Electronic Telegram No. 3117
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 2012ch = PSN J15060254+4125327
     A. J. Drake, S. G. Djorgovski, M. J. Graham, A. Mahabal, 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        2012 UT       R.A. (2000.0) Decl.      Mag.      Offset
 2012ch    May 17.38   15 06 02.54  +41 25 32.7   16.4    1".0 W, 2".1 S

The variable was designated PSN J15060254+4125327 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012ch based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2012ch:  Apr. 1.50 UT, 17.5 (CSS); 18.418, 15.9 (Joseph Brimacombe, Cairns,
Australia; luminance filter; position end figures 02s.57, 31".2; image posted
at website URL http://www.flickr.com/photos/43846774@N02/7230337250/).

     G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on
behalf of the CfA Supernova Group, reports that a spectrum (range 340-740 nm)
of PSN J15060254+4125327 = 2012ch was obtained on May 18 UT by J. Irwin 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 2012ch is a
type-IIP supernova before maximum light.  A good fit is found to the template
of the type-IIP supernova 1999em at four days before maximum.  Prominent
P-Cyg features from Balmer-series lines are present, and the velocity of
H-alpha (measured at the absorption minimum) is 14200 km/s; a redshift of
z = 0.008637 for the presumed host galaxy was used (from 2004 SDSS 3.C).


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 May 23                      (CBET 3117)              Daniel W. E. Green