Massive stars dying alone: the remote environment of supernova 2010jp and its associated late-time source

ABSTRACT We present late-time images of the site of the peculiar jet-driven Type IIn supernova (SN) 2010jp, including Hubble Space Telescope images taken 2–5 yr post-explosion and deep ground-based images over a similar time. These are used to characterize its unusually remote environment and to constrain the progenitor’s initial mass and age. The position of SN 2010jp is found to reside along a chain of diffuse starlight that is probably an outer spiral arm or tidal tail of the interacting galaxy pair NGC 2207/IC 2163. There is one bright H ii region projected within 1 kpc, and there is faint extended H α emission immediately surrounding the continuum source at the position of SN 2010jp, which has MF555W = −7.7 ± 0.2 mag. In principle, the lingering light could arise from late-time circumstellar material (CSM) interaction, an evolved supergiant, a host star cluster, or some combination of these. Steady flux over 3 yr and a lack of strong, spatially unresolved H α emission make ongoing CSM interaction unlikely. If an evolved supergiant dominates, its observed luminosity implies an initial mass $\lesssim\!{22}$ M⊙ and an age $\gtrsim\!{8}$ Myr. If the source is a star cluster, then its colour and absolute magnitude imply an age of 8–13 Myr and a modest cluster initial mass of log(M/M⊙) = 3.6–3.8. Extended H α emission out to a radius of ∼30 pc reveals a faint evolved H ii region, pointing to recent star formation with at least one late O-type star. Based on these various clues, we conclude that the progenitor of SN 2010jp had a likely initial mass of 18–22 M⊙.