[IAUC] CBET 3267: 20121024 : SUPERNOVA 2012fk NEAR PGC 9572 AND PGC 9568 = PSN J02305204+2228459

Mar Oct 23 20:42:45 ART 2012

                                                  Electronic Telegram No. 3267
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 2012fk NEAR PGC 9572 AND PGC 9568 = PSN J02305204+2228459
     V. Lipunov (Sternberg Astronomical Institute at Lomonosov, Moscow State
University) reports the discovery by S. Shurpakov of an apparent supernova
(magnitude 16.7) on unfiltered 60-s images obtained with the MASTER-Amur
robotic telescope (0.40-m f/2.5) on Oct. 20.711 and 20.742 UT.  The new object
is located at R.A. = 2h30m52s.04, Decl. = +22d28'45".9 (equinox 2000.0), which
is 19".7 east and 33".2 north of the nucleus of the core of the likely host
galaxy PGC 9572 (though they note that there are two smaller galaxies that are
closer to the new object than is PGC 9572, with their regions overlapping).
Nothing is visible at the position of the new object on a color-combined Sloan
Digital Sky Survey image from 2009 Jan. 11 (limiting magnitude about 23) or
on a MASTER-Amur image from 2011 Sept. 6.723 (limiting mag 18.8).  The
discovery and reference images are posted at the following website URL:
http://master.sai.msu.ru/static/OT/023052.04222845.9.png.  The variable was
designated PSN J02305204+2228459 when it was posted at the Central Bureau's
TOCP webpage and is here designated SN 2012fk based on the spectroscopic
confirmation reported below.  Additional CCD magnitudes for 2012fk:  Oct.
23.119, 17.3 (Federica Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8
reflector; position end figures 52s.09, 46".3; reference stars from CMC-14
catalogue); image posted at http://www.astrogeo.va.it/pub/TOCP/PSN_P9572.jpg);
Oct. 23.198, 17.6 (Joseph Brimacombe, Cairns, Australia; luminance filter
position end figures 52s.01, 47".3; image posted at the following website URL:
http://www.flickr.com/photos/43846774@N02/8117697662/); Oct. 23.199, 17.2
(R. A. Koff, Bennett, CO, USA; Meade 0.25-m f/10 reflector + Apogee U-47
camera; some high clouds; limiting magnitude 19.5; position end figures
52s.09, 46".0; UCAC3 reference stars; image posted at the following URL:
http://antelopehillsobservatory.org/SNpictures/PSNJ02305204+2228459final.jpg).

     L. Tomasella, S. Benetti, E. Cappellaro, A. Pastorello, and M. Turatto,
Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report
that a spectrogram of PSN J02305204+2228459 = 2012fk, obtained on Oct. 22.92
UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC range 350-820 nm,
resolution 1.3 nm), indicates that it is a type-Ia supernova.  Cross-
correlation with a library of supernova spectra via the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) and via
GELATO (Harutyuyan et al. 2008, A.Ap. 488, 383) shows that 2012fk has a
redshift of about 0.035 and is similar to several normal type-Ia supernovae
at maximum light.  The expansion velocity deduced from the Si II 635.5-nm
absorption is then 11600 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 October 24                  (CBET 3267)              Daniel W. E. Green