Photometric obs. of SN 2022ilv and SN 2020hvf

The Asteroid Terrestrial-impact Last Alert System light curve shows evidence of a short-lived, pulse-like early excess, similar to that detected in another luminous Type Ia supernova (SN 2020hvf). The light curve is broad, and the early spectra are remarkably similar to those of SN 2009dc.

Adopting a redshift of z=0.026+/-0.005 for SN 2022ilv based on spectral matching, our model light curve requires a large ^56^Ni mass in the range 0.7-1.5M_{sun}_ and a large ejecta mass in the range 1.6-2.3M_{sun}_. The early excess can be explained by fast-moving SN ejecta interacting with a thin, dense shell of circumstellar material close to the progenitor (~10^13^cm) a few hours after the explosion. This may be realized in a double-degenerate scenario, wherein a white dwarf merger is preceded by the ejection of a small amount (~10^-3^-10^-2^M_{sun}_) of hydrogen and helium-poor tidally stripped material.