SUPERNOVA 2009nb G. Pignata, Universidad Andres Bello; J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, P. Gonzalez, P. Lopez, S. Silva, G. Folatelli, R. Cartier, F. Forster, S. Marchi, and A. Rojas, Universidad de Chile; B. Conuel, Wesleyan University; 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 18.3 +/- 0.4) on an unfiltered image taken on Dec. 25.27 UT with the 0.41-m 'PROMPT 4' telescope located at Cerro Tololo. The new object, which is also present in a stack of eleven 40-s images taken on Dec. 26.21 (at mag approximately 18.5) and Dec. 20.26 (at mag approximately 18.4), is located at R.A. = 10h28m04s.68 +/- 0".1, Decl. = -35°30'02".2 +/- 0".1 (equinox 2000.0), which is about 4".6 east and 2".3 north of the center of the apparent host galaxy. Nothing is visible at this position a stack of thirty-six 40-s archival images taken with the same instrument between 2008 Dec. 25.26 and 2009 Nov. 22.29 (limiting mag 21.0).

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

2009 December 27

(C) Copyright 2009 CBAT (CBET 2099)

Daniel W. E. Green