2022MNRAS.511.3428K

With Gaia parallaxes, it is possible to study the stellar populations associated with individual Galactic supernova remnants (SNRs) to estimate the mass of the exploding star. Here, we analyse the luminous stars near the Vela pulsar and SNR to find that its progenitor was probably (> ∼ 90 percent) low mass (8.1-10.3 M_☉). The presence of the O star γ² Vel a little over 100 pc from Vela is the primary ambiguity, as including it in the analysis volume significantly increases the probability (to 5 per cent) of higher mass (> 20 M_☉) progenitors. However, to be a high-mass star associated with γ² Vel's star cluster at birth, the progenitor would have to be a runaway star from an unbound binary with an unusually high velocity. The primary impediment to analysing large numbers of Galactic SNRs in this manner is the lack of accurate distances. This can likely be solved by searching for absorption lines from the SNR in stars as a function of distance, a method which yielded a distance to Vela in agreement with the direct pulsar parallax. If Vela was a 10 M_☉ supernova in an external galaxy, the 50-pc search region used in extragalactic studies would contain only ≃10 percent of the stars formed in a 50-pc region around the progenitor at birth and ≃90 percent of the stars in the search region would have been born elsewhere.