Electronic Telegram No. 3740
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 2013gw = PSN J13224838+3330207
     Vladimir Lipunov reports the discovery by Sergey Shurpakov of a possible
supernova (mag 16.5) on three unfiltered CCD images (limiting mag 18.2)
obtained with the auto-detection system of the MASTER II 40-cm telescope (+
Apogee Alta U16m camera; field-of-view 2 x 4 square degrees) at the MASTER-Amur
observatory (see website URL http://observ.pereplet.ru) on Nov. 28.887 UT.
The new object is located at R.A. = 13h22m48s.38, Decl. = +33d30'20".7 (equinox
2000.0), which is 7" east and 11" south of the center of PGC 2033541.  The
variable was designated PSN J13224838+3330207 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013gw based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2013gw:  Nov. 29.475, 17.1 (L. Elenin, Lyubertsy, Russia, and I. Molotov,
Moscow; images remotely taken with a 0.4-m f/3 telescope at the ISON-NM
Observatory near Mayhill, NM, USA; limiting mag about 19.4; position end
figures 48s.36 +/- 0".12, 21".4 +/- 0".16; UCAC-4 reference stars; image posted
at URL http://spaceobs.org/images/TOCP/PSNJ13224838+3330207-20131129.png);
Dec. 1.173, 17.2 (Federica Luppi and Luca Buzzi, Varese, Italy; position end
figures 48s.36, 21".4  and magnitude 17.2. Image posted at website URL
http://www.astrogeo.va.it/pub/TOCP/PSN_P2033541.jpg); 5.124, 17.3 (Gianluca
Masi, Francesca Nocentini, and Patrick Schmeer; remotely using a 43-cm
telescope near Ceccano, Italy; position end figures 48s.35, 21".6).

     P. Ochner, L. Tomasella, L. Tartaglia, A. Pastorello, S. Benetti, E.
Cappellaro, N. Elias-Rosa, and M. Turatto, Osservatorio Astronomico di Padova,
Istituto Nazionale di Astrofisica, report that an optical spectrogram (range
340-820 nm; resolution 1.3 nm) of PSN J13224838+3330207 = SN 2013gw, obtained
on Dec. 7.21 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC), shows it
to be normal type-Ia supernova.  Adopting for the host galaxy (PGC 2033541) a
redshift z = 0.0387 (Sloan Digital Sky Survey 2006, via NED) a good match is
found with several type-Ia supernovae at a phase of about two weeks after
maximum light.  The Asiago classification spectra are posted at website URL
http://sngroup.oapd.inaf.it; classification was made via GELATO (Harutyunyan
et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666,
1024).


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 3740)              Daniel W. E. Green