[IAUC] CBET 3130: 20120530 : SUPERNOVA 2012cp IN UGC 8713 = PSN J13470168+3353360

Mie Mayo 30 06:49:40 ART 2012

                                                  Electronic Telegram No. 3130
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 2012cp IN UGC 8713 = PSN J13470168+3353360
     L. Cox, J. Newton, and T. Puckett report the discovery of an apparent
supernova (mag 16.1) on unfiltered CCD images (limiting mag 19.1) taken with a
0.40-m reflector at Portal, AZ, U.S.A., on May 23.1914 UT in the course of the
Puckett Observatory Supernova Search.  The new object is located at R.A. =
13h47m01s.68, Decl. = +33o53'36".0 (equinox 2000.0), which is 6".7 east and
1".2 south of the center of UGC 8713.  The variable was designated PSN
J13470168+3353360 when it was posted at the Central Bureau's TOCP webpage and
is here designated SN 2012cp based on the spectroscopic confirmation reported
below.  Additional CCD magnitudes for 2012cp:  Apr. 5, [19.2 (Puckett); May
24.235, 16.0 (R. Post, Trenton, ME, U.S.A.; 0.43-m reflector; limiting mag
19.2; via Puckett); 25.303, 16.1 (J. Brimacombe, Cairns, Australia; luminance
filter; position end figures 01s.71, 35".8; image posted at website URL
http://www.flickr.com/photos/43846774@N02/7270261360/); 25.921, 15.3 (G.
Cortini, Predappio, Italy; Celestron 14 telescope + unfiltered SXVR-H9
camera); 28.863, R_c = 15.3 (M. Martignoni, Magnago, Italy; 25-cm reflector;
position end figures 01s.69, 35".6; PPMXL reference stars); 29.026, 16.2
(Federica Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8 reflector;
position end figures 01s.72, 35".6; reference stars from CMC-14 catalogue;
image posted at URL http://www.astrogeo.va.it/pub/TOCP/PSN_U8713.jpg).

     T.-M. Zhang and C.-J. Wu, National Astronomical Observatories of China
(NAOC); and X.-F. Wang, Tsinghua Center for Astrophysics (THCA), Tsinghua
University report on an optical spectrogram (range 400-700 nm) of PSN
J13470168+3353360 that was obtained on May 25.7 UT with the 2.16-m telescope
(+ BFOSC) at Xinglong Station of the NAOC.  The spectrum is blue and is
consistent with a type-Ia supernova a few days before maximum light.
Adopting a recession velocity 4956 km/s for the host galaxy, UGC 8713
(Freudling 1995, A.Ap. Suppl. 112, 429; via NED), the velocity of the Si II
635.5-nm absorption feature is measured to be about 12300 km/s.

     D. Milisavljevic, Harvard-Smithsonian Center for Astrophysics, reports
that low-dispersion optical spectra (range 380-680 nm) of PSN J13470168+3353360
= SN 2012cp, obtained on May 28.3 UT with the 2.4-m Hiltner telescope (+ OSMOS)
at MDM Observatory, show it to be a type-Ia supernova.  Cross-correlation with
a library of supernova spectra using the "Supernova Identification" code (SNID;
Blondin and Tonry 2007, Ap.J. 666, 1024) shows matches with normal type-Ia
events a few days before maximum light.  The best match is with SN 1990N at -6
days. After correcting for the host redshift of z = 0.01635, as determined
from narrow Na I D absorption, the velocity of the minimum of the Si II
635.5-nm feature is estimated to be approximately 11300 km/s.


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

                         (C) Copyright 2012 CBAT
2012 May 30                      (CBET 3130)              Daniel W. E. Green