A Massive Progenitor of the Luminous Type IIn Supernova 2010jl

TL;DR

This paper investigates the progenitor of supernova SN2010jl, suggesting it originated from a very massive star over 30 solar masses, challenging existing stellar evolution models and highlighting the role of massive stars in Type IIn supernovae.

Contribution

It provides evidence that the progenitor of SN2010jl was a very massive star, supporting the idea that massive stars can produce luminous supernovae without collapsing quietly.

Findings

Progenitor likely had initial mass above 30 solar masses.

Massive stars can retain hydrogen envelopes until explosion.

Standard stellar models do not fully explain these observations.

Abstract

The bright, nearby, recently discovered supernova SN2010jl is a member of the rare class of relatively luminous Type~IIn events. Here we report archival HST observations of its host galaxy UGC5189A taken roughly 10yr prior to explosion, as well as early-time optical spectra of the SN. The HST images reveal a bright, blue point source at the position of the SN, with an absolute magnitude of -12.0 in the F300W filter. If it is not just a chance alignment, the source at the SN position could be (1) a massive young (less than 6 Myr) star cluster in which the SN resided, (2) a quiescent, luminous blue star with an apparent temperature around 14,000K, (3) a star caught during a bright outburst akin to those of LBVs, or (4) a combination of option 1 and options 2 or 3. Although we cannot confidently choose between these possibilities with the present data, any of them imply that the progenitor of SN2010jl had an initial mass above 30Msun. This reinforces mounting evidence that many SNe IIn result from very massive stars, that massive stars can produce visible SNe without collapsing quietly to black holes, and that massive stars can retain their H envelopes until shortly before explosion. Standard stellar evolution models fail to account for these observed properties.