[IAUC] CBET 1638: 20081229 : SUPERNOVA 2008in IN M61

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                                                  Electronic Telegram No. 1638
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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SUPERNOVA 2008in IN M61
     S. Chakraborti, Tata Institute of Fundamental Research, Mumbai; T.
Prabhu, Indian Institute of Astrophysics, Bangalore; G. C. Anupama, Indian
Institute of Astrophysics, Bangalore; A. Kaur, Indian Institute of
Astrophysics, Bangalore; G. Uday Kumar, Indian Institute of Astrophysics,
Bangalore; and A. Ray, Tata Institute of Fundamental Research, Mumbai,
report that 2008in (cf. CBET 1636) is a type-IIP supernova.  Medium-resolution
slit spectroscopy (range 400-700 nm; median filtering width 3.0 nm) with the
Himalayan Chandra Telescope at the Indian Astronomical Observatory (operated
by the Indian Institute of Astrophysics) obtained on Dec. 29.00 UT reveals
broad H_alpha emission from the location of the supernova; with the help of
the SNID code (Blondin and Tonry 2007, Ap.J. 666, 1024), the spectrum of
2008in is found to be most similar to that of SN 2005cs at age 1.0 days past
maximum (age from explosion 7.0 days).  The spectrum also similar to that of
SN 1999em at 1.6 days before maximum (age from explosion 8.3 days).
     R. J. Foley, Harvard-Smithsonian Center for Astrophysics, reports that
a CCD spectrum (range 305-1000 nm), obtained on Dec. 29 UT with the 6.5-m
Magellan Clay telescope (+ MagE), shows that 2008in is of type II.  The
spectrum shows the Balmer series, as well as a blue continuum, indicating that
the supernova is relatively young.  Removing the host-galaxy recession
velocity of 1600 km/s (as found from narrow emission lines), the minimum of
the H_alpha P-Cyg absorption is blueshifted by 9600 km/s.
     M. Stritzinger, Las Campanas Observatory (LCO), on behalf of the
Carnegie Supernova Project, reports that a spectrum (range 380-920 nm) of
2008in, obtained on Dec. 29.2 UT with the du Pont telecope (+ WFCCD) at LCO,
shows it to be a type-II supernova.  Adopting a host-galaxy recession
velocity of 1566 km/s (Binggeli et al. 1985, A.J. 90, 1681) for the host
galaxy, H_alpha and H_beta are measured to be blue-shifted by roughly 9000
km/s.  Using of the "SuperNova IDentification" program (Blondin and Tonry
2007, Ap.J. 666, 1024), he finds 2008in to be very similar to SN 1999em and
SN 2004et between one and two weeks past explosion.
     Additional CCD magnitudes for 2008in, unfiltered unless otherwise
noted:  Dec. 27.674 UT, I_c = 13.66 (S. Kiyota, Tsukuba, Japan, 20-cm
Schmidt-Cassegrain telescope); Dec. 28.223, 14.9 (E. Cozzi, Mozzate, Italy;
R.A. = 12h22m01s.74 +/- 0".4, Decl. = +4o28'48".7 +/- 0".4, equinox 2000.0;
0.36-m f/7.6 Schmidt-Cassegrain reflector); 28.458, R = V = 14.3 (W. Wells,
Oklahoma City; revision to his magnitudes on CBET 1636); Dec. 29.05, 15.1 (D.
Denisenko, S. Korotkiy, and T. Kryachko, Moscow; position end figures 01s.75,
48".1, uncertainty 0".2; 80-mm f/7.5 refractor);


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                         (C) Copyright 2008 CBAT
2008 December 29                 (CBET 1638)              Daniel W. E. Green