Electronic Telegram No. 3527
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 2013co = PSN J12555051+3030415
     Tianmeng Zhang, National Astronomical Observatories of China (NAOC);
Xiaofeng Wang, Tsinghua University; and Tianfang Zhang, Beijing 35th Middle
School, report the discovery of an apparent supernova (mag 17.7) on unfiltered
CCD images taken on May 6.54 UT using the 0.6-m NAOC Schmidt telescope in the
course of the THU-NAOC Transient Survey (TNTS).  The new object is located at
R.A. = 12h55m50s.51, Decl. = +30d30'41".5 (equinox 2000.0), which is 0".5 east
and 0".3 north of the faint presumed-host galaxy.  Additional approximate TNTS
magnitudes for the variable:  2013 Apr. 25, 17.9; May 3, 17.8.  Nothing is
visible at this position on  archival images obtained on Jan. 6 (limiting mag
about 20.0) or on a Digitized Sky Survey image from the Palomar Sky Survey
(no bandpass or limiting magnitude provided).  The TNTS images are posted at
URL http://www.thca.tsinghua.edu.cn/~wangxf/TNTS/PSNJ12555051+3030415.png.
The variable was designated PSN J12555051+3030415 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013co based on the
spectroscopic confirmation reported below.

     J. M. Silverman, University of Texas; J. Vinko, University of Szeged; R.
Quimby, Kavli IPMU, University of Tokyo; and J. C. Wheeler, University of
Texas, write that a spectrogram, obtained on May 13.29 UT with the 9.2-m
Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by S.
Rostopchin, shows that PSN J12555051+3030415 = SN 2013co is a luminous type-Ic
supernova.  Correlation with a library of supernova spectra using the
"SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666,
1024) indicates that 2013co is a type-Ic supernova, possibly of the broad-
lined subtype, a few days after maximum brightness.  The host-galaxy recession
velocity is found to be 14907 km/s (from narrow emission lines, and which is
consistent with the Sloan Digital Sky Survey photo-z value), implying that the
absolute magnitude of the supernova is about -19.0 (which is comparable to the
broad-lined type-Ic GRB/SN 1998bw; e.g., Galama 1998, Nature 395, 670), and
the absolute r-band magnitude of the host galaxy is about -16.9 (SDSS).


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 May 14                      (CBET 3527)              Daniel W. E. Green