Kramers opacity law
E415081
Kramers opacity law is a fundamental relation in astrophysics that describes how the opacity of stellar material depends on its density and temperature, crucial for modeling energy transport inside stars.
All labels observed (4)
| Label | Occurrences |
|---|---|
| Kramers opacity law canonical | 3 |
| Kramers law | 1 |
| Kramers opacity coefficient | 1 |
| Kramers opacity law in astrophysics | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4142000 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Kramers opacity law Context triple: [Hendrik Anthony Kramers, notableWork, Kramers opacity law]
-
A.
Rosseland mean opacity
Rosseland mean opacity is an average measure of a material’s opacity weighted toward frequencies where radiation is most effectively transported, widely used in stellar and astrophysical radiative transfer calculations.
-
B.
Klein–Nishina formula
The Klein–Nishina formula is a fundamental result in quantum electrodynamics that gives the differential cross section for Compton scattering of photons by free electrons, incorporating relativistic and quantum effects.
-
C.
Saha ionization equation
The Saha ionization equation is a fundamental formula in astrophysics and plasma physics that relates the ionization state of a gas in thermal equilibrium to its temperature and pressure, crucial for understanding stellar atmospheres and spectra.
-
D.
Kirchhoff's three laws of spectroscopy
Kirchhoff's three laws of spectroscopy are foundational principles in physics that explain how continuous, emission, and absorption spectra arise from interactions between matter and radiation.
-
E.
Kirchhoff's law of thermal radiation
Kirchhoff's law of thermal radiation is a fundamental principle in thermodynamics stating that, for a body in thermal equilibrium, its emissivity equals its absorptivity at each wavelength.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Kramers opacity law Target entity description: Kramers opacity law is a fundamental relation in astrophysics that describes how the opacity of stellar material depends on its density and temperature, crucial for modeling energy transport inside stars.
-
A.
Rosseland mean opacity
Rosseland mean opacity is an average measure of a material’s opacity weighted toward frequencies where radiation is most effectively transported, widely used in stellar and astrophysical radiative transfer calculations.
-
B.
Klein–Nishina formula
The Klein–Nishina formula is a fundamental result in quantum electrodynamics that gives the differential cross section for Compton scattering of photons by free electrons, incorporating relativistic and quantum effects.
-
C.
Saha ionization equation
The Saha ionization equation is a fundamental formula in astrophysics and plasma physics that relates the ionization state of a gas in thermal equilibrium to its temperature and pressure, crucial for understanding stellar atmospheres and spectra.
-
D.
Kirchhoff's three laws of spectroscopy
Kirchhoff's three laws of spectroscopy are foundational principles in physics that explain how continuous, emission, and absorption spectra arise from interactions between matter and radiation.
-
E.
Kirchhoff's law of thermal radiation
Kirchhoff's law of thermal radiation is a fundamental principle in thermodynamics stating that, for a body in thermal equilibrium, its emissivity equals its absorptivity at each wavelength.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
astrophysical relation
ⓘ
physical law ⓘ |
| appliesTo |
ionized gases
ⓘ
stellar envelopes ⓘ stellar interiors ⓘ |
| approximationType | power-law opacity approximation ⓘ |
| assumes |
bound-free and free-free absorption dominate
ⓘ
partially ionized plasma ⓘ |
| category |
radiative transfer
ⓘ
stellar physics ⓘ |
| connectedTo |
hydrostatic equilibrium in stars
ⓘ
mass–luminosity relation for stars ⓘ |
| dependsOn |
chemical composition of stellar material
ⓘ
ionization state of gas ⓘ |
| describes | dependence of opacity on density and temperature in stellar material ⓘ |
| dimensionOf | opacity per unit mass ⓘ |
| excludesProcess |
electron scattering dominance
ⓘ
molecular opacity dominance ⓘ |
| field |
astrophysics
ⓘ
stellar astrophysics ⓘ |
| hasLimitation |
breaks down at very high temperatures where electron scattering dominates
ⓘ
inaccurate in cool stellar atmospheres with strong molecular opacities ⓘ neglects detailed line opacities ⓘ |
| historicalPeriod | early 20th century ⓘ |
| includesProcess |
bound-free absorption
ⓘ
free-free absorption ⓘ |
| influenced |
development of stellar structure theory
ⓘ
early models of main-sequence stars ⓘ |
| involvesConstant |
Kramers opacity law
self-linksurface differs
ⓘ
surface form:
Kramers opacity coefficient
|
| isApproximationOf |
frequency-averaged opacity
ⓘ
more detailed opacity tables ⓘ |
| mathematicalForm | κ ∝ ρ T^(-7/2) ⓘ |
| namedAfter | Hendrik Anthony Kramers ⓘ |
| relatedTo |
Rosseland mean opacity
ⓘ
radiative diffusion equation ⓘ |
| relatesQuantity |
mass density
ⓘ
opacity ⓘ temperature ⓘ |
| usedAs | pedagogical tool in stellar astrophysics courses ⓘ |
| usedFor |
modeling radiative energy transport in stars
ⓘ
stellar evolution models ⓘ stellar structure calculations ⓘ |
| usedIn |
Eddington standard model of stars
ⓘ
surface form:
Eddington standard model of stellar structure
analytic estimates of stellar lifetime ⓘ analytic estimates of stellar luminosity ⓘ polytropic stellar models ⓘ |
| validWhen |
gas is not completely degenerate
ⓘ
photon energies are below ionization edges of dominant ions ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Kramers opacity law Description of subject: Kramers opacity law is a fundamental relation in astrophysics that describes how the opacity of stellar material depends on its density and temperature, crucial for modeling energy transport inside stars.
Referenced by (6)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
Hendrik Anthony Kramers
this entity surface form:
Kramers opacity law in astrophysics
this entity surface form:
Kramers opacity coefficient
this entity surface form:
Kramers law