Physics
Scientific paper
Apr 1991
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991apj...370..693c&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 370, April 1, 1991, p. 693-708. Research supported NSERC and Ministere de l
Physics
67
A Stars, F Stars, Stellar Interiors, Stellar Physics, Abundance, Convection, Finite Element Method, Metallicity, Particle Diffusion, Stellar Models, Transport Properties, Turbulence
Scientific paper
Time-dependent two-dimensional calculations of diffusion in the presence of meridional circulation are presented for stellar models pertaining to FmAm stars. It is shown that, once the helium superficial convection zone (HSCZ) has disappeared, the meridional circulation has little influence on chemical separation. In stars rotating too rapidly to become FmAm stars, chemical separation remains possible under the HSCZ. Meridional circulation does not completely wipe out chemical separation at these velocities, and cannot by itself lead to the abundance patterns characteristic of Lambda Booti stars. Upper limits to turbulence are set. In the presence of meridional circulation, helium settling in stars rotating at the observed cutoff for FmAm stars remains possible for values of vertical turbulent diffusion coefficients of order 1000 sq cm/s under the helium convection zone. This sets extremely tight constraints on turbulence in stars with equatorial rotational velocities of 100 km/s or less.
Charbonneau Paul
Michaud Georges
No associations
LandOfFree
Meridional circulation and diffusion in A and early 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 Meridional circulation and diffusion in A and early F stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Meridional circulation and diffusion in A and early F stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1790167