Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002a%26a...390.1049b&link_type=abstract
Astronomy and Astrophysics, v.390, p.1049-1061 (2002)
Astronomy and Astrophysics
Astrophysics
19
Line: Profiles, Stars: Atmospheres, Stars: Chromospheres, Stars: Activity, Stars: Winds, Outflows
Scientific paper
We investigate a chromospheric scenario to explain the characteristics of the far-UV emission lines of beta Pictoris, revealed by FUSE spectra of this famous circumstellar disk system. The model assumes a thin region heated up to a few 105 K located close to the stellar photosphere. The resonance lines of C III at 977 Å and O VI at 1032-1037 Å, seen in emission, are produced in this chromosphere-transition region complex. Using complementary data in the mid and near UV (specifically, a resonance doublet of C IV at 1548-1550 Å and Mg II h & k), we show that the whole dataset is remarquably well reproduced by the model. In addition, we investigate the properties of the C III* multiplet at 1176 Å and conclude that this line likely forms in a weak warm wind, originating from the prominent circumstellar disk of beta Pictoris. Finally, radiative losses have been calculated and have provided estimates of the amount of non radiative energy dissipated in the external atmosphere of beta Pictoris, which is a measure of the star's activity level. Such behavior for an A5 V star presents a challenge for both evolution and activity models since the former predict that main-sequence A stars should not be active, while the latter are unable to quantitatively account for the characteristics of the chromospheric heating of beta Pictoris.
Bouret Jean-Claud
Deleuil Magali
Lanz Thierry
Lecavelier Des Etangs Alain
Roberge Aki
No associations
LandOfFree
A chromospheric scenario for the activity of beta Pictoris, as revealed by FUSE 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 A chromospheric scenario for the activity of beta Pictoris, as revealed by FUSE, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A chromospheric scenario for the activity of beta Pictoris, as revealed by FUSE will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1673039