Abstract

Massive stars are rare beasts but they contribute copious energy, mass and momentum to the interstellar medium and thus are crucial to the evolution of galaxies. They also produce many of elements that make life on Earth possible, such as the oxygen in our atmosphere and the iron in our blood. In some ways, massive stars resemble simple, “one-dimensional” stars. However, recent observational discoveries have led us to rethink our basic understanding of these objects. More massive stars are in close, potentially interacting or interacted, binary-star systems than was previously thought. Some are very rapidly rotating and some are chemically mixed. Theory predicts that spin and mixing correlate: but sometimes the opposite is seen. Binary-stars can probably explain the massive-star spin distribution, as well as their peculiar chemical abundances, and our modelling efforts are just starting to bear fruit in this field. I will review the properties of massive stars before expanding on some recent highlights in regard to stellar spins, the stellar mass function, and the relation between chemistry and duplicity in massive stars. Finally, there will be an administrative announcement.