[IAUC] CBET 2764: 20110714 : SUPERNOVA 2011eb IN NGC 782 = PSN J01573658-5748008

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                                                  Electronic Telegram No. 2764
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 2011eb IN NGC 782 = PSN J01573658-5748008
     L. A. G. Monard, Calitzdorp, Western Cape, South Africa, reports his
discovery of an apparent supernova (mag 15.2) on several unfiltered CCD images
taken on July 9.131 UT at the Klein Karoo Observatory.  The new object is
located at R.A. = 1h57m36s.58, Decl. = -57d48'00".8 (equinox 2000.0), which is
29" west and 34" south of the core of the SBb-type galaxy NGC 782.  The
variable was designated PSN J01573658-5748008 when posted on the Cenetral
Bureau's TOCP webpage and is here designated SN 2011eb based on the
spectroscopic reports below.  Nothing is visible at this position on the
Digitized Sky Survey (limiting red mag 20.5).  Additional magnitudes for
2011eb:  May 29.147, [18.7 (Monard); July 9.771, 16.3 (Joseph Brimacombe,
Cairns, Australia; red filter; position end figures 36s.65, 47'59".3); 10.125,
15.3 (Monard); 11.804, 15.1 (Brimacombe; red filter).  One of Brimacombe's
images from July 9 is posted at the following website URL:
http://www.flickr.com/photos/43846774@N02/5920090860/, while his image from
July 11 is posted at  http://www.flickr.com/photos/43846774@N02/5930061424/.

     D. Milisavljevic and R. Fesen, Dartmouth College; K. Nordsieck, University
of Wisconsin; and T. Pickering and D. O'Donoghue, South African Astronomical
Observatory, on behalf of a larger SALT Commissioning Team, report that
low-dispersion spectra (range 320-890 nm), obtained on July 10.1 UT with the
10-m SALT telescope (+ RSS), show PSN J01573658-5748008 = SN 2011eb to be 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) shows matches with normal type-Ia events around maximum light.
After correcting for the recession velocity 6098 km/s (Wong et al. 2006,
MNRAS 371, 1855; via NED) of its host galaxy NGC 782, the velocity of the
Si II 635.5-nm feature is estimated to be approximately 11000 km/s.

     J. Parrent, Dartmouth College and Las Cumbres Observatory; with D. A.
Howell, R. C. Thomas, P. E. Nugent, and M. Sullivan, write that a CCD spectrum
(range 350-900 nm) of PSN J01573658-5748008 = SN 2011eb was taken with the
Gemini South telescope on July 13 UT, indicating that this object is a type-Ia
supernova within a few days of maximum light, based on comparisons to other
spectra using "Superfit" (Howell et al. 2005, Ap.J. 634, 1190); the Doppler
velocity of the Si II 635.5-nm absorption feature is about 11300 km/s,
assuming a host-galaxy redshift of z = 0.02.


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

                         (C) Copyright 2011 CBAT
2011 July 14                     (CBET 2764)              Daniel W. E. Green