SUPERNOVA
2011C IN UGC 6311
J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, R. Cartier,
F. Forster, S. Silva, F. Carrasco, P. Sanchez, and C.
Hervias, Universidad de Chile; G. Pignata and M. Cifuentes,
Universidad Andres Bello; P. Gonzalez, 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, report the discovery
of an apparent supernova (mag approximately 15.8) on
an unfiltered image taken on Jan. 5.30 UT with the 0.41-m
'PROMPT 5' telescope located at Cerro Tololo. The new
object, which was confirmed at mag approximately 15.4
in an image taken with the 'PROMPT 5' telescope on Jan.
7.26, is located at R.A. = 11h17m54s.88 +/- 0".3, Decl.
= -2°05'45".2 +/- 0".3 (equinox 2000.0), which is about
1".4 west and 14".4 south of the center of the galaxy
UGC 6311. Nothing is visible at this position on archival
images taken on 2010 May 4.05 and Dec. 17.30 (limiting
mag 18.0).
Following posting on the Central Bureau's unconfirmed-objects
webpage, D. D. Balam, Dominion Astrophysical Observatory,
National Research Council of Canada; M. L. Graham, Las
Cumbres Observatory Global Telescope, University of
California at Santa Barbara; and E. Y. Hsiao, Lawrence
Berkeley Laboratory, report that a spectrogram (range
385-694 nm, resolution 0.3 nm) of 2011C, obtained on
Jan. 8.58 UT with the 1.82-m Plaskett Telescope of the
National Research Council of Canada, shows it to be
a type-Ia supernova about one week past maximum light.
Cross-correlation with a library of supernova spectra
using the "Supernova Identification" code (Blondin and
Tonry 2007, Ap.J. 666, 1024) indicates that 2011C is
most similar to the type-Ia supernova 2003cg at 6 days
past maximum; the redshift derived from their fit is
0.025. . |