[IAUC] CBET 3207: 20120824 : SUPERNOVA 2012eg IN NGC 1213 = PSN J03091697+3838207

Vie Ago 24 06:33:53 ART 2012

                                                  Electronic Telegram No. 3207
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 2012eg IN NGC 1213 = PSN J03091697+3838207
     T. Boles, Coddenham, England, reports the discovery of an apparent
supernova (mag 17.7) on unfiltered CCD images taken on Aug 18.1086 and
19.1038 UT with a 0.35-m reflector.  The new object is located at R.A. =
3h09m16s.97, Decl. = +38o38'20".7 (equinox 2000.0), which is approximately
4".1 west and 37".5 south of the center of NGC 1213.  Nothing is present at
this position on Boles' images from 2011 Oct. 20 and 2012 Jan. 22 (limiting
mag 19.5) or on Digitized Sky Survey Ppates from 1989 Sept. 30 (limiting
red mag 20.5) and 1989 Sept. 5 (limiting blue mag 21.0).  The object was
designated PSN J03091697+3838207 when it was posted at the Central Bureau's
TOCP webpage and is here designated SN 2012eg based on the spectroscopic
confirmation reported below.  Additional CCD magnitudes for SN 2012eg:
2012 Aug. 20.468, 17.8 (Joseph Brimacombe, Cairns, Australia; remotely
using a 51-cm RCOS telescope + STL11K camera + luminance filter at New
Mexico Skies Observatory near Mayhill, NM, USA; position end figures 16s.97,
21".0; image posted at website URL
http://www.flickr.com/photos/43846774@N02/7827415676/); 22.022, 17.3
(Xavier Bros, Ager, Spain; 35-cm f/4.6 telescope; position end figures
16s.93, 21".2; UCAC2 reference stars; Image posted at website URL
http://www.anysllum.com/SN_NGC1213.jpg).

     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 PSN J03091697+3838207
= SN 2012eg with the Nordic Optical Telescope (+ ALFOSC; range 350-900 nm,
resolution 0.8 nm) on Aug. 21.14  UT.  The fully reduced spectrum of
SN 2012eg shows this to be a normal type-IIP supernova a week or some weeks
past maximum.

     M. Fraser, D. Wright, and R. Kotak, Queens University, Belfast;
and T. Boles, Coddenham, report that a spectrogram (range 330-975 nm;
resolution about 1000) of SN 2012eg = PSN J03091697+3838207 was obtained
by I. Arcavi on Aug. 22.4 UT with the 4.2-m William Herschel Telescope
(+ ISIS).  Cross-correlation with a library of supernova spectra via the
"Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J.
666, 1024) shows that SN 2012eg is a type-IIP supernova similar to SN 2005cs
about one month after explosion.  The velocity of the P-Cyg absorption
minimum in H_alpha is about 4500 km/s, which is significantly lower than
that of a normal type-IIP event at this epoch.  In addition, the absolute
magnitude of SN 2012eg at the distance of NGC 1213 is -15.5, similar to that
of other sub-luminous type-IIP supernovae.


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 3207)              Michael Rudenko