Calculation tools and data for stellar evolution modeling using the SVP approximation method
Evaluation of radiative accelerations is crucial for computing element segregation in stars. Radiative acceleration is often the leading component in atomic diffusion processes, which causes inhomogeneous abundance distribution of elements throughout stellar interiors and atmospheres.
This physical process is especially important in stellar radiative zones, where turbulence and convection do not take place, making accurate calculations essential for accurate modelling of stellar evolution.
The SVP approximation (a semi-analytic parametric method) provides a numerically efficient approach to calculating radiative accelerations for a wide range of chemical elements and main-sequence stars. This method only applies to stellar interiors.
Atomic Diffusion in Stars
G. Michaud, G. Alecian & J. Richer
(2015, Springer International Publishing)
A comprehensive guide to the physical principles underlying atomic diffusion and radiative acceleration calculations and their applications in stellar evolution and modelling stars (including their atmospheres).
The SVP approximation is valid for trace elements in optically thick layers (stellar interiors) and stars with masses larger than 1 solar mass. It provides accurate results with significantly reduced computational requirements compared to detailed explicit calculations.
Understand how elements migrate within stellar atmospheres and interiors due to competing radiative and gravitational forces.
Learn more →Explore the physics of how radiation net flux accelerates atoms and ions in stars.
Learn more →Deep dive into the mathematical framework and assumptions behind the SVP approximation methodology.
Learn more →Download datasets, calculation codes, and reference materials for implementing the SVP approximation in your research.
Have questions about the SVP approximation or need technical support? Please contact one of the project leads.
LUX, Observatoire de Paris (Meudon)
Address:
5, place Jules Janssen
92190 Meudon, FRANCE
Phone: +33 1 45 07 74 20
Email:
georges.alecian@obspm.fr
Département de physique et d'astronomie, Université de Moncton
Address:
Moncton, N.-B., E1A 3E9
Canada
Phone: (506) 858-4301
Fax: (506) 858-4541