[IAUC] CBET 2751: 20110628 : SUPERNOVA 2011ds = PSN J20022093-2013134

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                                                  Electronic Telegram No. 2751
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 2011ds = PSN J20022093-2013134
     S. Howerton, Arkansas City, KS, U.S.A.; 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; R. H. McNaught and G. Garradd, Australian National
University; 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 public images from the Catalina Sky
Survey; it was confirmed in images obtained with the Siding Spring Survey
(SSS).

 SN       2011 UT       R.A. (2000.0) Decl.      Mag.      Offset
 2011ds   May 13.42   20 02 20.93  -20 13 13.4   16.6    6" W, 17" N

The variable was designated PSN J20022093-2013134 when posted at the Central
Bureau's TOCP webpage and is here designated SN 2011ds based on the
spectroscopic confirmation that is detailed below.  Further magnitudes for
2011ds:  Apr. 11.74 [19.0 (SSS); May 14.69, 16.6 (SSS); 15.721, 16.6 (Joseph
Brimacombe, Coral Towers Observatory, Cairns, Australia, 30-cm telescope +
STL6K camera + red filter; position end figures 20s.92, 12".8).  Brimacombe's
image is posted at URL http://www.flickr.com/photos/43846774@N02/5724709574/.

     S. Valenti and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio
Astronomico di Padova, on behalf of a larger collaboration, report that a
low-signal-to-noise spectrogram (range 330-750 nm; resolution 1.5 nm) of PSN
J20022093-2013134 = SN 2011ds, obtained on June 26.43 UT with the European
Southern Observatory's New Technology Telescope (+ EFOSC2), is consistent with
that of a type-II supernova.  The spectrum indeed shows strong hydrogen
H-alpha at 669.1 nm, mainly in emission with a full-width-at-half-maximum
of about 7400 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      superseded by text appearing later in the printed IAU Circulars.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 June 28                     (CBET 2751)              Daniel W. E. Green