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

## TL;DR

The CSP's first data release provides high-quality optical and near-infrared light curves for 35 low-redshift Type Ia supernovae, serving as a key resource for cosmology and supernova modeling.

## Contribution

This paper presents the initial release of a comprehensive, high-precision photometric dataset for low-redshift Type Ia supernovae, enhancing resources for cosmological studies.

## Key findings

- High-quality light curves for 35 supernovae are provided.
- Data includes optical and near-infrared observations with pre-maximum coverage.
- The dataset is among the most accurate for low-redshift Type Ia supernovae.

## Abstract

The Carnegie Supernova Project (CSP) is a five-year survey being carried out at the Las Campanas 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 (YJHKs) 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 accurate 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.