Electronic Telegram No. 3726
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 2013gm IN PGC 35745 = PSN J11342116+1539331
     Tianmeng Zhang, National Astronomical Observatories of China (NAOC);
Xiaofeng Wang, Li Zhou, Jun Mo, and Juncheng Chen, Tsinghua University (THU);
and Xu Zhou, NAOC, report the discovery of an apparent supernova (mag 17.5) on
unfiltered CCD images taken on Nov. 20.85 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. = 11h34m21s.16, Decl. = +15d39'33".1 (equinox
2000.0), which is 0".6 west and 3".9 south of the center of the galaxy MCG
+03-30-7 = PGC 35745.  Nothing is visible at this position on a Digitized Sky
Survey image from the Palomar Sky Survey.  The TNTS images are posted at URL
http://www.thca.tsinghua.edu.cn/~wangxf/TNTS/PSNJ11342116+1539831.png.  The
variable was designated PSN J11342116+1539331 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013gm based on the
spectroscopic confirmation reported below.  Additional unfiltered CCD
magnitudes for 2013gm:  Jan. 12, [20.0 (TNTS); Nov. 26.481, 17.8 (Joseph
Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope +
STXL-6303 camera at the New Mexico Skies observatory near Mayhill, NM, USA;
position end figures 21s.14, 32".5; image posted at website URL
http://www.flickr.com/photos/43846774@N02/11085277705/).

     J.-J. Zhang, Yunnan Astronomical Observatory (YNAO); and X.-F. Wang,
Tsinghua University, report on an optical spectrogram (range 360-820 nm) of
PSN J11342116+1539331 = SN 2013gm that was obtained on Nov. 21.92 UT with the
2.4-m telescope (+ YFOSC) at the LiJiang Gaomeigu Station of YNAO.  The
spectrum is consistent with a type-IIP supernova at around maximum light.
Cross-correlation with a library of supernova spectra using the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows
that 2013gm matches with SN 1999em at -2 days with respect to maximum light.
The redshift of the host galaxy is estimated as 0.0173 from the narrow
emission line.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 November 28                 (CBET 3726)              Daniel W. E. Green