Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-08-24
Astronomy and Astrophysics
Astrophysics
11 pages, 8 figures, submitted to Astronomy Astrophysics main Journal
Scientific paper
10.1051/0004-6361:20011117
IUE observations of the eclipsing binary system HR 6902 obtained at various epochs spread over four years indicate the presence of warm circumstellar material enveloping the G9 IIb primary. The spectra show Si IV and C IV absorption up to a distance of 3.3 giant radii (R_g}. Line ratio diagnostics yields an electron temperature of ~ 78000 K which appears to be constant over the observed height range. Applying a least square fit absorption line analysis we derive column densities as a function of height. We find that the inner envelope (< 3 R_g) of the bright giant is consistent with a hydrostatic density distribution. The derived line broadening velocity of ~ 70 kms^{-1} is sufficient to provide turbulent pressure support for the required scale height. However, an improved agreement with observations over the whole height regime including the emission line region is obtained with an outflow model. We demonstrate that the common beta power-law as well as a P \propto rho wind yield appropriate fit models. Adopting a continuous mass outflow we obtain a mass-loss rate of M_loss= (0.8 - 3.4)*10^{-11} M_{sun}yr^{-1} depending on the particular wind model.
Baade Robert
Kirsch Thomas
Reimers Dieter
No associations
LandOfFree
The warm circumstellar envelope and wind of the G9 IIb star HR 6902 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The warm circumstellar envelope and wind of the G9 IIb star HR 6902, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The warm circumstellar envelope and wind of the G9 IIb star HR 6902 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-346569