The Carnegie Supernova Project: First Photometry Data Release of Low-Redshift Type Ia Supernovae

Abstract

The Carnegie Supernova Project is a five-year survey being carried out at the Las Cam- panas Observatory to obtain high-quality light curves of 100 low-redshift Type Ia supernovae in a well-defined photometric system. Here we present the first release of photometric data that contains the optical light curves of 35 Type Ia supernovae, and near-infrared light curves for a subset of 25 events. The data comprise 5559 optical (ugriBV ) and 1043 near-infrared (Y JHKs) data points in the natural system of the Swope telescope. Twenty-eight supernovae have pre-maximum data, and for 15 of these, the observations begin at least 5 days before B maximum. This is one of the most ac- curate datasets of low-redshift Type Ia supernovae published to date. When completed, the CSP dataset will constitute a fundamental reference for precise determinations of cosmological parameters, and serve as a rich resource for comparison with models of Type Ia supernovae.