Dusty post-red giant branch stars (post-RGB) stars in the Magellanic Clouds

Abstract

In our recent search for post-AGB stars in the Magellanic Clouds, we discovered a new class of low-luminosity, low-metallicity, dusty, evolved objects. These objects have dust excesses, stellar parameters and spectral energy distributions similar to those of dusty post-Asymptotic Giant Branch (post-AGB) stars. However, they have lower luminosities and hence smaller masses. We suggest that they have evolved off the Red Giant Branch (RGB) instead of the AGB as a result of binary interaction. Galactic counterparts are not known due to the poorly constrained distances of dusty post-AGB-like objects in the Galaxy. Here, we present the first observational evidence these new dusty, low-luminosity “post-RGB” objects and we aim to place these objects in an evolutionary context.