[IAUC] CBET 3308: 20121125 : SUPERNOVA 2012gr = PSN J03385564+1649435

Sab Nov 24 22:29:56 ART 2012

                                                  Electronic Telegram No. 3308
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 2012gr = PSN J03385564+1649435
     Pavel Balanutsa, Sternberg Astronomical Institute, reports the discovery
of an apparent supernova (mag 18.0) on seven unfiltered images (limiting mag
19.7) taken on Nov. 12.969 UT with the MASTER-Kislovodsk auto-detection system.
The new object is located at R.A. = 3h38m55s.64, Decl. = +16d49'43".5 (equinox
2000.0), which is 1".3 east and 21".8 north of a nearby galaxy (it is also
3".2 away from a galaxy in the Sloan Digital Sky Survey having stated red mag
22.5).  The discovery and reference images are posted at the following website
URL:  http://master.sai.msu.ru/static/OT/033855.64164943.5_1.png.  The
variable was designated PSN J03385564+1649435 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012gr based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2012gr:  Nov. 14.160, 19.0 (R. A. Koff, Bennett, CO, USA; Meade 0.25-m f/10
reflector + Apogee U-47 camera; limiting magnitude 20.7; position end figures
55s.66, 42".1; UCAC3 reference stars; image posted at website URL
http://antelopehillsobservatory.org/SNpictures/PSNJ03385564+1649435final.jpg);
14.209, 19.1 (Joseph Brimacombe, Cairns, Australia; luminance filter; position
end figures 55s.69, 43".0); 14.938, 18.4 (Joel Nicolas, Vallauris, France;
0.41-m f/3.3 reflector; position end figures 55s.71, 42".5; red magnitude
stated); 17.037, 19.0 (Federica Luppi and Luca Buzzi, Varese, Italy; position
end figures 55s.71, 42".7).  Brimacombe's image is posted at website URL
http://www.flickr.com/photos/43846774@N02/8192648676/; that of Luppi and
Buzzi is posted at URL http://www.astrogeo.va.it/pub/TOCP/PSN_P1517827.jpg.

     T.-W. Chen, R. Kotak, and M. Fraser, Queen's University, Belfast, report
that a spectrogram (range 330-975 nm; resolution about 1000) of PSN
J03385564+1649435 = SN 2012gr was obtained on Nov. 22.09 UT with the 4.2-m
William Herschel Telescope (+ ISIS).  SN 2012gr shows strong P-Cyg profiles in
H-alpha, the Ca II near-infrared triplet, and absorption from Na D.  Cross-
correlation with a library of supernova spectra via the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows
that SN 2012gr resembles a number of type-IIP supernovae such as SN 2004et
during the photospheric phase, at least 2-3 weeks into the plateau.


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

                         (C) Copyright 2012 CBAT
2012 November 25                 (CBET 3308)              Daniel W. E. Green