Which are the most massive stars and how massive are they?
Fundamental questions of stellar astrophysics suffer from an almost complete
lack of truly empirical evidence when it comes to stars with the highest
masses both on and evolved off the main sequence. Recent theoretical and
observational work suggests that the most massive stars known are to be
found not among bright O stars, but among a luminous, hydrogen-rich subgroup
of Wolf-Rayet stars, the so-called WN5-7ha stars, which, despite their being
near the upper main-sequence, are able to drive strong winds due to their
extreme luminosities. Directly weighing such objects by Keplerian orbits in
binaries is the only way to obtain reliable masses for these stars. I will
present results that have been obtained from the study of spectroscopic
binaries, and present the most massive stars known so far.
Back to the seminar webpage.
