[IAUC] CBET 3734: 20131205 : SUPERNOVA 2013gs IN UGC 5066 = PSN J09310887+4623054

Mie Dic 4 20:43:24 ART 2013

                                                  Electronic Telegram No. 3734
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 en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2013gs IN UGC 5066 = PSN J09310887+4623054
     Tianmeng Zhang, National Astronomical Observatories of China (NAOC);
Xiaofeng Wang, Li Zhou, Jun Mo, and Juncheng Chen, Tsinghua University (THU);
and Xu Dong, Dark Cosmology Centre, report the discovery of an apparent
supernova (mag 17.3) on unfiltered CCD images taken on Nov. 29.84 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. = 9h31m08s.87, Decl. = +46d23'05".4
(equinox 2000.0), which is 15".0 east and 2".0 north of the center of the
galaxy UGC 5066.  Nothing is visible at this position on a Digitized Sky
Survey image from the Palomar Sky Survey.  The TNTS images are posted at the
URL http://www.thca.tsinghua.edu.cn/~wangxf/TNTS/PSNJ09310887+4623054.png.
The variable was designated PSN J09310887+4623054 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013gs based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2013gs:  Nov. 25.80, [20.0 (TNTS); Dec. 1.064, 17.1 (Federica Luppi and Luca
Buzzi, Varese, Italy; position end figures 08s.82, 05".4); 1.451, 16.9 (L.
Elenin, Lyubertsy, Russia, and I. Molotov, Moscow; remotely taken with a
0.4-m f/3 telescope located at the ISON-NM observatory near Mayhill, NM, USA;
position end figures 08s.81 +/- 0".10, 04".9 +/- 0".11; UCAC-4 reference
stars; limiting red magnitude about 18.9; image posted at website URL
http://spaceobs.org/images/TOCP/PSNJ09310887+4623054-20131201.png); 3.114,
16.8 (Massimiliano Martignoni, Magnago, Italy; 0.25-m f/10 Schmidt-Cassegrain
reflector; position end figures 08s.84, 05".4); 4.945, 16.2 (Gianluca Masi,
Francesca Nocentini, and Patrick Schmeer; remotely using a 43-cm telescope
near Ceccano, Italy; position end figures 08s.83, 05".3).

     J.-J. Zhang, Yunnan Astronimical Observatory (YNAO); and X.-F. Wang,
Tsinghua University, report on an optical spectrogram (range 350-890 nm) of
PSN J09310887+4623054 = SN 2013gs that was obtained on Dec. 1.81 UT with the
2.4-m telescope (+ YFOSC) at the LiJiang Gaomeigu Station of YNAO.  The
spectrum is consistent with a very young type-Ia supernova.  Cross-correlation
with a library of supernova spectra using the "Supernova Identification" code
(SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2013gs matches with
SN 2005cf at 10 days before maximum light.  Adopting for the host galaxy (UGC
5066) a recession velocity of 5063 km/s (after Falco et al. 1999, PASP 111,
438), Zhang and Wang measure the velocity of the Si II 635.5-nm absorption
feature to be about 17500 km/s, and a velocity of Ca II infrared triplet
absorptions to be about 27000 km/s.


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

                         (C) Copyright 2013 CBAT
2013 December 5                  (CBET 3734)              Daniel W. E. Green