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Model Stellar Atmospheres and Real Stellar Atmospheres and Status of the ATLAS12 Opacity Sampling Program and of New Programs for Rosseland and for Distribution Function OpacityI discuss errors in theory and in interpreting observations that are produced by the failure to consider resolution in space, time, and energy. I discuss convection in stellar model atmospheres and in stars. Large errors in abundances are possible such as the factor of ten error in the Li abundance for extreme Population II stars. Finally I discuss the variation of microturbulent velocity with depth, effective temperature, gravity, and abundance. These variations must be dealt with in computing models and grids and in any type of photometric calibration. I have also developed a new opacity-sampling version of my model atmosphere program called ATLAS12. It recognizes more than 1000 atomic and molecular species, each in up to 10 isotopic forms. It can treat all ions of the elements up through Zn and the first 5 ions of heavier elements up through Es. The elemental and isotopic abundances are treated as variables with depth. The fluxes predicted by ATLAS12 are not accurate in intermediate or narrow bandpass intervals because the sample size is too small. A special stripped version of the spectrum synthesis program SYNTHE is used to generate the surface flux for the converged model using the line data on CD-ROMs 1 and 15. ATLAS12 can be used to produce improved models for Am and Ap stars. It should be very useful for investigating diffusion effects in atmospheres. It can be used to model exciting stars for H II regions with abundances consistent with those of the H II region. These programs and line files will be distributed on CD-ROMs.
Document ID
19970028945
Acquisition Source
Headquarters
Document Type
Preprint (Draft being sent to journal)
Authors
Kurucz, Robert L.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1996
Subject Category
Astrophysics
Report/Patent Number
NAS 1.26:205489
Preprint-4372
NASA-CR-205489
Meeting Information
Meeting: Model Atmospheres and Spectrum Synthesis
Location: Vienna
Country: Austria
Start Date: July 6, 1995
End Date: July 11, 1995
Accession Number
97N27657
Funding Number(s)
CONTRACT_GRANT: NAGw-2528
CONTRACT_GRANT: NAGw-3299
CONTRACT_GRANT: NAGw-1486
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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