Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Mass loss from evolved stars

Thesis/Dissertation ·
OSTI ID:6935240

This work consists of two studies of the matter that flows outward from the surface of stars that have reached the late stages of evolution. This process of mass loss is important to the understanding of the continued evolution of the star and the replenishment of the interstellar medium from which the next generation of stars will form. The two major constituents of these circumstellar envelopes are gaseous molecules and solid dust grains, both of which form in the outflow as the matter expands and cools. Each of these components is investigated separately. From the gaseous molecule observations, estimates of mass loss rates, envelope sizes, molecular abundances, and isotope ratios are derived in an attempt to understand the composition, kinematics, and chemistry of the molecular component of the mass flow. The solid component of the mass flow is investigated by means of broad-band submillimeter observations of the thermal emission from dust in the circumstellar envelope. These circumstellar dust data, which include the 400-..mu..m data, provides reasonably strong evidence that the grains in both carbon-rich and oxygen-rich envelopes are not crystalline but are composed of amorphous structures.

Research Organization:
Maryland Univ., College Park (USA)
OSTI ID:
6935240
Country of Publication:
United States
Language:
English