[IAUC] CBET 1021: 20070804 : SUPERNOVA 2007gi IN NGC 4036

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                                                  Electronic Telegram No. 1021
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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SUPERNOVA 2007gi IN NGC 4036
     A. Harutyunyan, S. Benetti, E. Cappellaro, Istituto Nazionale di
Astrofisica, Osservatorio Astronomico di Padova; F. Patat, European Southern
Observatory; and F. Ghinassi, Telescopio Nazionale Galileo (TNG), report
that a spectrum of 2007gi (cf. CBET 1017), obtained on Aug. 4.90 UT with the
3.5-m TNG (+ DOLORES; range 380-750 nm, resolution 1.8 nm), shows it to be a
type-Ia supernova well before maximum.  The best fit to this spectrum found
by the 'PASSparToo' supernova-spectra comparison tool (Harutyunyan et al.
2005, ASP Conf. Ser. 342, 258) is with the type-Ia supernova 1999dk at 13
days before maximum, though 2007gi shows a higher expansion velocity -- i.e.,
20500 km/s, as measured from the Si II 635-nm feature, and adopting 1445 km/s
for the host-galaxy recession velocity (Falco et al. 1999, PASP 111, 438).
Also, the S II absortions, measured at 532 and 559 nm in the galaxy rest
frame, are stronger.


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                         (C) Copyright 2007 CBAT
2007 August 4                    (CBET 1021)              Daniel W. E. Green