Electronic Telegram No. 3078
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 2012bn IN IC 1133 = PSN J15411344+1534222
     T. Puckett and J. Newton report the discovery of an apparent supernova
(mag 17.9) on an unfiltered CCD image (limiting mag 19.2) taken with a 0.40-m
reflector at Portal, AZ, U.S.A., on Mar. 27.455 UT in the course of the
Puckett Observatory Supernova Search.  The new object is located at R.A. =
15h41m13s.44, Decl. = +15o34'22".2 (equinox 2000.0), which is 19".2 east and
1".0 south of the center of IC 1133 (= UGC 9973).  The discoverers posted an
image at website URL http://www.possdata.com/PSNJ15411344+1534222.jpg.  The
variable was designated PSN 15411344+1534222 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012bn based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2012bn (unfiltered unless noted otherwise):  Feb. 23, [18.9 (Puckett); Mar.
28.315, 17.5 (Puckett); 28.423, 17.3 (R. A. Koff, Bennett, CO, USA; Meade
0.25-m f/10 reflector + Apogee AP-47p camera; limiting magnitude 19.5;
position end figures 13s.25, 21".6; UCAC3 reference stars); 28.46, 18.5
(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 13s.41, 21".9; image posted at
website URL http://www.flickr.com/photos/43846774@N02/6879057750/); 29.028,
17.3 (Massimiliano Martignoni, Magnago, Italy; 25-cm f/10 Schmidt-Cassegrain
reflector + KAF0261E CCD chip; V magnitude noted; position end figures
13s.20, 21".0).

     E. Cappellaro, A. Pastorello, L. Tomasella, S. Benetti, M. Fiaschi,
P. Ochner, M. Turatto, and S. Valenti, Osservatorio Astronomico di Padova,
Istituto Nazionale di Astrofisica, report that a spectrogram of PSN
J15411344+1534222 = SN 2012bn, obtained on Mar. 28.13 with the Asiago 1.82-m
Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 2.4 nm), shows a
blue continuum with relatively broad, P-Cyg H lines -- similar to spectra of
young type-II supernovae.  In fact, adopting for the host galaxy a redshift
z = 0.013513 (Falco et al. 1999, PASP 111, 438; via NED), a comparison with a
library of supernovae spectra via GELATO (Harutyuyan et al. 2008, A.Ap. 488,
383) shows that it is a type-II event several days after explosion.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 March 29                    (CBET 3078)              Daniel W. E. Green