[IAUC] CBET 2814: 20110911 : SUPERNOVA 2011fn NEAR NGC 2305 = PSN J06483496-6415545
quai en eps.harvard.edu
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Dom Sep 11 14:10:23 ART 2011
Electronic Telegram No. 2814
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 2011fn NEAR NGC 2305 = PSN J06483496-6415545
Greg Bock, Backyard Observatory Supernova Search (BOSS), Windaroo,
Queensland, Australia, reports the discovery of a possible supernova by Stuart
Parker, Oxford, Canterbury, New Zealand, as part of the BOSS program on a 30-s
unfiltered CCD image taken on June 29.281 UT with a 35-cm Celestron C14 f/6.3
reflector (+ ST10 CCD camera). Colin Drescher, Calamvale, Queensland,
Australia, measures the magnitude of the variable to be 17.9 and its position
as R.A. = 6h48m34s.96, Decl. = -64d15'54".5 (equinox 2000.0), which is 15"
west and 29" north of the center of NGC 2305; nothing is visible at this
position on Digitized Sky Survey red and infrared images (limiting red mag >
19). The new object was designated PSN J06483496-6415545 when it was posted
on the Central Bureau's TOCP webpage and is here designated SN 2011fn based
on the spectroscopic report below.
N. Morrell, Las Campanas Observatory, obtained a rather noisy spectrum
of PSN J06483496-6415545 = SN 2011fn with the Magellan II telescope (+ LDSS3)
on the night of July 28-29. The data show that 2011fn is a supernova, but she
was unable to get a decent fit with the SNID software using the redshift of
NGC 2305; if one allows a redshift of 0.07, as suggested by SNID, one can
find some resasonable matches, but it is difficult to decide between an
'oldish' type-Ia event (say, 1 month past maximum) or a somewhat-younger,
broad-lined type-Ic event (about 20 days past maximum), in which case, the
discovery would have been well before maximum light. Morrell also notes
that, much closer to the supernova position than the NGC 2305 nucleus, there
is a 2MASS source (2MASXi J0648305-641559) that might be the host galaxy.
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2011 CBAT
2011 September 11 (CBET 2814) Daniel W. E. Green
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