[IAUC] CBET 3148: 20120619 : SUPERNOVA 2012cw IN NGC 3166 = PSN J10134795+0326026

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                                                  Electronic Telegram No. 3148
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 2012cw IN NGC 3166 = PSN J10134795+0326026
     Koichi Itagaki, Yamagata, Japan, reports his discovery of an apparent
supernova (mag 16.5) on an unfiltered CCD image (limiting magnitude 19.5)
taken on June 14.484 UT with a 0.60-m f/5.7 reflector; the new object is
located at R.A. = 10h13m47s.95, Decl. = +3d26'02".6 (equinox 2000.0; UCAC3
reference stars), which is 34" east and 33" north of the nucleus of the galaxy
NGC 3166 (whose measured position end figures are 45s.68, 25'29".4).
Itagaki has posted his discovery image at URL http://www.k-itagaki.jp/3166.jpg.
The variable was designated PSN J10134795+0326026 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012cw based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2012cw:  June 14.516, 16.3 (T. Noguchi, Chiba-ken, Japan; position end figures
47s.91, 02".4; UCAC3 reference stars; 0.23-m f/6.3 Schmidt-Cassegrain reflector
+ BITRAN BT-11E camera; limiting mag 17.5; communicated by S. Nakano; image
posted at website URL http://park8.wakwak.com/~ngc/images/PSNinNGC3166.jpg);
15.162, 16.3 (T. Yusa, Osaki, Japan; remotely using a 0.25-m f/3.4 hyperbolic
astrograph + SBIG ST-10XME camera of the iTelescope network at the RAS
Observatory near Mayhill, NM, U.S.A.; position end figures 47s.97, 02".1;
reference stars from USNO-B1.0 catalogue; limiting mag 19.3; image posted at
URL http://space.geocities.jp/yusastar77/supernova/PSNinNGC3166_120615.htm);
15.415, 16.0 (Joseph Brimacombe, Cairns, Australia; red filter implied;
position end figures; 47s.96, 02".3; image posted at the following website
URL:  http://www.flickr.com/photos/43846774@N02/7383312592/).

     X.-F. Wang and Q. Liu, Tsinghua Center for Astrophysics, Tsinghua
University; J.-J. Zhang, Yunnan Astronomical Observatory of China (YNAO);
and T.-M. Zhang, National Astronomical Observatory of China, report on an
optical spectrogram (range 340-920 nm) of PSN J10134795+0326026 = SN 2012cw
that was obtained on June 18.5 UT with the 2.4-m telescope (+ YFOSC) at the
LiJiang Gaomeigu Station of the YNAO.  The spectrum is consistent with a
type-Ic supernova around maximum light.  Cross-correlation with a library of
supernova spectra using the "Supernova Identification" code (SNID; Blondin
and Tonry 2007, Ap.J. 666, 1024) shows that 2012cw matches the normal type-Ic
supernova 2004aw at +2 days.  Adopting a recession velocity 1345 km/s for the
host galaxy, NGC 3166 (after de Vaucouleurs et al. 1991, RC3.9C; via the NED),
they measure the velocity of the Si II 635.5-nm absorption feature to be about
11400 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 June 19                     (CBET 3148)              Daniel W. E. Green