Mr. Perez et Ca. Grady, OBSERVATIONAL OVERVIEW OF YOUNG INTERMEDIATE-MASS OBJECTS - HERBIG AEBE STARS/, Space science reviews, 82(3-4), 1997, pp. 407-450
Recent discoveries of planets orbiting several nearby solar-mass stars
have focussed renewed attention on the frequency and evolution of pla
netary systems and their evolutionary precursors around both solar and
intermediate (2 less than or equal to M/M-. less than or equal to 8)
mass stars. As a result of a wealth of new observations at all wavelen
gths of the circumstellar material around the nearest of the young int
ermediate-mass stars, the so-called Herbig Ae/Be (HAeBe) stars, we are
beginning to see how these systems are similar to the solar mass obje
cts, and how they differ. A review of the recent literature is present
ed, including the evolutionary status of the stars, binary frequency a
nd the star forming environment, the morphology of the circumstellar m
aterial, including the first direct detections of disks in Keplerian r
otation around these objects, and mass loss and infall phenomena. Pros
pects for advances in this research area as a result of advances in in
strumentation are reviewed.