0.40-m reflector at Portal, AZ, U.S.A.). Boles reports the position of 2010jn as R.A. = 9:37:30.24, Decl. = +23:09:33.3, which is approximately 5".9 east and 8".7 south of the center of NGC 2929; Puckett provides position end figures 30s.20, 33".6 (offset 4".6 east and 8".5 south of the center of NGC 2929). Available magnitudes, from unfiltered CCD images unless noted otherwise: 1995 Nov. 30, [21.0 (Digitized Sky Survey, blue plate; via Boles); 1998 Apr. 22, [20.5 (DSS, red plate; via Boles); 2009 Jan. 6, [19.5 (Boles); 2009 Oct. 4, [19.9 (Puckett); 2010 Oct. 21.160, 17.0 (Boles; discovery); Nov. 5.47, 17.2 (Newton and Puckett; discovery); 6.48, 16.9 (Puckett). Boles subsequently noted that 2010jn was reported by Howell et al. (see website URL http://www.astronomerstelegram.org/?read=2934), where they reported position end figures 30s.30, 33".6 and the following R-band magnitudes: Oct. 8.5, [20.3; 11.5, 19.6 (marginal); 12.5, 19.2 (discovery); 13.5, 18.7. Howell et al. add that a spectrogram obtained on Oct. 13 with the "Gemini North" telescope showed 2010jn to be a type-Ia supernova around 15 days before maximum light, noting that the blueshift of the Si II 635.5-nm feature indicates velocities in excess of 20000 km/s ("among the highest ever seen for non-detached features" in a type-Ia event).