[IAUC] CBET 3155: 20120627 : SUPERNOVA 2012db IN ESO 139-G28 = PSN J17484870-6042193

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 3155
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 2012db IN ESO 139-G28 = PSN J17484870-6042193
     A. Klotz, on behalf of the TAROT collaboration, reports the discovery of
an apparent supernova (magnitude R = 14.6 +/- 0.1) on June 24.27 using public
images of the 0.25-m TAROT robotic telescope at La Silla, Chile.  The new
object is located at R.A. = 17h48m48s.70, Decl. = -60o42'19".3 (equinox
2000.0), which is 17" west and 4" north of the nucleus of ESO 139-G28.  The
variable was designated PSN J17484870-6042193 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2012db based on the
spectroscopic confirmation reported below.  Additional R-band CCD magnitudes
for 2012db:  June 6.302, [17.9 (Klotz, via TAROT); 21.269, 14.7 (Klotz, via
TAROT; pre-discovery); 25.4, 15.5 (Ernesto Guido, Nick Howes, and Giovanni
Sostero; remotely with the 2.0-m f/10 Ritchey-Chretien "Faulkes Telescope
South" at Siding Spring; Bessell R filter; position end figures 48s.63,
19".0; UCAC-3 catalogue reference stars; an animation showing a comparison
between their confirmation image and the archival red Digitized Sky Survey
plate from 1990 is posted at website URL http://bit.ly/KneUqF, with an
annotated confirmation image posted at http://bit.ly/MvHRUT).

     E. Y. Hsiao, M. M. Phillips, N. Morrell, and C. Contreras, Las Campanas
Observatory; J. Prieto, Princeton University; and G. H. Marion, Harvard-
Smithsonian Center for Astrophysics, report that a near-infrared spectrum
(range 830-2500 nm) of PSN J17484870-6042193 = SN 2012db was obtained on June
26.7 UT with the Folded-port Infrared Echellette (FIRE) spectrograph on the
6.5-m Magellan Baade Telescope.  The spectrum shows that 2012db is a type-Ia
supernova a few days before maximum light.  The near-infrared spectrum is
similar to that of SN 2002cr at five days before maximum (Marion et al. 2009,
A.J. 138, 727).  The velocity of the Mg II 1092.7-nm absorption feature is
measured to be approximately 13000 km/s, using an estimated redshift for the
presumed host galaxy (ESO 139-G28) of z = 0.019 (de Vaucouleurs et al. 1991,
RC3.9C; via NED).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2012 CBAT
2012 June 27                     (CBET 3155)              Daniel W. E. Green