[IAUC] CBET 3206: 20120824 : SUPERNOVA 2012ef = PSN J23501925+1637562

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 3206
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 2012ef = PSN J23501925+1637562
     Vladimir Lipunov, Sternberg Astronomical Institute (SAI), reports the
discovery by P. Podvorotniy of a possible supernova (magnitude 18.1) on
two unfiltered 180-s images obtained with a 0.40-m f/2.5 MASTER-Kislovodsk
robotic telescope (+ 16-megapixel CCD camera) on Aug. 18.02 and 18.03 UT.
The new object is located at R.A. = 23h50m19s.25, Decl. = +16d37'56".2
(equinox 2000.0), which is 7".3 east and 2".4 north of the nucleus of the
presumed host galaxy.  Nothing was visible at this postion on a MASTER-
Kislovodsk image taken on 2010 Dec. 23.66 (limiting magnitude 20.3), or on
nine Digitized Sky Survey plates taken between 1954 Aug. 26 and 1995 Oct. 25
(limiting mag about 22.5; details not specified), or on sixty Palomar/NEAT
unfiltered CCD images from 22 different nights spanning 2000 Aug. 4 - 2005
Aug. 14 (limiting mag about 23 on a sum of 48 of the best NEAT images).
The discovery and reference images are posted at  the following website URL:
http://master.sai.msu.ru/static/OT/235019.25163756.2_1.png.  D. Denisenko
(SAI), and V. Yurkov and E. Sinyakov (Blagoveschensk Educational State
University) report, on behalf of a larger MASTER collaboration, that this
possible supernova was marginally visible on 60-s unfiltered images taken by
an identical MASTER-Amur telescope on 2012 Aug. 9.73 and 9.76.  A comparison
of the Aug. 9 MASTER-Amur and Aug. 18 MASTER-Kislovodsk images is posted at
http://master.sai.msu.ru/static/OT/PSNJ23501925+1637562-Amur120809.jpg.
This object was designated PSN J23501925+1637562 when it was posted at
the Central Bureau's TOCP webpage and is here designated SN 2012ef based on
the spectroscopic report below.

     J. Sollerman, Stockholm University; and M. Stritzinger, Aarhus
University, report (on behalf of the observers A. Hammer Holm, J. Jul
Jensen, A. Paaske Drachmann, M. Juhl Hobert, and J. Fynbo from Copenhagen
University) that they obtained optical spectroscopy of 2012ef with the
Nordic Optical Telescope (+ ALFOSC; range 350-900 nm, resolution 0.8 nm) on
Aug. 21.15  UT.  The fully reduced spectrum indicates that 2012ef is a
normal type-Ia supernova at a redshift of 0.08.  The supernova is about one
week past maximum.


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

                         (C) Copyright 2012 CBAT
2012 August 24                   (CBET 3206)              Michael Rudenko