[IAUC] CBET 3306: 20121124 : SUPERNOVA 2012gp IN PGC 75651 = PSN J06200624-6457085

Sab Nov 24 13:10:56 ART 2012

                                                  Electronic Telegram No. 3306
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 2012gp IN PGC 75651 = PSN J06200624-6457085
     Stuart Parker, Oxford, Canterbury, New Zealand, reports his discovery of
an apparent supernova (red mag 17.4) on a 35-s unfiltered CCD image (limiting
mag 19.0) taken on Oct. 10.510 UT with a 30-cm Astro-Tech AT12RC Ritchey-
Chretien astrograph (+ ST10 camera) at his Parkdale Observatory in the course
of the Backyard Observatory Supernova Search.  The new object is located at
R.A. = 6h20m06s.24, Decl. = -64d57'08".5 (equinox 2000.0; reference stars
from USNO-B and UCAC3 catalogues), which is 8" east and 1" south of the
nucleus of the galaxy PGC 75651.  Nothing is visible at this postion on
Digitized Sky Survey red and infrared images (limiting red magnitude > 19).
The variable was designated PSN J06200624-6457085 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012gp based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2012gp:  Sept. 27.700, [18.5 (Parker); Oct. 14.374, 17.4 (Parker; 35-cm
Celestron C14 reflector + ST10 camera; limiting mag 18.5); 19.570, 17.1
(Parker; instrumentation as on Oct. 14); 20.672, R = 16.7 (J. Brimacombe,
Cairns, Australia; position end figures 07s.31, 08".6; image posted at
website URL http://www.flickr.com/photos/43846774@N02/8110432939/); 20.679,
16.7 (Brimacombe; infrared filter, bandpass > 700 nm; position end figures
07s.18, 08".0; image posted at the following website URL:
http://www.flickr.com/photos/43846774@N02/8109994621/).

     M. Childress, R. Scalzo, F. Yuan, B. Tucker, and B. Schmidt, Australian
National University (ANU), report that they obtained a 20-min spectrogram of
PSN J06200624-6457085 = SN 2012gp on Nov. 19.73 UT with the Wide Field
Spectrograph (WiFeS; Dopita et al. 2007, Ap. Space Sci. 310, 255; note
correction to volume number given in CBET 3277) on the ANU 2.3-m telescope at
Siding Spring Observatory using the B3000/R3000 gratings (range 350-980 nm at
0.1-nm resolution.  The spectrum was compared to supernova spectral templates
using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024), and the best match was
to the spectrum of the normal type-Ia supernova 2001N at +30 days and
redshift z = 0.054 +/- 0.005, consistent with the redshift of its apparent
host galaxy, PGC 75651 (z = 0.0526, from Smith et al. 2004, A.J. 128, 1558;
via NED).  Given this redshift, the Si 635.5-nm line is identifiable at rest
wavelength 619.0 nm, as well as Fe blends at 517.0 and 435.0 nm rest
wavelengths.


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

                         (C) Copyright 2012 CBAT
2012 November 24                 (CBET 3306)              Daniel W. E. Green