Electronic Telegram No. 3738
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 2013gu = PSN J01463827+0413244
     Denis Denisenko, Sternberg Astronomical Institute, reports the discovery
by Sergey Shurpakov of an apparent supernova (mag 15.5) on 60-s unfiltered CCD
survey images obtained on Dec. 5.751 UT with the 0.40-m f/2.5 MASTER reflector
at Kislovodsk.  The new object is located at R.A. = 1h46m38s.27, Decl. =
+4d13'24".4 (equinox 2000.0), which is 0".5 east and 10" south of the center
of the presumed host galaxy.  The variable was designated PSN J01463827+0413244
when it was posted at the Central Bureau's TOCP webpage and is here designated
SN 2013gu based on the spectroscopic confirmation reported below.  Additional
CCD magnitiudes for 2013gu:  Dec. 5.858, 16.8 (Gianluca Masi, Francesca
Nocentini, and Patrick Schmeer; remotely using a 43-cm telescope near Ceccano,
Italy; position end figures 38s.32, 24".3); 7.916, 16.5 (F. Luppi, M. Calabro,
A. Medda, and A. Piovanelli, Varese, Italy; 0.38-m f/6.8 reflector; position
end figures 38s.30, 24".4; reference stars from CMC-14 catalogue; image posted
at website URL http://www.astrogeo.va.it/pub/TOCP/PSN_P12652941.jpg).

     W. Zheng, P. L. Kelly, K. I. Clubb, and A. V. Filippenko, University of
California, Berkeley, report that a CCD spectrogram (range 350-1000 nm) of PSN
J01463827+0413244 = SN 2013gu was obtained on Dec. 6.5 UT with the Shane 3-m
reflector (+ Kast spectrograph) at Lick Observatory.  The spectrum shows a
blue continuum and weak, broad hydrogen Balmer lines having P-Cyg profiles,
indicating that the object is a young type-IIP supernova.  Weak He I 587.6-nm
is also present.  Cross-correlation with a library of supernova spectra using
the "SuperNova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666,
1024) yields a good match with several type-IIP supernovae at a few days after
explosion.  The redshift derived from SNID is about 0.02, consistent with the
redshift of 0.0177 from Ann et al. (1998, Ap.J. 496, 39; via NED).

     L. Tomasella, L. Tartaglia, P. Ochner, A. Pastorello, S. Benetti, E.
Cappellaro, N. Elias-Rosa, and M. Turatto, Osservatorio Astronomico di Padova,
Istituto Nazionale di Astrofisica, report that a spectrogram of PSN
J01463827+0413244 = 2013gu, obtained on Dec. 6.84 UT with the Asiago 1.82-m
Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 1.3 nm), shows that
the object is a very young type-II supernova.  Broad and shallow P-Cyg H-alpha,
H-beta, and He I 587.6-nm lines are clearly detected.  Adopting for the host
galaxy (PGG 1265294) a redshift z = 0.0177 (Ann et al. 1998, Ap.J. 496, 39;
via NED), a good fit is found with the type-IIP supernova 1999gi (Leonard et
al. 2002, A.J. 124, 2490) a few days after the explosion.  The Asiago
classification spectra are posted at website URL http://graspa.oapd.inaf.it.
The classification was made via GELATO (Harutyunyan et al. 2008, A.Ap. 488,
383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024).

     Xulin Zhao, Jun Mo, and Xiaofeng Wang, Tsinghua University (THU); and
Tianmeng Zhang, National Astronomical Observatories of China (NAOC), report
on an optical spectrogram (range 375-860 nm) of PSN J01463827+0413244 = SN
2013gu that was obtained on Dec. 6.60 UT with the 2.16-m telescope (+ BFOSC)
at the Xinglong Station of NAOC.  The spectrum is consistent with a type-IIP
supernova around maximum light.  Broad H I 656.3-nm, H I 486.1-nm, and He
I 587.6-nm lines with P-Cyg profiles can be seen in the spectrum.  Cross-
correlation with a library of supernova spectra using the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows
that it matches with SN 2004et at one day after maximum brightness.  Adopting
for the host galaxy (PGC 1265294) a recession velocity of 5319 km/s (Zabludoff
and Mulchaey 1998, A.J. 130, 1037), they measure a blue-shifted velocity of
the H I 656.3-nm, H I 486.1-nm, and He I 587.6-nm absorption minima to be
about 11300 km/s, 9700 km/s, and 10100 km/s, respectively.


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

                         (C) Copyright 2013 CBAT
2013 December 8                  (CBET 3738)              Daniel W. E. Green