Electronic Telegram No. 2882
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 2011hc = PSN J20121007-1121577
     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
 2011hc   Oct. 23.16   20 12 10.07  -11 21 57.7   16.5       0".8 N

The variable was designated PSN J20121007-1121577 when it was posted on the
Central Bureau's TOCP webpage and is here designated SN 2011hc based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes
(unfiltered unless otherwise noted) for 2011hc:  2010 Nov. 18.10 UT, [19.0
(CSS); 2011 Oct. 26.177, 16.4 (Joseph Brimacombe, Cairns, Australia; position
end figures 10s.11, 56".6; image posted at the following website URL:
http://www.flickr.com/photos/43846774@N02/6290844088/); 29.06, 16.5 (R. A.
Koff, Bennett, CO, USA; Meade 0.25-m f/10 Schmidt-Cassegrain reflector +
Apogee AP-47p CCD camera; position end figures 10s.06, 57".1; UCAC3 reference
stars; image scale 2"/pixel; limiting magnitude 18.4); 29.898, R = 16.7
(Federica Luppi, Varese, Italy, 0.36-m f/7.9 reflector + Bessell R filter;
position end figures 10s.10, 56".4; reference stars from CMC-14 catalogue;
image posted at http://www.astrogeo.va.it/pub/TOCP/PSN_20121007-1121577.jpg).

     G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on
behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm)
of PSN J20121007-1121577 = 2011hc was obtained on Oct. 28 UT by P. Berlind
with the F. L. Whipple Observatory 1.5-m telescope (+ FAST).  Cross-
correlation with a library of supernova spectra using the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows
that 2011hc is a type-Ia supernova near maximum light.  A good fit is found
for the template from the normal type-Ia supernova 2006S at +1 day.  Good
fits can also be found for 1991T-like type-Ia supernovae at a similar epoch.
The velocity of the Si II 635.5-nm feature is estimated to be approximately
8000 km/s, using an estimated redshift of z = 0.0310, measured from host-
galaxy emission lines.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 November 1                  (CBET 2882)              Daniel W. E. Green