Massive stars and stellar populations
Introduction
Massive stars in all phases of their life influence their environments very strongly via radiation, winds, and their violent deaths. Understanding these stars, and populations of them, from birth to death therefore elucidates many key processes of our origins, such as the cycle of star birth and galaxy evolution, the origin of the elements (especially those needed for life).
Stellar interactions in binaries, triples or higher-order multiples give rise to many of the extreme phenomena mentioned above, such as:
- X-ray binaries
- gamma-ray bursts,
- gravitational-wave sources
These provide a natural link between the HEA and ORI sections of the institute.
How we study hot stars
We use optical/infra-red spectroscopic and automated transient surveys. These observations improve our theories on the role of:
-stellar winds
-internal mixing processes
-binary interaction.
Optical/IR spectroscopic study of hot stars is the observational backbone of this theme, complemented by automated transient surveys probing the more violent phases of stellar evolution, and as of recently, gravitational-wave detections.
On the theory side, we use stellar evolution codes, detailed as well as fast codes, to study the formation and evolution of stars. Particular focus is given to stellar interactions in binaries & triples, as well as the role of stellar winds and mixing processes.
Future
We want to move well out of our own Galaxy to probe other populations of massive stars. This will improve our models on the evolution of galaxies and colliding massive stars and their remnants.
New frontiers in this field are a full exploration of the wide range of physics effects that influence (binary) stellar evolution, backed up by moving well out of our own Galaxy to probe populations of massive stars in a wide range of galactic environments.
This will both test and constrain stellar models and allow precise constraints on their evolution.
Keywords
Massive stars, star birth, galaxy evolution, hot stars, optical/infra-red spectroscopy, stellar winds, internal mixing, binary interaction
Facilities
Now: VLT, WHT, HST, aLIGO, GAIA, (software) MESA
Future: E-ELT, JWST, BlackGem, transient survey machines