Electronic Telegram No. 839
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 2007S IN UGC 5378
     S. Blondin, M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian
Center for Astrophysics, report that a spectrum (range 350-740 nm) of SN
2007S (cf. CBET 825), obtained on Feb. 8.35 UT by P. Berlind with the F. L.
Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a type-Ia
supernova around maximum light, confirming the classification given on CBET
829 by Jones et al.  Cross-correlation with a library of type-Ia supernova
spectra indicates that 2007S is most similar to the 1991T-like supernova
1998es (cf. IAUC 7054) at 2 days before maximum light.  Adopting a recession
velocity of 4174 km/s for the host galaxy (from "The Updated Zwicky Catalog",
http://tdc-www.harvard.edu/uzc/), the maximum absorption in the Si II line
(rest 635.5 nm) is blueshifted by roughly 10500 km/s.  Also, interstellar Na
I D absorption at the redshift of the host galaxy is visible in the spectrum
with an equivalent width of 0.3 nm, which suggests some reddening.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 February 8                  (CBET 839)               Daniel W. E. Green