[IAUC] CBET 3095: 20120429 : SUPERNOVA 2012by IN UGC 8335 = PSN J13152890+6207478

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 3095
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 2012by IN UGC 8335 = PSN J13152890+6207478
     D. Rich, Hampden, ME, USA, reports his discovery of an apparent supernova
(mag about 17.6) on unfiltered CCD frames (limiting mag 19.0) taken with a
0.41-m reflector on Apr. 25.213 UT, with a confirming image obtained on Apr.
26.143 (mag about 17.5).  The new object is located at R.A. = 13h15m28s.90,
Decl. = +62o07'47".8 (equinox 2000.0), which is about 13".8 west and 3".0
north of the center of the westernmost galaxy of the pair designated UGC 8335.
Nothing is visible at this position on a CCD frame taken by Rich on Mar.
22.192 (limiting mag about 19.0) or on Palomar Digital Sky Survey images from
1997 June 25 (limiting red mag about 20.5) and 1995 Apr. 23 (limiting blue
mag about 21.0).  The variable was designated PSN J13152890+6207478 when it
was posted at the Central Bureau's TOCP webpage and is here designated SN
2012by based on the spectroscopic confirmation reported below.  Vitali Nevski
(Vitebsk, Belarus) obtained CCD images of 2012?? on Apr. 26.813 with a 0.3-m
reflector that yield magnitude R = 18.1 and position end figures 28s.90,
47".9 (reference stars from the UCAC-3 catalogue).

     L. Tomasella, P. Ochner, A. Siviero, S. Benetti, E. Cappellaro, A.
Pastorello, M. Turatto, and S. Valenti, Osservatorio Astronomico di Padova,
Istituto Nazionale di Astrofisica, report that a spectrogram of PSN
J13152890+6207478 = SN 2012by, obtained on Apr. 27.88 UT with the Asiago
1.82-m Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 2.4 nm),
indicates that this is a type-II supernova.  Broad P-Cyg lines of H and He I
587.6-nm are clearly detected.  Adopting for the host galaxy (UGC 8335) a
redshift z = 0.0308 (Kim et al. 1995, Ap.J. Suppl. 98, 129; via NED database),
the comparison with a library of supernovae spectra via GELATO (Harutyuyan et
al. 2008, A.Ap. 488, 383) shows that 2012by is similar to SN 1996as at a few
days 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 April 29                    (CBET 3095)              Daniel W. E. Green