Electronic Telegram No. 2503

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

SUPERNOVAE 2010iu AND 2010iv
J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, R. Cartier, and F. Forster, Universidad de Chile; G. Pignata and M. Cifuentes, Universidad Andres Bello; P. Gonzalez, Pontificia Universidad Catolica de Chile; B. Conuel, Wesleyan University; G. Folatelli, Institute for the Physics and Mathematics of the Universe (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 17.4) on unfiltered images taken on Oct. 15.26 and 16.09 UT with the 0.41-m 'PROMPT 1' telescope located at Cerro Tololo. The object, designated SN 2010iv, is located at R.A. = 4h03m52s.23 +/- 0".2, Decl. = -43°25'38".5 +/- 0".2 (equinox 2000.0); it is right on the top of the small galaxy and completely dominating the visible light. Nothing is visible at this position on a stack of seventeen 40-s archival images taken between 2009 Nov. 5.13 and 2010 Aug. 13.28 (limiting mag 19.5).
G. Pignata, Universidad Andres Bello; and G. Folatelli, IPMU, University of Tokyo, on behalf of the Millennium Center for Supernova Science, report on optical spectroscopy (range 355-890 nm) of 2010iv (see above) and the object announced on CBET 2499 (and now designated 2010iu), obtained with the SOAR 4.3-m telescope (+ Goodman HTS) on Oct. 16.3 UT. The spectra show both objects to be normal type-Ia supernovae, a few days before maximum. Following cross-correlation with a library of supernova spectra using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024), 2010iv is found to be most similar to SN 2003du at three days before maximum; SNID also provides a best-fit redshift of 0.074 for 2010iv. SN 2010iu is most similar to SN 1992A at five days before maximum (via SNID). The Si II 597.2-nm line appears stronger in SN 2010iu than in SN 1992A. SNID also provides a best-fit redshift of 0.040 for SN 2010iu. .

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

2010 October 17
(C) Copyright 2010 CBAT
(CBET 2503 )
Daniel W. E. Green