Oort constants
E471607
The Oort constants are two parameters in galactic astronomy that quantify the local rotational properties of the Milky Way near the Sun, particularly its differential rotation.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Oort constants canonical | 4 |
| Oort constant A | 1 |
| Oort constant B | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4814329 — 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: Oort constants Context triple: [Jan Oort, knownFor, Oort constants]
-
A.
Keplerian orbital elements
Keplerian orbital elements are a set of parameters that uniquely describe the size, shape, and orientation of an orbit and the position of an orbiting body along that path.
-
B.
Titius–Bode law
The Titius–Bode law is an 18th-century empirical rule that approximates the distances of planets from the Sun using a simple numerical sequence, historically noted for roughly predicting the positions of several known planets and the asteroid belt.
-
C.
Oort cloud
The Oort cloud is a distant, spherical shell of icy bodies surrounding the Solar System, thought to be the source of many long-period comets.
-
D.
Gauss’s planetary equations
Gauss’s planetary equations are a set of differential equations in celestial mechanics that describe how a planet’s orbital elements change over time under the influence of perturbing forces.
-
E.
Orbit
Orbit is a publishing imprint best known for releasing science fiction and fantasy books.
- 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: Oort constants Target entity description: The Oort constants are two parameters in galactic astronomy that quantify the local rotational properties of the Milky Way near the Sun, particularly its differential rotation.
-
A.
Keplerian orbital elements
Keplerian orbital elements are a set of parameters that uniquely describe the size, shape, and orientation of an orbit and the position of an orbiting body along that path.
-
B.
Titius–Bode law
The Titius–Bode law is an 18th-century empirical rule that approximates the distances of planets from the Sun using a simple numerical sequence, historically noted for roughly predicting the positions of several known planets and the asteroid belt.
-
C.
Oort cloud
The Oort cloud is a distant, spherical shell of icy bodies surrounding the Solar System, thought to be the source of many long-period comets.
-
D.
Gauss’s planetary equations
Gauss’s planetary equations are a set of differential equations in celestial mechanics that describe how a planet’s orbital elements change over time under the influence of perturbing forces.
-
E.
Orbit
Orbit is a publishing imprint best known for releasing science fiction and fantasy books.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
Oort constant
ⓘ
Oort constant ⓘ astronomical constant set ⓘ galactic dynamics parameter ⓘ |
| appliesTo |
solar neighborhood
ⓘ
thin disk stars near the Sun ⓘ |
| assumes |
approximate axisymmetry of the Galactic disk
ⓘ
small region around the Sun ⓘ |
| category |
Milky Way structure
ⓘ
linked to:
Milky Way
astrophysical constants ⓘ |
| dependsOn | Galactocentric distance of the Sun ⓘ |
| expressedIn | kilometers per second per kiloparsec ⓘ |
| field |
astrophysics
ⓘ
galactic dynamics ⓘ |
| frameOfReference | local standard of rest ⓘ |
| hasMember |
Oort constant A
ⓘ
linked to:
Oort constants
Oort constant B ⓘ
linked to:
Oort constants
|
| introducedBy | Jan Oort ⓘ |
| mathematicallyRelatedTo | derivative of angular rotation speed with respect to Galactocentric radius ⓘ |
| namedAfter | Jan Oort ⓘ |
| quantifies |
local shear of galactic rotation
ⓘ
local vorticity of galactic rotation ⓘ |
| quantify |
differential rotation near the Sun
ⓘ
local rotational properties of the Milky Way ⓘ |
| relatedTo |
angular velocity of galactic rotation
ⓘ
circular velocity of the Milky Way ⓘ epicyclic approximation ⓘ epicyclic frequency ⓘ galactic rotation curve ⓘ shear of galactic rotation ⓘ vorticity of galactic rotation ⓘ |
| sign |
negative in the Milky Way near the Sun
ⓘ
positive in the Milky Way near the Sun ⓘ |
| symbolForMember |
A
ⓘ
B ⓘ |
| typicalValueApprox |
-12 km/s/kpc
ⓘ
15 km/s/kpc ⓘ |
| usedFor |
constraining the local shape of the Milky Way rotation curve
ⓘ
converting observed stellar proper motions to galactic rotation parameters ⓘ determining local galactic shear ⓘ determining local galactic vorticity ⓘ estimating Milky Way mass distribution near the Sun ⓘ modeling stellar motions in the solar neighborhood ⓘ testing axisymmetric models of the Milky Way ⓘ |
| usedIn |
Milky Way kinematics
ⓘ
galactic astronomy ⓘ galactic rotation studies ⓘ |
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: Oort constants Description of subject: The Oort constants are two parameters in galactic astronomy that quantify the local rotational properties of the Milky Way near the Sun, particularly its differential rotation.
Referenced by (6)
Full triples — surface form annotated when it differs from this entity's canonical label.