Revealing the Progenitor of SN 2021zby through Analysis of the TESS Shock-cooling Light Curve

Journal article

Abstract We present early observations and analysis of the double-peaked Type IIb supernova (SN IIb) SN 2021zby. TESS captured the prominent early shock-cooling peak of SN 2021zby within the first ∼10 days after explosion with a 30 minute cadence. We present optical and near-infrared spectral series of SN 2021zby, including three spectra during the shock-cooling phase. Using a multiband model fit, we find that the inferred properties of its progenitor are consistent with a red supergiant or yellow supergiant, with an envelope mass of ∼0.30–0.65 M ⊙ and an envelope radius of ∼120–300 R ⊙. These inferred progenitor properties are similar to those of other SNe IIb with a double-peaked feature, such as SNe 1993J, 2011dh, 2016gkg, and 2017jgh. This study further validates the importance of the high cadence and early coverage in resolving the shape of the shock-cooling light curve, while the multiband observations, particularly UV, are also necessary to fully constrain the progenitor properties.

Authors: Wang, Q; Armstrong, P; Zenati, Y; Ridden-Harper, R; Rest, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Astronomical Society
• Journal: The Astrophysical Journal Letters
• Volume: 943
• Issue: 2
• Pages: L15-L15
• Publication date: 2023-01-31
• DOI: 10.3847/2041-8213/acb0d0
• EISSN: 2041-8213
• ISSN: 2041-8205
• Language: English
• Keywords: Acoustics; Envelope (radar); Computer science; Red supergiant; Physics; Cadence; Light curve; Astrophysics; RADIUS; Shock (circulatory); Stars; Supernova; Supergiant