Electronic Telegram No. 2706
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2010ma = GRB 101219B
     M. Sparre, J. Fynbo, A. de Ugarte Postigo, and D. Malesani, Dark
Cosmology Centre; and J. Sollerman, Oskar Klein Centre, on behalf of the
X-shooter GTO GRB collaboration, report that medium-dispersion spectra (range
300-2200 nm, resolution 0.1 nm) of the afterglow associated with GRB 101219B
(cf. GCN 11473, accessible at URL http://gcn.gsfc.nasa.gov/gcn3/11473.gcn3;
position given as R.A. = 0h48m55s.35, Decl. = -34d33'59".5, equinox 2000.0)
were obtained with the Very Large Telescope (+ X-shooter) at the European
Southern Observatory, Paranal, on three dates (at mean times 2010 Dec. 20.17,
2011 Jan. 5.09, and Jan. 25.55 UT, corresponding to 11.6 hr, 16.4 days, and
36.9 days after the burst, respectively).  The exposure times were 80, 120,
and 120 min, respectively.  The first-epoch spectrum, where the afterglow is
detected over the full spectral range, displays a power-law continuum typical
for GRB afterglows (cf. GCN 11579).  The fully reduced second-epoch spectrum,
however, is best matched with a fading afterglow dominating the bluest
regions, whereas the 500- to 900-nm region is well matched with the spectrum
of the broad-lined type-Ic supernova 1998bw (Patat et al. 2001, Ap.J. 555,
900) taken eight days after outburst.  The third-epoch spectrum contains
less signal but is still fully consistent with a supernova spectrum, given
the redshift of z = 0.55 (GCN 11579).  The designation 2010ma is assigned
to this supernova.


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                         (C) Copyright 2011 CBAT
2011 April 21                    (CBET 2706)              Daniel W. E. Green