[IAUC] CBET 2869: 20111022 : SUPERNOVA 2011gw IN IC 2200 = PSN J07281702-6221189

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 2869
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 en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2011gw IN IC 2200 = PSN J07281702-6221189
     G. Pignata and M. Cifuentes, Universidad Andres Bello; J. Maza, M. Hamuy,
R. Antezana, L. Gonzalez, R. Cartier, F. Forster, S. Silva, F. Carrasco, P.
Sanchez, C. Hervias, D. Iturra, and R. Ramirez, Universidad de Chile; C.
Farias, Pontificia Universidad Catolica de Chile; B. Conuel, Wesleyan
University; G. Folatelli, IPMU, University of Tokyo; and D. Reichart, K.
Ivarsen, J. Haislip, A. Crain, D. Foster, M. Nysewander, and A. LaCluyze,
University of North Carolina at Chapel Hill, on behalf of the CHASE project
(which is part of the Millennium Center for Supernova Science collaboration),
report the discovery of an apparent Supernova (mag approximately 17.4) on an
unfiltered image taken on Sept. 15.36 UT with the 0.41-m 'PROMPT 3' telescope
located at Cerro Tololo.  The new object, which is also present in an image
taken on Sept. 13.38 at mag approximately 17.2, is located at R.A. =
7h28m17s.02 +/- 0".2, Decl. = -62o21'18".9 +/- 0".2 (equinox 2000.0), which
is about 3".9 west and 8".0 south of center of the galaxy IC 2200.  Nothing
is visible at this position on archival images taken on 2010 Dec. 22.16
(limiting mag 18.0) and 2010 Oct. 27.25 (limiting mag 17.5).  The variable
was designated PSN J07281702-6221189 when it was posted on the Central
Bureau's TOCP webpage and is here designated SN 2011gw based on the
spectroscopic confirmation reported below.

     P. Ochner, S. Valenti, S. Benetti, A. Pastorello, and L. Tomasella,
Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Padova;
and F. Bufano, INAF, Osservatorio Astronomico di Catania, on behalf of a
larger collaboration, report that a spectrum of PSN J07281702-6221189 = SN
2011gw, obtained on Oct. 20.33 UT with the New Technology Telescope (+ EFOSC2;
range 360-930 nm; resolution 1.8 nm), shows it to be a type-Ib/c supernova.
The best fits to this spectrum found by GELATO (Harutyunyan et al. 2008, A.Ap.
488, 383; publicly available at https://gelato.tng.iac.es) are with spectra of
type-Ib/c supernovae at about two months post-maximum, after adopting a
recessional velocity of 3248 km/s for IC 2200 (Sekiguchi and Wolstencroft
1992, MNRAS 255, 581; via NED).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 October 22                  (CBET 2869)              Daniel W. E. Green