Computer Science
Scientific paper
Dec 2004
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004iaus..224..173m&link_type=abstract
The A-Star Puzzle, held in Poprad, Slovakia, July 8-13, 2004. Edited by J. Zverko, J. Ziznovsky, S.J. Adelman, and W.W. Weiss,
Computer Science
16
Convection, Diffusion, Turbulence, Stars: Abundances, Stars: Atmospheres, Stars: Chemically Peculiar, Stars: Evolution, Stars: Horizontal-Branch, Stars: Interiors, Stars: Magnetic Fields, Stars: Mass Loss.
Scientific paper
Atomic diffusion may play a significant role for the Sun and Population I Main Sequence stars up to some 25000 K, Population II turnoff stars and cluster age determinations, horizontal branch stars (including sdOs and sdBs), white dwarfs and neutron stars. In all these cases, radiative accelerations play a significant role. A stars are, however, arguably those that show most prominently the effects of atomic diffusion. In so far as the effects of accretion, mass loss, turbulence and meridional circulation may be neglected in the evolutionary models of A stars, the effects of atomic diffusion in them have now been calculated from first principles and are presented using complete evolutionary models of 1.7 and 2.5 M&sun; stars. Their abundance anomalies are not only superficial, but extend over a significant fraction of the stellar radius. Iron convection zones appear at a temperature of about 200000 K. Abundance anomalies similar to those observed in Am stars are produced. However the comparison with the observations requires linking atmospheres to interior evolution. Models that have been proposed to take into account atomic diffusion in atmospheric regions to explain observations are critically reviewed. They depend on a number of parameters. Unfortunately the atmospheric regions are imperfectly modeled, the magnetic field is not taken into account, and important hydrodynamic processes currently require arbitrary parameters for their description.
No associations
LandOfFree
Atomic diffusion in stellar surfaces and interiors 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 Atomic diffusion in stellar surfaces and interiors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Atomic diffusion in stellar surfaces and interiors will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1083076