Electronic Telegram No. 2405
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Room 209; Dept. of Earth and Planetary
 Sciences; Harvard University; 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbat@iau.org; cbatiau@eps.harvard.edu
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVAE 2010gl AND 2010gr
     I. K. W. Kleiser, J. M. Silverman, D. Poznanski, and A. V. Filippenko,
University of California, Berkeley, report that inspection of CCD spectra
(range 340-1000 nm), obtained on Aug. 10 UT with the 3-m Shane reflector (+
Kast) at Lick Observatory, shows that 2010gl (CBET 2382) is a type-Ia
supernova; after removal of the host-galaxy recession velocity of 5500 km/s,
determined from narrow absorption features, the absorption minimum of the
Si II 635.5-nm line is found to be blueshifted by about 10400 km/s.
Cross-correlation with a library of supernova spectra using the "SuperNova
IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates
that 2010gl is about one week past maximum brightness.  SN 2010gr (CBET 2396)
is a type-Ib/c (probably Ic) supernova, 1-3 months past maximum brightness.
     S. Nakano (Sumoto, Japan) forwards a report from a Japanese amateur
named Nobuhisa Kojima who independently discovered 2010gl on July 21.67 UT at
mag 16.0; evidently unaware of the discovery report on CBET 2382, Koichi
Itagaki (Teppo-cho, Yamagata) confirmed 2010gl at mag 16.0 on July 23.57.
Subsequently, Kojima contacted Nakano to report that his unfiltered CCD
image taken on Aug. 6.65 shows 2010gl still bright at mag 15.8, using a
0.25-cm f/6.3 Schmidt-Cassegrain (+ Bitran BJ-41L camera).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 August 11                   (CBET 2405)              Daniel W. E. Green