SWS Central Program--- Stars (110 hr; 25%)
- Gas/dust debris disks around YSO's
- Are all young stars surrounded by dusty disks?
- How does gas & dust evolve as stars approach main sequence?
- What termines time-scale for dispersal of material?
- How do massive disks evolve into low-mass Beta Pic discs?
- Is planet formation common or exceptional in such disks?
- MS & Post-MS evolution of massive OB stars
(Waters; Lamers; van der Hutch).
- Mass loss drives evolution: Wolf-Rayet vs. red supergiant, etc.
- Mass outflows studied via HI, HeI, HeII recombination lines,
forbidden lines, and free-free continuum.
- Mass loss mechanism, mass loss rate, abundances.
- Post-MS evolution of low & intermediate mass stars
(de Jong; Waters; Beintema).
- Evolution on AGB and beyond is driven by slow, dusty winds.
- The mass loss rate exceeds nuclear burning rate by as much as 10X.
- Determine AGB mass loss dependence on mass, lum. and composition.
- No reliable theory for AGB mass loss yet exists.