Electronic Telegram No. 3052
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 2012au IN NGC 4790 = PSN J12545218-1014502
     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;
R. Roy, Aryabhatta Research Institute of Observational Sciences; V. Mohan,
Inter-University Centre for Astronomy and Astrophysics; 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 public images from the Catalina Sky Survey (CSS).

 SN       2012 UT        R.A. (2000.0) Decl.      Mag.      Offset
 2012au   Mar. 14.45   12 54 52.18  -10 14 50.2   13.8    3".5 E, 2".0 N

The variable was designated PSN J12545218-1014502 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012au based on the
spectroscopic confirmation reported below.  Additional magnitudes for 2012au
(unfiltered unless noted otherwise):  Feb. 22.46 UT, [19.4 (CSS); Mar. 2.36,
18.2 (CSS); 15.165, 13.5 (Howerton, 0.3-m telescope); 15.319, 13.6 (Joseph
Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K
camera + luminance filter at the New Mexico Skies Observatory near Mayhill,
NM, U.S.A.; position end figures 52s.22, 50".8; image posted at website URL
http://www.flickr.com/photos/43846774@N02/6839966426/); 15.335, 13.2 (L.
Elenin, Lyubertsy, Russia, and I. Molotov, Moscow; images remotely taken at
ISON-NM Observatory near Mayhill with a 0.45-m f/2.8 telescope; position end
figures 52s.25 +/- 0".2, 50".6 +/- 0".1; NOMAD reference stars; image posted
at URL http://spaceobs.org/images/TOCP/PSNJ12545218-1014502-20120315.png;
limiting mag about 20.0); 16.457, 13.0 (R. A. Koff, Bennett, CO, USA; Meade
0.25-m f/10 reflector + Apogee AP-47p camera; limiting mag 17.4; position end
figures 52s.16, 50".7).

     J. M. Silverman, S. B. Cenko, A. A. Miller, P. E. Nugent, and A. V.
Filippenko, University of California, Berkeley, report that inspection of a
CCD spectrum (range 330-1000 nm), obtained on Mar. 15 UT with the 10-m Keck I
telescope (+ LRIS), confirms the findings of Soderberg et al. (see website
URL http://www.astronomerstelegram.org/?read=3968) and shows that PSN
J12545218-1014502 = 2012au is a supernova of type Ib with very well-developed
He I lines, likely near maximum brightness.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 March 18                    (CBET 3052)              Daniel W. E. Green