Advanced stages of massive stars evolution

Massive stars end their lives as powerful supernova explosions which acts to both synthesise chemical elements and inject energy into the surrounding environment. Core collapse supernova explosions have diverse properties and are observed to have a range of different progenitors. The majority of massive stars are predicted to explode as supernova as a red supergiant star (RSG). In this area we are interested in the physical properties of RSGs including their multiplicity properties and how binary interactions affect stellar endpoints. One of the key outstanding questions in this area is the so-called Red Supergiant Problem, which is a mismatch between the stars that we observe in the Local Universe and the mass distribution of the supernova that these stars supposedly produce. Our group at the CAB works towards solving this problem by studying RSG populations in external galaxies, particularly in the Magellanic Clouds.

This artist’s impression shows the yellow hypergiant star HR 5171. This is a very rare type of star with only a dozen known in our galaxy. Its size is over 1300 times that of our Sun — one of the largest ten stars found so far. Observations with ESO’s Very Large Telescope Interferometer have shown that it is actually a double star, with the companion being a potential red supergiant star.