Planetary equilibrium temperature model
A spherical planet intercepts stellar power over its projected disk and emits thermal power over its surface.
Key knowledge
A spherical planet intercepts stellar power over its projected disk and emits thermal power over its surface. With isotropic stellar luminosity L, Bond albedo A_B, uniform blackbody emission and no internal heat, equilibrium gives T_eq=[(1−A_B)L/(16πσ_SB d²)]¹ᐟ⁴. This is a radiative model temperature, rather than an automatic surface or exobase temperature.
Values and equations
T_eq⁴=(1−A_B)L/(16πσ_SB d²)
- T_eq
- uniform blackbody equilibrium temperature K
- A_B
- Bond reflected-energy fraction 1
- L
- isotropic stellar luminosity W
- d
- planet–star distance m
- σ_SB
- Stefan–Boltzmann constant W m⁻² K⁻⁴
Conditions and scope
- Fixed planet–star distance d much larger than their radii,0≤A_B≤1, transparent intervening space, steady balance and unit thermal emissivity.
- Nonuniform heat redistribution, wavelength-dependent emission, atmosphere and internal energy require a fuller model. For an eccentric orbit, evaluating at one distance does not automatically give a time-averaged temperature.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read the albedo/interception/emission setup and the displayed temperature equation11. Independently equated πR_p²(1−A_B)L/(4πd²) and4πR_p²σ_SB T⁴; corrected the source's malformed projected-area expression and excluded its old numerical planet/exoplanet examples.
2026-10-10 · Independent AI editorial review: All44 exact root-authored compact records, equations/variable units/conditions and140 origin edges accepted after independently reading final6/18 with bounded primary bodies and matching prior38/122 scientific fingerprints unchanged. Exact claim/edge review is distinct from combined inventory scope and separate CLE26 approval; no entire cited books or old-corpus experimental revalidation is asserted. Receipt: cosmos-completion-independent-content-and-inventory-review.1.
Entry details
Permanent link to this entry ↗- Record identity
- uni-cosmos-planetary-radiative-balance
- Revision
- core.1
- Structured reference record
- University core expansion