VLBA Observations of The Birth, Life, and Death of Stars

Mark Claussen

The tenth anniversary of the dedication of NRAO's Very Long Baseline Array is approaching, so I use the opportunity to review observations of radio sources which probe the stellar life cycle of stars of different masses. The VLBA provides the highest angular resolution of any astronomical instrument on the Earth or in space. It is continuously available, and has outstanding imaging capability.

In the very early and very late stages of stellar evolution the observation of naturally occurring maser emission allows kinematic and dynamic probes of the molecular gas surrounding the stars at very high angular and velocity resolution. In between these stages many stars emit non-thermal radio emission, likely due to magnetic activity (gyrosynchrotron radiation) or colliding winds in binary systems. I will review VLBA observations of several of these stellar scenarios, highlighting the strengths of the VLBA and synergy with other wavelength observations.