[IAUC] CBET 3167: 20120707 : SUPERNOVA 2012dj IN NGC 7531 = PSN J23144798-4336223

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                                                  Electronic Telegram No. 3167
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 2012dj IN NGC 7531 = PSN J23144798-4336223
     Greg Bock, Windaroo, Queensland, Australia, reports the discovery of an
apparent supernova (mag 15.3) by Stuart Parker (Oxford, Canterbury, New
Zealand) on a 30-s unfiltered CCD image taken by Parker with a 35-cm Celestron
C14 reflector (+ ST10 camera) on July 1.66 UT.  Bock measures the position of
the new object to be R.A. = 23h14m47s.98, Decl. = -43d36'22".3 (equinox
2000.0; reference stars from USNO-B and UCAC3 catalogues), which was noted to
be 5' [sic] west and 23' [sic] south of the nucleus of the galaxy NGC 7531
(Bock surely meant the offset numbers to be in arcsec instead of arcmin).
Nothing is visible at this position on an image taken by Stuart on June 26
(limiting red mag > 18.0) or on Digitized Sky Survey red and infrared images
(limiting red mag > 19).  The variable was designated PSN J23144798-4336223
when it was posted at the Central Bureau's TOCP webpage and is here designated
SN 2012dj based on the spectroscopic confirmation reported below.  A. Klotz
reports magnitude R = 14.5 +/- 0.1 on July 7.33 from an image obtained with
the TAROT telescope at La Sille, Chile.

     J. T. Parrent and D. A. Howell report that an optical spectrum (range
350-970 nm) of PSN J23144798-4336223 = 2012dj was obtained on July 6 UT with
the Gemini-Multi-Object-Spectrograph (GMOS) on the 8-m Gemini South telescope.
Cross comparisons with a library of supernovae spectra via "Superfit" (Howell
et al. 2005, Ap.J. 634, 1190) suggest that 2012dj is a type-Ib/c supernova
near maximum light.  Correcting for a host-galaxy recession velocity of 1597
km/s for NGC 7531 (HIPASS, via NED), the He I 587.6-nm absorption feature is
estimated to be blue-shifted by 6400 km/s.


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                         (C) Copyright 2012 CBAT
2012 July 7                      (CBET 3167)              Daniel W. E. Green