[IAUC] CBET 2970: 20120107 : SUPERNOVA 2011jt IN PGC 53208 = PSN J14532301+0257431

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 2970
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 2011jt IN PGC 53208 = PSN J14532301+0257431
     A. J. Drake, S. G. Djorgovski, M. J. Graham, A. Mahabal, and R. Williams,
California Institute of Technology; J. L. Prieto, Princeton University; M.
Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M.
Larson, Lunar and Planetary Laboratory, University of Arizona; and E.
Christensen, Gemini Observatory, report the discovery of an apparent supernova
in unfiltered Catalina Sky Survey (CSS) images:

 SN       2011 UT       R.A. (2000.0) Decl.      Mag.      Offset
 2011jt   Dec. 31.54   14 53 23.01  + 2 57 43.1   17.0    5".8 W, 16".4 S

The variable was designated PSN J14532301+0257431 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2011jt based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2011jt:  2011 June 23.25 UT, [20.3 (CSS); 2012 Jan. 1.526, 16.5 (Joseph
Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K
camera + luminance filter at the New Mexico Skies Observatory near Mayhill,
NM, U.S.A.; position end figures 23s.02, 42".9; image posted at website URL
http://www.flickr.com/photos/43846774@N02/6618245617/).

     J. M. Silverman and A. V. Filippenko, University of California, Berkeley,
report that inspection of a CCD spectrum (range 340-1000 nm), obtained on Jan.
3 UT with the Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory,
shows that PSN J14532301+0257431 = SN 2011jt is a type-Ia supernova.  After
removal of the host-galaxy recession velocity of 8334 km/s (from the Sloan
Digital Sky Survey Data Release 1), they find the absorption minimum of the
Si II 635.5-nm line to be blueshifted by about 14700 km/s.  Cross-correlation
with a library of supernova spectra using the "SuperNova IDentification" code
(SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that the object is
a normal type-Ia supernova about six days before maximum brightness.

     J.-C. Chen and X.-F. Wang, Tsinghua Center for Astrophysics, Tsinghua
University; X. Zhan, Beijing Planetarium; T.-M. Zhang, National Astronomical
Observatory of China (NAOC), report on an optical spectrogram (range 400-8800
nm) of PSN J14532301+0257431 = SN 2011jt that was obtained on 2012 Jan. 3.9 UT
with the 2.16-m telescope (+ OMR) at Xinglong Station of NAOC.  The spectrum
is consistent with a type-Ia supernova at about one week before maximum.
Cross-correlation with a library of supernova spectra using the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows
that it matches with SN 2002bo at -9 days.  Adopting a recession velocity of
8334 km/s for the host galaxy from the NED, they measure a velocity of the Si
II 635.5-nm absorption feature to be about 15000 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 January 7                   (CBET 2970)              Daniel W. E. Green