Barycentric Dynamical Time
E497212
Barycentric Dynamical Time is a relativistic time scale used in celestial mechanics and ephemerides, defined for an observer at the solar system’s barycenter to accurately model planetary and spacecraft motions.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Barycentric Dynamical Time canonical | 5 |
| Barycentric Coordinate Time | 4 |
How this entity was disambiguated
This entity first appeared as the object of triple T5150756 — 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: Barycentric Dynamical Time Context triple: [Terrestrial Time, basisOf, Barycentric Dynamical Time]
-
A.
Terrestrial Time
Terrestrial Time is a modern astronomical time standard used for precise calculations of planetary motion and ephemerides, defined in relation to atomic time rather than Earth's rotation.
-
B.
International Celestial Reference System
The International Celestial Reference System is the standard, high-precision coordinate framework used in astronomy and geodesy to define positions of celestial objects relative to distant quasars.
-
C.
IERS ICRS Centre
The IERS ICRS Centre is the component of the International Earth Rotation and Reference Systems Service responsible for realizing, maintaining, and providing access to the International Celestial Reference System used for precise astronomical and geodetic measurements.
-
D.
International Atomic Time
International Atomic Time is a high-precision time standard based on the combined output of atomic clocks worldwide, serving as the fundamental reference for modern civil and scientific timekeeping.
-
E.
Coordinated Universal Time
Coordinated Universal Time (UTC) is the primary global time standard by which the world regulates clocks and time, serving as the basis for most civil time zones.
- 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: Barycentric Dynamical Time Target entity description: Barycentric Dynamical Time is a relativistic time scale used in celestial mechanics and ephemerides, defined for an observer at the solar system’s barycenter to accurately model planetary and spacecraft motions.
-
A.
Terrestrial Time
Terrestrial Time is a modern astronomical time standard used for precise calculations of planetary motion and ephemerides, defined in relation to atomic time rather than Earth's rotation.
-
B.
International Celestial Reference System
The International Celestial Reference System is the standard, high-precision coordinate framework used in astronomy and geodesy to define positions of celestial objects relative to distant quasars.
-
C.
IERS ICRS Centre
The IERS ICRS Centre is the component of the International Earth Rotation and Reference Systems Service responsible for realizing, maintaining, and providing access to the International Celestial Reference System used for precise astronomical and geodetic measurements.
-
D.
International Atomic Time
International Atomic Time is a high-precision time standard based on the combined output of atomic clocks worldwide, serving as the fundamental reference for modern civil and scientific timekeeping.
-
E.
Coordinated Universal Time
Coordinated Universal Time (UTC) is the primary global time standard by which the world regulates clocks and time, serving as the basis for most civil time zones.
- F. None of above. chosen
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical time standard
ⓘ
coordinate time scale ⓘ relativistic time scale ⓘ |
| abbreviation | TDB ⓘ |
| accountsFor |
gravitational time dilation
ⓘ
relativistic effects in the solar system ⓘ special relativistic time dilation ⓘ |
| category |
Celestial mechanics
ⓘ
Relativity in astronomy ⓘ Time in astronomy ⓘ |
| closelyMatches | Terrestrial Time ⓘ |
| coordinateOrigin | solar system barycenter ⓘ |
| definedBy | International Astronomical Union ⓘ |
| definedForObserverAt | solar system barycenter ⓘ |
| definedIn | IAU 1976 system of astronomical constants ⓘ |
| definedOnGeoid | no ⓘ |
| differenceFrom | Terrestrial Time is periodic and small ⓘ |
| domain | solar system dynamics ⓘ |
| epochReference | Julian Date ⓘ |
| hasNature | theoretical coordinate time rather than directly observable time ⓘ |
| maintainedBy |
Bureau des Longitudes
ⓘ
Jet Propulsion Laboratory ⓘ |
| measuredIn | SI seconds ⓘ |
| referenceFrame | barycentric celestial reference system ⓘ |
| refinedBy | IAU 2006 resolutions ⓘ |
| relatedTo |
Barycentric Coordinate Time
ⓘ
linked to:
Barycentric Dynamical Time
Terrestrial Time via relativistic transformation ⓘ |
| replacedInPracticeBy | Barycentric Coordinate Time for theoretical work ⓘ |
| successorOf | Ephemeris Time ⓘ |
| symbol | TDB ⓘ |
| timeArgumentOf |
planetary motion models
ⓘ
solar system dynamical theories ⓘ spacecraft trajectory models ⓘ |
| typicalOffsetMagnitude | on the order of milliseconds relative to Terrestrial Time ⓘ |
| usedAsTimeArgumentIn |
INPOP ephemerides
ⓘ
JPL planetary ephemerides ⓘ
linked to:
JPL HORIZONS system
|
| usedFor |
accurate modeling of planetary motions
ⓘ
accurate modeling of spacecraft motions ⓘ timing of observations of solar system bodies ⓘ |
| usedIn |
celestial mechanics
ⓘ
high‑precision astrometry ⓘ planetary ephemerides ⓘ solar system ephemerides ⓘ spacecraft navigation ⓘ |
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: Barycentric Dynamical Time Description of subject: Barycentric Dynamical Time is a relativistic time scale used in celestial mechanics and ephemerides, defined for an observer at the solar system’s barycenter to accurately model planetary and spacecraft motions.
Referenced by (9)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject linked to:
TT
linked to: Barycentric Dynamical Time
linked to: Barycentric Dynamical Time
linked to: Barycentric Dynamical Time
linked to: Barycentric Dynamical Time