STAREVOL

STAREVOL
Name	STAREVOL
Developer	unknown
Released	1990s
Programming language	Fortran
Operating system	Unix-like
Genre	Stellar evolution code
License	Proprietary / academic

STAREVOL is a computational stellar evolution code used to model the structure, nucleosynthesis, and angular momentum evolution of stars across a range of masses and compositions. The code has been applied in studies of low-mass stars, intermediate-mass stars, brown dwarfs, and population synthesis, interfacing with observational programs and theoretical frameworks from projects such as Kepler (spacecraft), Gaia (spacecraft), Hubble Space Telescope, Very Large Telescope, and Atacama Large Millimeter Array. STAREVOL integrates microphysics, rotation, and mixing processes to support comparisons with datasets from surveys like APOGEE, GALAH, SDSS and missions such as TESS and CoRoT.

Overview

STAREVOL is oriented toward evolutionary tracks, isochrones, and internal transport processes for stellar models used in studies of nucleosynthesis, surface abundance patterns, and angular momentum. The code outputs predictions used by groups at institutions such as Observatoire de Paris, CEA Saclay, CNRS, Max Planck Society, and University of Cambridge for comparison with spectroscopic analyses from teams associated with ESO, Keck Observatory, Subaru Telescope, and Gemini Observatory. Its user community overlaps with collaborations at Institut d'Astrophysique de Paris, Laboratoire d'Astrophysique de Bordeaux, University of Geneva, and survey consortia like LAMOST and RAVE (survey).

History and Development

STAREVOL originated in the early development era of modern stellar codes alongside projects such as MESA (software), CESAM, GARSTEC, FRANEC, and ATON (code). Initial work involved researchers affiliated with institutions including Université Joseph Fourier, Observatoire de Lyon, and Institut d'Astrophysique de Paris. Over successive decades STAREVOL incorporated physics advances reflected in comparisons with models from Iben (astronomer), Schwarzschild (astronomer), Kippenhahn, and work by groups at Princeton University, Harvard–Smithsonian Center for Astrophysics, and University of California, Santa Cruz. Development tracked improvements in opacities from projects such as OPAL and OP (Opacity Project), and reaction rates from NACRE and JINA (Joint Institute for Nuclear Astrophysics).

Physical and Computational Model

The computational framework of STAREVOL solves 1D stellar structure and transport equations using finite-difference methods similar to approaches in Eggleton (astrophysicist) codes and successor tools used at Los Alamos National Laboratory and Lawrence Livermore National Laboratory. The model includes equations for mass conservation, hydrostatic equilibrium, energy transport, and composition evolution coupled to angular momentum transport inspired by the formalism of Zahn (astrophysicist), Maeder (astrophysicist), and Mestel (astrophysicist). Numerical implementation interfaces with opacity tables from OPAL and AESOPUS, equation-of-state treatments related to Saumon (physicist) work for brown dwarfs, and nuclear networks comparable to those employed by REACLIB and JINA REACLIB.

Input Physics and Microphysics

STAREVOL employs microphysics modules for radiative opacities, conductive opacities, and molecular opacities drawn from databases and projects like OPAL, OP (Opacity Project), AESOPUS, Ferguson (opacities), and Kurucz (astrophysicist). Nuclear reaction networks use compilations from NACRE, JINA (Joint Institute for Nuclear Astrophysics), and rates benchmarked against work by Angulo (physicist) and Descouvemont (physicist). Convection is treated with mixing-length theory following prescriptions akin to Böhm-Vitense, with optional overshoot and semiconvection modules comparable to parameterizations used by Herwig (astrophysicist) and Renzini (astronomer). Rotation-induced mixing and magnetic braking adopt formalisms inspired by Zahn (astrophysicist), Mestel (astrophysicist), and empirical calibrations from open-cluster studies such as Hyades, Pleiades, and Praesepe.

Applications and Scientific Results

STAREVOL models have been used to interpret surface abundances in giants and subgiants observed in surveys like APOGEE, GALAH, and Gaia-ESO Survey, and to study lithium depletion patterns seen in datasets from Kepler (spacecraft), TESS, and ground-based spectrographs on VLT and Keck Observatory. The code contributed to investigations of angular momentum evolution relevant to research by groups at University of Geneva, University of Exeter, and Institut d'Astrophysique de Paris on gyrochronology in clusters including M67 and NGC 6819. Nucleosynthesis outputs have informed studies of Galactic chemical evolution with teams associated with Princeton University, University of Cambridge, Harvard University, and Max Planck Institute for Astronomy.

Validation and Benchmarking

Validation efforts for STAREVOL include comparisons with independent codes such as MESA (software), GARSTEC, FRANEC, and CESAM and with observational constraints from asteroseismology missions Kepler (spacecraft), CoRoT, and TESS. Benchmarks test predictions for main-sequence lifetimes, red-giant branch loci, and core He-burning phases against isochrone sets from Padova group, BaSTI, and PARSEC models, and against cluster color–magnitude diagrams for Hyades, Pleiades, and Praesepe.

Availability and Usage

STAREVOL is distributed primarily through academic collaborations and upon request to development teams at institutions such as Observatoire de Paris and Laboratoire d'Astrophysique de Bordeaux; usage policies resemble those of codes like MESA (software) and GARSTEC, with citation expectations aligned with publications from the development group. Users typically run the code on Unix-like clusters at facilities including GENCI, CEA, IN2P3 and university high-performance computing centers such as CC-IN2P3 and National Energy Research Scientific Computing Center.

Category:Stellar evolution codes