[IAUC] CBET 2833: 20110929 : SUPERNOVA 2011ga IN PGC 69458 = PSN J22402742+0311580

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                                                  Electronic Telegram No. 2833
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 2011ga IN PGC 69458 = PSN J22402742+0311580
     A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams,
California Institute of Technology; J. L. Prieto, Carnegie Observatories;
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
 2011ga   Sep. 18.25   22 40 27.42  + 3 11 58.0   17.3    18".2 W, 7".4 N

The new object was designated PSN J22402742+0311580 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2011ga based on the
spectroscopic report below.  Additional CCD magnitudes for 2011ga (unfiltered
unless noted otherwise:  July 2.38 UT, [19.3 (CSS); Sept. 19.179, 16.5
(Joseph Brimacombe, Cairns, Australia; infrared filter, wavelength > 700 nm;
image posted at URL http://www.flickr.com/photos/43846774@N02/6177998402/);
19.320, 17.2 (Brimacombe; position end figures 27s.38, 58".9; image posted at
website URL http://www.flickr.com/photos/43846774@N02/6168832131/).

     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 of PSN J22402742+0311580 = SN 2011ga,
obtained on Sept. 24.91 UT, suggests that it is a type-Ia supernova observed
close to B-band maximum.  The velocity of the ejected material, as deduced
from the position of the minimum of the Si II lines, is about 10600 km/s.

     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 J22402742+0311580 = 2011ga was obtained on Sept. 27 UT by Marion 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 the object is a
type-Ia supernova a few days after maximum light.  The best-fit template
spectrum is that of SN 2003du at +2 days.  The velocity of the Si II 635.5-nm
feature is estimated to be approximately 10800 km/s, using the SNID estimated
redshift of z = 0.040.


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 2833)              Daniel W. E. Green