Electronic Telegram No. 2557
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2010ke
     W. Zheng, University of Michigan; J. Vinko, University of Szeged; R.
Quimby, California Institute of Technology; A. Romadan, N. Whallon, S. B.
Pandey, F. Yuan, and C. Akerlof, University of Michigan; P. Pasque and M.
Verkinderen, Cousino High School; and J. C. Wheeler And E. Chatzopoulos,
University of Texas, on behalf of the ROTSE collaboration, report the
discovery of a new supernova (mag about 18.1) in unfiltered images taken on
Nov. 14.34 UT with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory.
The new object -- which was observed again on Nov. 23.11 at mag about 18.0
and on Nov. 24.06 at mag about 18.2 -- is located at R.A. = 0h57m24s.62,
Decl. = -0o57'51".4 (equinox 2000.0; uncertainty about 1"), which is 0".2
east and 1".9 south of the center of the presumed host galaxy (SDSS
J005724.60-005749.5).  A finding chart for the object can be found at
website URL http://www.rotse.net/rsvp/j005724.6-005751/j005724.6-005751.jpg.
A spectrum, obtained on Nov. 25.10 UT with the 9.2-m Hobby-Eberly Telescope
(+ Marcario Low-Resolution Spectrograph) by S. Odewahn, shows 2010ke to be a
type-Ia supernova at more than a week after maximum light.  The spectrum
contains a strong Si II feature and several other broad lines of S II and Fe
II, characteristics of type-Ia supernovae.  The best-matching template
spectrum in SNID (Blondin and Tonry 2007, ApJ. 666, 1024) is to the spectrum
of SN 1995E at 10 days after maximum.  The redshift, estimated from broad
supernova features, is z = 0.042, consistent with the photo-z estimate of
the presumed host galaxy in the SDSS database.  The expansion velocity at
the photosphere, derived from the absorption minimum of the Si II 635.5-nm
feature, is about 10000 km/s.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 November 27                 (CBET 2557)              Daniel W. E. Green