Proper Motion Tangential Velocity Calculator
Total tangent-plane proper-motion speed with AU/Julian-year coefficient; no radial component. Model only, not an ephemeris, measured stellar identity or observational guarantee.
Description
Proper motion and distance together determine a tangential speed under consistent units.
Proper motion and distance together determine a tangential speed under consistent units.1
This transverse component does not include radial velocity. Use Proper Motion Tangential Velocity Calculator to evaluate the supplied inputs under the model explained below.
When to use Proper Motion Tangential Velocity Calculator
Use Proper Motion Tangential Velocity Calculator to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.
How to use Proper Motion Tangential Velocity Calculator and understand its results
- Establish the units, measurement scope and model assumptions before entering values.
- Enter Proper motion arcsec per julian year, Distance parsecs using the field table and validation rules below, then run the tool.
- Read Tangential velocity km per second; interpret the units, signs, ordering and unknown-value placeholders described below.
- Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| properMotionArcsecPerJulianYear | Proper motion arcsec per julian year | number | Required; constraints below |
| distanceParsecs | Distance parsecs | number | Required; constraints below |
Enter nonnegative proper-motion magnitude in arcsec per Julian year and positive distance in pc. Return 4.740470463533486×motion×distance in km/s. Zero motion returns zero; no parallax inversion or radial component occurs.
tangentialKmPerSecond=4.740470463533486×motionArcsecPerJulianYear×distancePc Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| tangentialVelocityKmPerSecond | Tangential velocity km per second | number |
{
"input": {
"properMotionArcsecPerJulianYear": 1,
"distanceParsecs": 10
},
"output": {
"tangentialVelocityKmPerSecond": 47.40470463533485
}
}Limitations and assumptions
This transverse component does not include radial velocity. Apply the exact scope and assumptions explained above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.
Alternative or Complementary methods
Use Proper Motion from Tangential Velocity Inverse Converter for a related task: Tangential speed and distance can be inverted to obtain angular proper motion.
Use High Proper Motion Star Threshold 180 mas/yr Flag Checker for a related task: A high-proper-motion flag compares a measured magnitude with a chosen catalog threshold.
References
Similar or alternative tools
- Proper Motion from Tangential Velocity Inverse Converter
Tangential speed and distance can be inverted to obtain angular proper motion.
- High Proper Motion Star Threshold 180 mas/yr Flag Checker
A high-proper-motion flag compares a measured magnitude with a chosen catalog threshold.