[IAUC] CBET 3422: 20130220 : SUPERNOVA 2013ab IN NGC 5669 = PSN J14324449+0953123

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 3422
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 2013ab IN NGC 5669 = PSN J14324449+0953123
     [Editor's note:  this text replaces that on CBET 3421.]
     Further to CBET 3302, P. Blanchard, W. Zheng, S. B. Cenko, W. Li, and
A. V. Filippenko report the LOSS discovery of an apparent supernova on
unfiltered KAIT images:

 SN       2013 UT        R.A. (2000.0) Decl.      Mag.      Offset
 2013ab   Feb. 17.54   14 32 44.49  + 9 53 12.3   17.6    7".5 E, 18".1 S

The variable was designated PSN J14324449+0953123 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013ab based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2013ab:  Feb. 15.53 UT, [18.4 (KAIT); 18.443, 15.2 (J. Brimacombe, Cairns,
Australia; remotely with a 51-cm RCOS telescope + luminance filter located at
the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end
figures 44s.45, 12".2); 19.030, V = 15.2 (M. Martignoni, Magnago, Italy;
0.25-m reflector; position end figures 44s.44, 12".1).  Brimacombe's image is
posted at website URL http://www.flickr.com/photos/43846774@N02/8487144228/.

     S. B. Cenko, W. Zheng, and A. V. Filippenko, University of California,
Berkeley; and A. Cucchiara, University of California Observatories, Lick
Observatory, report that they obtained a CCD spectrogram (range 340-800 nm) of
PSN J14324449+0953123 = SN 2013ab on Feb. 18.38 UT with the Kast double
spectrograph on the Shane 3-m telescope at Lick Observatory.  The spectrum is
dominated by a largely featureless blue continuum, with superimposed narrow
emission lines from the underlying host galaxy, establishing a redshift of
0.0046 (HIPASS survey, via NED).  These properties are suggestive of a very
young type-II supernova.  Further observations are encouraged to verify this
classification.

     S. Valenti, Las Cumbres Observatory Global Telescope (LCOGT) and
University of California at Santa Barbara (UCSB); D. Sand, Texas Tech
University; J. T. Parrent, LCOGT and Dartmouth College; and M. L. Graham and
D. A. Howell, LCOGT and UCSB, report that a spectrogram (range 350-1000 nm)
of PSN J14324449+0953123 = SN 2013ab, obtained robotically on Feb. 18.70 UT
with the FLOYDS (FTS) spectrograph on the "Faulkes Telescope South" at Siding
Spring, shows it to be a young type-II supernova.  The spectrum shows a
blue continuum with a broad feature at about 460.0 nm.  The Balmer lines are
not visible.  Comparisons with a library of supernova spectra using the
"GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383) yields the best match
with SN 2000ck (cf. IAUC 7431).


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

                         (C) Copyright 2013 CBAT
2013 February 20                 (CBET 3422)              Daniel W. E. Green