AAS 201st Meeting, January, 2003
Session 12. Activity in Cool Stars
Poster, Monday, January 6, 2003, 9:20am-6:30pm, Exhibit Hall AB

[Previous] | [Session 12] | [Next]

[12.02] XMM-NEWTON/RGS First View of Coronas of Two Luminous Cool Stars

A. K. Dupree, N. S. Brickhouse (Harvard-Smithsonian CfA)

Two single cool stars, \beta Dra (G2Ib--IIa, HD 159181) and \alpha TrA (K2 II--III, HD 150798) offer a contrast in the structure and evolution of their outer atmospheres. Alpha TrA is a well-known hybrid object, from a class of cool luminous single stars originally identified based on the presence of strong C IV emission accompanied by absorption features at low and high velocities indicating a massive stellar wind and circumstellar material. The atmosphere of Beta Dra appears to be similar to the solar coronal example with high temperature emission, but lacking a massive cool wind. X-Ray observations can help to delineate structure and evolution of stellar coronae from the solar example through the intermediate hybrid configuration. Spectra of these stars obtained with XMM/Newton under the Guest Investigator program contain emission lines of many elements and ionic species. An emission measure distribution is constructed from a line-based analysis. Differences in structure, density, and element abundance between the coronas of these luminous stars are quantified. This research is supported in part by a NASA Grant NAG5-9977 to the Smithsonian Astrophysical Observatory.

[Previous] | [Session 12] | [Next]

Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.