Supernova 2009ib in NGC 1559

G. Pignata, Universidad Andres Bello; J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, P. Gonzalez, P. Lopez, S. Silva, G. Folatelli, D. Iturra, R. Cartier, F. Forster, S. Marchi and A. Rojas, Universidad de Chile; B. Conuel, Wesleyan University; and D. Reichart, K. Ivarsen, 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 in NGC 1559 (mag approximately 14.7 +/- 0.2) on an R-band image taken on Aug. 6.30 UT with the 0.41-m "PROMPT 5" telescope located at Cerro Tololo Interamerican Observatory. In the image the candidate supernova is located at R.A. = 4h17m39s.92 +/- 0".1, Decl. = -62d46'38".7 +/- 0".1 (equinox J2000.0), which is about 28".5 east and 22".3 north of the center of the galaxy. Nothing is visible at the candidate's location on archival images taken on Feb. 21.05 (limiting mag 18.0) and Feb. 4.15 (limiting mag 18.5). NGC 1559 is also the host galaxy of supernovae 1984J, 1986L and 2005df. M. Stritzinger, Las Campanas Observatory; and G. Folatelli, Universidad de Chile, on behalf of the Millennium Center for Supernova Science, report that they obtained an optical spectrum of the candidate supernova in NGC 1559 on Aug. 9.1 UT with the Gemini (+ GMOS) telescope. The spectrum reveals that the supernova is of type IIP. Comparison with a library of spectra via the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Astrophys. J. 666, 1024) indicates that this supernova is most nearly similar to supernova 2005cs a week after explosion.