Electronic Telegram No. 2572
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 2010kn
     A. Romadan and W. Zheng, University of Michigan; J. Vinko, University of
Szeged; R. Quimby, California Institute of Technology; 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 18.5) in unfiltered images taken on Dec. 2.20 UT
with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory.  The new object,
which was observed again on Dec. 3.19 at mag about 18.6, is located at R.A. =
11h50m17s.04, Decl. = +43o57'47".0 (equinox 2000.0; uncertainty about 1"),
which is 0".2 east and 1".6 north of the center of the presumed host galaxy
(SDSS J115017.02+435745.4).  A spectrum, obtained on Dec. 5.45 with the 9.2-m
Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by M. Shetrone,
shows that 2010kn is a type-Ia supernova, a few days before maximum light.
The spectrum contains the Si II 635.5-nm line and several other characteristic
type-Ia-supernova features.  According to SNID (Blondin and Tonry 2007, ApJ.
666, 1024), the spectrum most resembles those of SN 2002er (at 9.4 days before
maximum) and SN 2000E (at 2.5 days before maximum).  The median redshift
estimate is z = 0.073, in good agreement with the spectroscopic redshift of
the galaxy designated SDSS J115017.02+435745.4 (z = 0.071) via the Sloan
Digital Sky Survey.  Adopting this redshift, the velocity (from the absorption
minimum of the Si II 635.5-nm feature) is 11000 km/s.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2010 CBAT
2010 December 8                  (CBET 2572)              Daniel W. E. Green