[IAUC] CBET 1940: 20090911 : SUPERNOVA 2009iv

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                                                  Electronic Telegram No. 1940
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2009iv
     Editor's note:  this text replaces that on CBET 1939.
     E. Chatzopoulos, University of Texas; J. Vinko, University of Texas;
F. Yuan, University of Michigan; R. Quimby, California Institute of
Technology; D. Chamarro, M. D. Sisson, C. Akerlof, S. B. Pandey, University
of Michigan; and J. C. Wheeler, University of Texas, on behalf of the ROTSE
collaboration, report the discovery of a type-Ia supernova (mag about 17.6)
in unfiltered images taken on Aug. 21.43 UT with the 0.45-m ROTSE-IIIb
telescope at the McDonald Observatory.  The new object was detected again
ten days later at mag about 17.7 in confirmation images taken with the
ROTSE-IIId telescope.  SN 2009iv is located at R.A. = 2h58m14s.19, Decl. =
+5o58'19".3 (equinox 2000.0; uncertainty about 1"), which is consistent with
the core of the apparent host galaxy, 2MASX J02581424+0558189, at a redshift
of z = 0.023 (according to the SIMBAD database).  Two spectra (range 420-1020
nm), obtained on Aug. 29.43 and Sept. 9.72 with the Low Resolution Spectrograph
on the 9.2-m Hobby-Eberly Telescope, show 2009iv to be a type-Ia supernova.
The spectra contain the Si II 635.5-nm line, and also other S II/Mg II/Fe II
features characteristic of type-Ia events, but they are heavily contaminated
by the host galaxy; an E0-galaxy spectrum template was used to remove the
contamination by the host galaxy.  SNID (Blondin and Tonry 2007, Ap.J. 666,
1024) also identified the transient as a type-Ia supernova 28 days after
maximum.  A finding chart for 2009iv can be found at the following website
URL:  http://www.rotse.net/rsvp/j025814.2+055819/j025814.2+055819.jpg.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2009 CBAT
2009 September 11                (CBET 1940)              Daniel W. E. Green