Speaker
Description
Despite the traditional model of a Yellow Supergiant as a brief transitional phase in a star’s life before the onset of core helium burning, there is an increasing catalog of supernovae explosions that have had their progenitors identified as Yellow Supergiants from pre-explosion imaging. Notably, these supernovae are both partially-stripped and hydrogen-poor. The widespread interpretation for these observations is that a binary companion partially strips the supernova progenitor of its stellar envelope, after which it subsequently explodes as a Yellow Supergiant, having the appropriate temperatures and luminosities for this regime. Still, no analogs to these partially-stripped Yellow Supergiants have been discovered in Local Group galaxies that can be studied in detail prior to their explosion. Theoretical models predict that certain pulsations should be excited exclusively in partially stripped Yellow Supergiants, resulting in unique lightcurve morphology. Therefore, the variability of Yellow Supergiants can provide unique insight into their stellar structure and the presence of a full or partially-stripped hydrogen envelope. I will describe the ongoing program to characterize the variability of hundreds of YSGs in the Magellanic Clouds with the goal of finding potential partially-stripped Yellow Supergiants. In particular, I will highlight the identification of candidate Yellow Supergiants to date that have the predicted hallmarks of partially stripping, and describe on-going follow-up efforts to confirm the nature of this sub-population.
