Spicular downflows and the transition to high mass-loss rates in G and K giants

Journal Article · Wed Oct 01 04:00:00 EDT 1980 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/158335· OSTI ID:6919143

Wallenhorst, S G

The mass-loss rates and coronal base pressures of stars that have evolved up to and beyond the so-called high mass-loss rate transition locus have been examined, using an energy-balance model in which the coronal energy losses due to downflowing spicular material are included. The minimum flux assumption of A.G. Hearn is used to evaluate the jump in mass-loss rate expected when the sonic point of the stellar wind reaches the coronal base. An order-of-magnitude increase in mass-loss rate is predicted. In addition, this jump in mass-loss rate is estimated, using a temperature-height profile for a transition region dominated by spicular downflows to estimate tha amount of downflowing material. Both methods give similar results, leading to the conclusion that as a star evolves across the transition locus, an order-of-magnitude increase in stellar mass-loss rate is to be expected.

• Research Organization: Washburn Observatory, University of Wisconsin, Madison
• OSTI ID: 6919143
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 241:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
DATA
DIAGRAMS
GIANT STARS
HERTZSPRUNG-RUSSELL DIAGRAM
INFORMATION
MASS TRANSFER
NUMERICAL DATA
STARS
STELLAR ATMOSPHERES
THEORETICAL DATA