Astronomy and Astrophysics – Astrophysics
Scientific paper
2002-07-18
Astronomy and Astrophysics
Astrophysics
11 pages, 4 figures, 2 tables. To appear in proceedings of IAU Symp. 210, "Modelling of Stellar Atmospheres", ASP Conference S
Scientific paper
Balmer lines are an important diagnostic of stellar atmospheric structure, since they are formed at a wide range of depths within the atmosphere. The different Balmer lines are formed at slightly different depths making them useful atmospheric diagnostics. The low sensitivity to surface gravity for stars cooler than ~8000 K makes them excellent diagnostics in the treatment of atmospheric convection. For hotter stars Balmer profiles are sensitive to both effective temperature and surface gravity. Provided we know the surface gravity of these stars from some other method (e.g. from eclipsing binary systems), we can use them to determine effective temperature. In previous work, we have found no significant systematic problems with using uvby photometry to determine atmospheric parameters of fundamental (and standard) stars. In fact, uvby was found to be very good for obtaining both Teff and log g. Using Halpha and Hbeta profiles, we have found that both the Canuto & Mazzitteli and standard Kurucz mixing-length theory without approximate overshooting are both in agreement to within the uncertainties of the fundamental stars. Overshooting models were always clearly discrepant. Some evidence was found for significant disagreement between all treatments of convection and fundamental values around 8000~9000K, but these results were for fundamental stars without fundamental surface gravities. We have used stars with fundamental values of both Teff and log g to explore this region in more detail.
Kupka Friedrich
Smalley Barry
No associations
LandOfFree
Using Balmer line profiles to investigate convection in A and F stars 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 Using Balmer line profiles to investigate convection in A and F stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Using Balmer line profiles to investigate convection in A and F stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-209099