[IAUC] CBET 2655: 20110214 : SUPERNOVA 2011ac IN UGC 4552 = PSN J08432216+1043476
quai en eps.harvard.edu
quai en eps.harvard.edu
Mie Sep 14 16:19:05 ART 2011
Electronic Telegram No. 2655
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 2011ac IN UGC 4552 = PSN J08432216+1043476
Further to CBET 2651, P. Blanchard, M. Mason, S. B. Cenko, W. Li, and A.
V. Filippenko report the LOSS discovery of an apparent supernova on unfiltered
KAIT images:
SN 2011 UT R.A. (2000.0) Decl. Mag. Offset
2011ac Feb. 11.29 8 43 22.16 +10 43 47.6 17.7 11".2 E, 13".9 N
This object was given the provisional designation PSN J08432216+1043476 when
posted on the Central Bureau's TOCP webpage. Additional (presumed unfiltered
CCD) magnitudes for 2011ac: Feb. 2.31 UT, [19.2 (KAIT); 12.118, 18.1 (R. A.
Koff, Bennett, CO, U.S.A.; position end figures 22s.12, 48".1); 12.29, 17.8
(KAIT).
P. A. Milne, University of Arizona; and S. B. Cenko, University of
California, Berkeley, report that inspection of a CCD spectrum (range 400-830
nm), obtained on Feb. 13 UT with the 2.3-m Bok telescope (+ Boller and Chivens
spectrograph), shows that 2011ac is a type-Ia supernova. After removal of the
host-galaxy recession velocity of 14030 km/s (Falco et al. 1999, PASP 111,
438; via NED), they find the absorption minimum of the Si II 635.5-nm line to
be blueshifted by about 12000 km/s. Cross-correlation with a library of
supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and
Tonry 2007, Ap.J. 666, 1024) indicates that 2011ac is a normal type-Ia
supernova shortly before maximum light.
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2011 CBAT
2011 February 14 (CBET 2655) Daniel W. E. Green
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