ZTF Early Observations of Type Ia Supernovae I: Properties of the 2018 Sample

Understand

Early-time observations of Type Ia supernovae (SNe Ia) are essential to constrain their progenitor properties.

• In this paper, we present high-quality light curves of 127 SNe Ia discovered by the Zwicky Transient Facility (ZTF) in 2018.
• We describe our method to perform forced point spread function (PSF) photometry, which can be applied to other types of extragalactic transients.
• With a planned cadence of six observations per night ($3g+3r$), all of the 127 SNe Ia are detected in both $g$ and $r$ band more than 10\,d (in the rest frame) prior to the epoch of $g$-band maximum light.