ESC observations of SN 2005cf – I. Photometric evolution of a normal Type Ia supernova

Abstract

We present early-time optical and near-infrared photometry of supernova (SN) 2005cf. The observations, spanning a period from about 12 d before to 3 months after maximum, have been obtained through the coordination of observational efforts of various nodes of the European Supernova Collaboration and including data obtained at the 2-m Himalayan Chandra Telescope. From the observed light curve we deduce that SN 2005cf is a fairly typical SN Ia with a post-maximum decline [Δm15(B)true = 1.12] close to the average value and a normal luminosity of MB,max = −19.39 ± 0.33. Models of the bolometric light curve suggest a synthesized 56Ni mass of about 0.7 Mo. The negligible host galaxy interstellar extinction and its proximity make SN 2005cf a good Type Ia SN template.