Electronic Telegram No. 393
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html


SUPERNOVA 2006X IN NGC 4321
     R. Quimby, University of Texas; P. Brown, Pennsylvania State
University; and C. Gerardy, Imperial College, report that a
spectrogram (range 420-890 nm) of 2006X (cf. IAUC 8667), obtained
on Feb. 8.35 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario
Low-Resolution Spectrograph) by S. C. Odewahn and S. Rostopchin
under poor conditions, shows it to be an early type-Ia supernova.
The spectra are similar to those of SN 2002bo at 1-2 weeks before
maximum light (Benetti et al. 2004, MNRAS 348, 261), but with a
redder continuum.  Adopting the recession velocity of 1571 km/s
for the host (Rand 1995, A.J. 109, 2444, via NED), the velocity of
the Si II 635.5-nm minimum is 20700 km/s.
     R. Quimby and M. Sellers, University of Texas, add that SN
2006X appeared at mag about 15.3 on unfiltered CCD images taken on
Feb. 7.31 UT with the 0.45-m ROTSE-IIIb telescope at the McDonald
Observatory; the position for 2006X was measured as R.A. =
12h22m53s.88, Decl. = +15o48'31".9 (equinox 2000.0; uncertainty +/-
0".6).  SN 2006X was not detected in ROTSE-IIIb images taken Feb.
1.32 (limiting mag about 17.9) or in a co-addition of images taken
between 2004 Dec. 11 and 2005 June 8 (limiting mag about 19.0).


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2006 CBAT
2006 February 8                  (CBET 393)               Daniel W. E. Green