Electronic Telegram No. 3314
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 2012gx IN MCG -02-2-72 = PSN J00380175-1351395
     A. J. Drake, S. G. Djorgovski, M. J. Graham, A. Mahabal, and R. Williams,
California Institute of Technology; R. H. McNaught, Australian National
University; J. L. Prieto, Princeton University; M. Catelan, Pontificia
Universidad Catolica de Chile; and S. M. Larson and E. Christensen, Lunar
and Planetary Laboratory, University of Arizona, report the discovery of an
apparent supernova in unfiltered Siding Spring Survey (SSS) images:

 SN       2012 UT         R.A. (2000.0) Decl.      Mag.      Offset
 2012gx   Nov. 18.52    0 38 01.75  -13 51 39.5    14.5     6".9 W, 18".5 N

The variable was designated PSN J00380175-1351395 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012gx based on the
spectroscopic confirmation reported below.  Further CCD magnitudes for 2012gx:
July 19, [18.9 (SSS); Nov. 19.131, 14.8 (R. A. Koff, Bennett, CO, USA; Meade
0.25-m f/10 reflector + Apogee U-47 camera; limiting mag 18.0; position end
figures 01s.73, 39".4; UCAC3 reference stars; image posted at website URL
http://antelopehillsobservatory.org/SNpictures/PSNJ00380175-1351395final.jpg);
23.096, R = 14.8 (J. Brimacombe, Cairns, Australia; position end figures
01s.70, 39".5); 24.225, R = 14.8 (Brimacombe; position end figures 01s.71,
39".5; image posted at http://www.flickr.com/photos/43846774@N02/8221090003/).
Brimacombe's Nov. 23 image is posted at the following website URL:
http://www.flickr.com/photos/43846774@N02/8221090003/.

     N. Morrell, E. Hsiao, C. Contreras, and M. Phillips, Las Campanas
Observatory, Carnegie Supernova Project, report that they obtained an optical
spectrogram (range 370-960 nm) of PSN J00380175-1351395 = SN 2012gx on Nov.
20.05 UT with the Las Campanas 2.5-m du Pont telescope (+ WFCCD), which shows
this to be a type-Ia supernova around 10 days past maximum brightness.
Cross-correlation with a library of supernova spectra using the Supernova
Identification code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) suggests
that 2012gx is a normal type-Ia event at a redshift z = 0.014, with a spectrum
very similar to that of SN 2003cg at 9 days past maximum light.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 November 27                 (CBET 3314)              Daniel W. E. Green