2 research outputs found
The Early Light Curve of a Type Ia Supernova 2021hpr in NGC 3147: Progenitor Constraints with the Companion Interaction Model
The progenitor system of Type Ia supernovae (SNe Ia) is expected to be a
close binary system of a carbon/oxygen white dwarf (WD) and a non-degenerate
star or another WD. Here, we present results from a high-cadence monitoring
observation of SN 2021hpr in a spiral galaxy, NGC 3147, and constraints on the
progenitor system based on its early multi-color light curve data. First, we
classify SN 2021hpr as a normal SN Ia from its long-term photometric and
spectroscopic data. More interestingly, we found a significant "early excess"
in the light curve over a simple power-law evolution. The early
light curve evolves from blue to red and blue during the first week. To explain
this, we fitted the early part of -band light curves with a two-component
model of the ejecta-companion interaction and a simple power-law model. The
early excess and its color can be explained by shock cooling emission due to a
companion star having a radius of . We also examined
HST pre-explosion images with no detection of a progenitor candidate,
consistent with the above result. However, we could not detect signs of a
significant amount of the stripped mass from a non-degenerate companion star
( for H emission). The early excess light in
the multi-band light curve supports a non-degenerate companion in the
progenitor system of SN 2021hpr. At the same time, the non-detection of
emission lines opens a door for other methods to explain this event.Comment: 26 pages, 13 figures + appendix, Accepted for publication in Ap