Stellar Equations Of State


Astronomy research
Software instruments
   Stellar equation of states
   EOS with ionization
   EOS for supernovae
   Chemical potentials
   Stellar atmospheres
   Voigt Function
   Jeans escape
   Polytropic stars
   Cold white dwarfs
   Hotter white dwarfs
   Cold neutron stars
   Stellar opacities
   Neutrino energy loss rates
   Ephemeris routines
   Fermi-Dirac functions
   Galactic chemical evolution

   Nuclear reaction networks
   Nuclear statistical equilibrium
   Laminar deflagrations
   CJ detonations
   ZND detonations
   Fitting to conic sections
   Unusual linear algebra
   Derivatives on uneven grids
   Pentadiagonal solver
   Quadratics, Cubics, Quartics
   Supernova light curves
   Exact Riemann solutions
   1D PPM Hydrodynamics
   Verification problems
   Plane - Cube Intersection


   Zingale's software
   Brown's dStar
   GR1D code
   Iliadis' STARLIB database
   Herwig's NuGRID
   Meyer's NetNuc
Bicycle adventures

AAS Journals
2017 MESA Marketplace
2017 MESA Summer School
2017 ASU+EdX AST111x
Teaching materials
Education and Public Outreach

Contact: F.X.Timmes
my one page vitae,
full vitae,
research statement, and
teaching statement.

Before using these instruments, you should glance at the journal papers that describe them. Here then are bzip2 tarballs of six stellar interior equations of state:

helmholtz.tbz nadyozhin.tbz iben.tbz
weaver.tbz arnett.tbz timmes.tbz

The Helmholtz EOS executes the fastest, displays perfect thermodynamic consistency, and has a maximum error of 1e-6. Helmholtz is the stellar EOS of choice in the FLASH software instrument and the backbone of the EOS module in the MESA instrument. The Helmholtz free energy data file spans 10-12 ≤ density (g cm-3) ≤ 1015 and 103 ≤ temperature (K) ≤ 1013. The Nadyozhin EOS is the fastest of the analytic routines, has very good thermodynamic consistency, a maximum error of 1e-5, and is avaliable in FLASH. The Timmes EOS is as slow as molasses during a North Dakota winter, but it computes the non-interacting electron-positron equation of state with no approximations, is exact to machine precision in IEEE double precision arithmetic, has excellent thermodynamic consistency, and serves as the reference point for comparisons to the other EOS routines. The Helmholtz free energy table used by the Helmholtz EOS is calculated from the Timmes EOS.

Pressure differences
Thermodynamic consistency


Please cite the relevant references if you publish a piece of work that use these codes, pieces of these codes, or modified versions of them. Offer co-authorship as appropriate.