Electronic Telegram No. 3102
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 2012cb IN UGC 3302 = PSN J05281795+7639559
     Giancarlo Cortini, Predappio, Italy, reports the discovery of an apparent
supernova (mag 17.5) on several unfiltered CCD images (limiting mag about 19.0)
taken with a Celestron C14 telescope (+ SXVRH9 camera) on Apr. 27.87 UT.  The
new object is located at R.A. = 5h28m17s.95, Decl. = +76d39'55".9 (equinox
2000.0), which is 18" west and 6" north of the center of UGC 3302.  Nothing
is visible at this position on Palomar Sky Survey red and blue plates.  The
variable was designated PSN J05281795+7639559 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012cb based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2012cb (unfiltered unless noted otherwise):  Mar. 1.90 and 27.85, [19.0
(Cortini); Apr. 28.138, 18.0 (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 17s.71, 55".1; 29.142, 17.8 (L. Elenin, Lyubertsy, Russia, and I.
Molotov, Moscow, Russia; remotely taken at ISON-NM Observatory near Mayhill,
NM, USA, with a 0.45-m f/2.8 telescope; position end figures 18s.14 +/- 0".1,
55".7 +/- 0".09, NOMAD reference stars; limiting mag about 20.4; image posted
at URL http://spaceobs.org/images/TOCP/PSNJ05281795+7639559-20120429.png);
May 3.882, 18.1 (Federica Luppi and Luca Buzzi, Varese, Italy, 0.38-m f/6.8
reflector; position end figures 17s.78, 55".4; reference stars from PPMXL
catalogue; image posted at http://www.astrogeo.va.it/pub/TOCP/PSN_U3302.jpg).

     S. Benetti, A. Pastorello, L. Tomasella, P. Ochner, E. Cappellaro, M.
Turatto, and S. Valenti, Osservatorio Astronomico di Padova, Istituto
Nazionale di Astrofisica; and A. Harutyunyan, Telescopio Nazionale Galileo
(TNG), report that a spectrogram of PSN J05281795+7639559 = SN 2012cb,
obtained on May 5.90 UT with the TNG (+ DOLORES; range 340-800 nm; resolution
1.4 nm), indicates that this is a type-II-plateau supernova.  Broad P-Cyg
lines of H are clearly detected.  Adopting for the host galaxy (UGC 3302) a
redshift z = 0.013923 (de Vaucouleurs et al. 1991, RC3; via NED database), a
comparison with a library of supernovae spectra via GELATO (Harutyuyan et al.
2008, A.Ap. 488, 383) shows that 2012cb is very similar to SN 1999gi (Leonard
et al. 2002, A.J. 124, 2490) at about three weeks after the explosion.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 May 8                       (CBET 3102)              Daniel W. E. Green