# Early light curves for Type Ia supernova explosion models

## TL;DR

This study uses radiation hydrodynamical simulations to analyze early light curves of Type Ia supernova models, revealing similarities across models and challenges in identifying explosion mechanisms from early photometric data.

## Contribution

It provides synthetic early light curves for various Type Ia supernova models, highlighting the difficulty in distinguishing explosion scenarios using only early photometric observations.

## Key findings

- Early light curves are similar across models.
- Radioactive surface material leaves characteristic imprints.
- Power-law rise is not observed in most models.

## Abstract

Upcoming high-cadence transient survey programmes will produce a wealth of observational data for Type Ia supernovae. These data sets will contain numerous events detected very early in their evolution, shortly after explosion. Here, we present synthetic light curves, calculated with the radiation hydrodynamical approach Stella for a number of different explosion models, specifically focusing on these first few days after explosion. We show that overall the early light curve evolution is similar for most of the investigated models. Characteristic imprints are induced by radioactive material located close to the surface. However, these are very similar to the signatures expected from ejecta-CSM or ejecta-companion interaction. Apart from the pure deflagration explosion models, none of our synthetic light curves exhibit the commonly assumed power-law rise. We demonstrate that this can lead to substantial errors in the determination of the time of explosion. In summary, we illustrate with our calculations that even with very early data an identification of specific explosion scenarios is challenging, if only photometric observations are available.