Electronic Telegram No. 2839
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 2011gg = PSN J00462108-0909277
     A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams,
California Institute of Technology; J. L. Prieto, Princeton University; M.
Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M.
Larson, Lunar and Planetary Laboratory, University of Arizona; and E.
Christensen, Gemini Observatory, report the discovery of an apparent supernova
in unfiltered Catalina Sky Survey (CSS) images:

 SN       2011 UT        R.A. (2000.0) Decl.      Mag.      Offset
 2011gg   Sep. 20.32   00 46 21.08  - 9 09 27.7   17.6    4".5 W, 1".1 S

This variable was designated PSN J00462108-0909277 when it was posted on the
Central Bureau's TOCP webpage and is here designated SN 2011gg based on the
spectroscopic report below.  Further unfiltered CCD magnitudes for 2011gg:
Sept. 24.34 UT, 17.4 (CSS); 27.407, 16.9 (Joseph Brimacombe, Cairns, Australia;
position end figures 21s.05, 28".6; image posted at the following website URL:
http://www.flickr.com/photos/43846774@N02/6191346245/).

     S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio
Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello,
Dipartimento di Astronomia, Universita di Padova, on behalf of a larger
collaboration, report that a spectrogram (range 360-810 nm; resolution 2.2 nm)
of PSN J00462108-0909277 = SN 2011gg, obtained on Sept. 26.01 UT, suggests
that it is a 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) suggests a normal type-Ia supernova about one week
before the B-band maximum at a redshift z = 0.055.  The expansion velocity
derived from the Si II 635.5-nm minimum is then about 10500 km/s.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 September 29                (CBET 2839)              Daniel W. E. Green