EOS interpolation, atmosphere matching and model domains
Research context
research method · conditional · As of 2026-10-10
A stellar or planetary EOS can blend differently valid microscopic models.
Key knowledge
A stellar or planetary EOS can blend differently valid microscopic models. Thermodynamic derivatives must remain consistent across blends; opacity and atmosphere tables use their own composition and temperature ranges. An extrapolated fit is a separate assumption.
Values and equations
T^4=(3/4) Teff^4(τ+2/3); dP/dτ=g/κ
- T,Teff
- Temperature and effective temperature K
- τ
- Inward optical depth 1
- P
- Hydrostatic pressure Pa
- g
- Approximately constant surface gravity m s^-2
- κ
- Mass opacity m^2 kg^-1
Conditions and scope
- MESA's named EOS domains and cgs table conventions must be retained when converting units.
- For a grey plane-parallel radiative atmosphere the Eddington relation is conditional, and a fitted surface boundary need not describe an irradiated planet.
- Grey, radiative, plane-parallel Eddington atmosphere with negligible external illumination; hydrostatic pressure relation uses consistent total opacity/pressure support.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
MESA equation-of-state module: Blended EOS domains, thermodynamic derivatives and composition assumptions (selected source body inspected). MESA T(tau) atmospheres: Grey relation, pressure integration, opacity options and surface matching (selected source body inspected).
2026-10-10 · Bounded source check of the recorded statement and conditions. This does not certify a unique physical model, reproduce the cited study or replace independent branch review.
Entry details
Permanent link to this entry ↗- Record identity
- research-earth-stellar-eos-opacity
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference