orbital period
Let an agent handle orbital periods by body, type of period, calculation and data sources.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent handle orbital periods by body, type of period, calculation and data sources.
The time a body takes to complete one orbit around another, measured as sidereal period (relative to the stars) or synodic period (relative to the Sun as seen from the primary); for Earth around the Sun, about one year.
What it is for: Describing orbits of planets, moons, satellites and stars.
It can be look up orbital periods; compute periods with Kepler third law; distinguish sidereal and synodic periods; plan observations.
Distinguishing features
Time for one orbit
Depends on orbit size and masses
Several definitions
Computed from Kepler laws
What it looks like
Not visible; expressed as time for one orbit.
Physical character
Earth sidereal year: about 365.256 days
low Earth orbit period: about 90 minutes
How it is recognised
Sidereal and synodic periods
Units such as days or years
Satellite periods in minutes
Related models
is a kind of - category
is described by - physics
applies to - bodies
is related to - path
In practice
Families and kinds
sidereal period
synodic period
tropical and anomalistic years
satellite orbital periods
binary star periods
Standards and regulation
IAU astronomical constants
Failure modes and hazards
Mixing sidereal and synodic periods
Unit errors
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Value How long.
Values need definitions.
Body
Which orbit.
Body
Orbiting body.
- Which body and primary are concerned? definition
- What is the orbital period? measurement
Type
Sidereal or synodic.
Type
Period type.
- Is the sidereal or synodic period meant? definition
- Why do they differ? definition
Calculation Kepler third law.
Physics predicts periods.
Kepler
Formula.
Kepler
Kepler third law.
- What period follows from this semi-major axis and mass? measurement
- Which approximations were made? boundary
Units
Conversion.
Units
Units.
- In which units is the period given? definition
- How does it convert? measurement
Data Sources.
Data should be sourced.
Ephemeris
Reference data.
Ephemeris
Reference data.
- Which ephemeris or catalogue gives the value? provenance
- How precise is it? measurement
Satellites
Artificial.
Satellites
Satellite periods.
- What is the satellite orbital period? measurement
- From which tracking data? provenance
Use Applications.
Periods have uses.
Observing
Planning.
Observing
Observation planning.
- When will the body next be well placed for observation? measurement
- How does the synodic period help? definition
Calendars
Years.
Calendars
Calendar years.
- How does the orbital period relate to calendar years? definition
- Why are leap years needed? definition
What the second pass must settle
- Should period types be separate entries?
- How should ephemerides be linked?
- How should satellite data be linked?