24 March 2010
IAU Electronic Telegram No.2227
--------------------------------------------------------------------------------
SUPERNOVA 2010bh = GRB 100316D
--------------------------------------------------------------------------------
F. Bufano, S. Benetti, and E. Cappellaro, Istituto Nazionale di
Astrofisica (INAF), Osservatorio Astronomico di Padova (OAP); S. Covino, INAF,
Osservatorio Astronomico di Brera (OAB); S. Vergani, Galaxie, Etoile,
Physique, Instrumentation (GEPI), Observatoire de Paris, and Astroparticule
et Cosmologie (APC), Universite Paris 7; P. Goldoni, APC, Universite Paris 7,
and Service d'Astrophysique, Commissariat a l'Energie Atomique (CEA); M.
Della Valle, INAF, Osservatorio di Capodimonte; E. Pian, INAF, Osservatorio
Astronomico di Trieste; S. Campana and G. Tagliaferri, INAF, OAB; D. Malesani
and J. Fynbo, Dark Cosmology Centre, University of Copenhagen; M. Turatto,
INAF, Osservatorio Astronomico di Catania; F. Patat, European Southern
Observatory (ESO); and P. Mazzali, INAF, OAP, on behalf of a larger
collaboration, report that a high-dispersion optical spectrum (range 350-900
nm, resolution 0.02 nm) of the afterglow associated with GRB 100316D (cf.
GCN 10496; visible at http://gcn.gsfc.nasa.gov/gcn3/10496.gcn3) was obtained
with the Very Large Telescope (+ XShooter) at ESO/Paranal on Mar. 23.04 UT.
The spectrum of the source located at R.A. = 7h10m31s.8 and Decl. =
-56o15'20".2 (equinox 2000.0; as measured on the XShooter acquisition image)
shows very broad bumps with peaks measured at about 430 and 670 nm,
reminiscent of an emerging broadline type-Ic supernova (in agreement with
Chornock et al., GCN 10541). Indeed, above 600 nm, the spectrum of this
source shows some similarities with that of SN 1998bw (Patat et al. 2001,
Ap.J. 555, 900) taken seven days after outburst. There are, however, major
differences with the spectrum of this transient, showing a significant flux
deficiency in the range 450-550 nm, in comparison with SN 1998bw. The
designation 2010bh is assigned to this supernova.
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
2010 March 24 (CBET 2227) Daniel W. E. Green