Details

Autor(en) / Beteiligte

• Haisch, Bernhard M.
• Bookbinder, Jay A.
• Maggio, A.
• Vaiana, G. S.
• Bennett, Jeffrey O.

Titel

IUE and Einstein survey of late-type giant and supergiant stars and the dividing line

Ist Teil von

• The Astrophysical journal, 1990-10, Vol.361 (2), p.570-589

Ort / Verlag

Legacy CDMS: University of Chicago Press

Erscheinungsjahr

1990

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Results are presented on an IUE UV survey of 255 late-type G, K, and M stars, complementing the Maggio et al. (1990) Einstein X-ray survey of 380 late-type stars. The large data sample of X-ray and UV detections make it possible to examine the activity relationship between the X-ray and the UV emissions. The results confirm previous finding of a trend involving a steeply-dropping upper envelope of the transition region line fluxes, f(line)/f(V), as the dividing line is approached. This suggests that a sharp decrease in maximum activity accompanies the advancing spectral type, with the dividing line corresponding to this steep gradient region. The results confirm the rotation-activity connection for stars in this region of the H-R diagram.