Central Bureau for Astronomical Telegrams
IAUC 8099: 2003cg; C/2002 V6, C/2002 V7
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Circular No. 8099
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2003cg IN NGC 3169
R. Kotak and W. P. S. Meikle, Imperial College, London; and F.
Patat, European Southern Observatory, on behalf of the European
Supernova Collaboration, report that a spectrum (range 427-686 nm)
of SN 2003cg (cf. IAUC 8097), obtained at the William Herschel
Telescope (+ ISIS) by G. Nelemans on Mar. 22.9 UT, shows it to be a
highly-reddened 'normal' type-Ia supernova, a few days before
maximum (compared to SN 1994D; Patat et al. 1996, MNRAS 278, 111),
with a total extinction of A_v about 2.5 magnitudes. Very strong,
multicomponent Na I D interstellar absorption lines are present in
the rest frame of the host galaxy.
Further to IAUC 8091, T. Matheson et al. write that a spectrum
of SN 2003cg, obtained by L. Macri on Mar. 25.23 UT, shows it to be
a highly reddened, possibly subluminous type-Ia supernova near
maximum. Adopting the NED recession velocity (1238 km/s) for the
host galaxy, the supernova expansion velocity is 11500 km/s for Si
II (rest 635.5 nm). Several titanium absorption features appear
stronger than usual, with the entire spectrum resembling that of
the subluminous SN 1999by just before maximum (see Garnavich et al.
2003, Ap.J., in press; http://xxx.lanl.gov/abs/astro-ph/?0105490).
The spectrum shows a strong narrow Na I D absorption at the
velocity of the host galaxy with an equivalent width of 0.55 nm.
There are several other narrow absorptions in the spectrum that
appear to coincide with known diffuse interstellar bands (e.g.,
544.9, 578.0, 628.3 nm, etc.) at the host velocity. In addition,
the overall shape of the spectrum declines toward the blue,
implying that the supernova is heavily extinguished by dust. The
Schlegel et al. (1998, Ap.J. 500, 525) dust maps indicate a low
value for Galactic reddening of E(B-V) = 0.031.
Corrigenda. On IAUC 8097, lines 2, 7, and 16, FOR Itagati
READ Itagaki
COMETS C/2002 V6 AND C/2002 V7 (SOHO)
Further to IAUC 8073, D. Hammer reports measurements for two
additional Kreutz sungrazing comets found on SOHO C2 website images
by K. Cernis (C/2002 V6) and R. Matson (C/2002 V7); C/2002 V6 was
also visible with the C3 coronagraph. The reduced astrometry and
orbital elements by B. G. Marsden appear on MPEC 2003-F14.
Comet 2002 UT R.A. (2000) Decl.
C/2002 V6 Nov. 13.179 15 08.2 -21 00
C/2002 V7 15.850 15 21.5 -20 07
(C) Copyright 2003 CBAT
2003 March 25 (8099) Daniel W. E. Green
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