Electronic Telegram No. 2661

Central Bureau for Astronomical Telegrams
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138,
U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://www.cfa.harvard.edu/iau/cbat.html

SUPERNOVA 2011ah IN ESO 364-12 = PSN J05535077-3244442
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; 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 16.0) on an unfiltered image taken on Feb. 5.15 UT with the 0.41-m 'PROMPT 1' telescope located at Cerro Tololo. The new object (which was designated PSN J05535077-3244442 when posted on the Central Bureau's TOCP webpage, and which is here designated SN 2011ah based on the spectroscopic report below) is located at R.A. = 5h53m50s.77 +/- 0".2, Decl. = -32o44'44".2 +/- 0".2 (equinox 2000.0), which is about 15".6 west and 7".2 south of the center of the galaxy ESO 364-12. Nothing is visible at this position on archival images taken on 2010 Dec. 31.25 (limiting mag 18.5) and 2011 Jan. 16.19 (limiting mag 18.0).

J. Anderson and F. Forster, Universidad de Chile; G. Pignata, Universidad Andres Bello; and G. Folatelli, University of Tokyo, on behalf of the Millennium Center for Supernova Science, report that they have obtained a spectrum (range 420-900 nm) of PSN J05535077-3244442 = SN 2011ah on Feb. 17.1 UT with the Magellan Baade 6.5-m telescope (+ IMACS) at Las Campanas Observatory. The spectrum indicates that 2011ah is a type-Ia supernova around a week after maximum; comparison with template spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) provides a close match to that of SN 1996C at eight days after maximum light. Adopting a host-galaxy recession velocity of 8094 km/s (Jones et al. 2009, 6DF Galaxy Survey Data Release 3) as reported via the NASA/IPAC Extragalactic Database, an expansion velocity of 12000 km/s is calculated from the absorption minimum of the Si II 635.5-nm line.

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

2011 Febrary 28
(C) Copyright 2010 CBAT
(CBET 2661)
Daniel W. E. Green