Planet Elongation Morning/Evening Classifier
Signed east-of-Sun elongation convention: east evening, west morning; local altitude, twilight and observability not inferred. Model only, not an ephemeris, measured stellar identity or observational guarantee.
Description
East or west elongation gives a geometric side relative to the Sun.
East or west elongation gives a geometric side relative to the Sun.1
Calling that side morning or evening does not establish actual visibility at a location. Use Planet Elongation Morning/Evening Classifier to evaluate the supplied inputs under the model explained below.
When to use Planet Elongation Morning/Evening Classifier
Use Planet Elongation Morning/Evening Classifier to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.
How to use Planet Elongation Morning/Evening Classifier and understand its results
- Establish the units, measurement scope and model assumptions before entering values.
- Enter Oriented east elongation degrees using the field table and validation rules below, then run the tool.
- Read Geometric visibility side, Absolute elongation degrees; 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 |
|---|---|---|---|
| orientedEastElongationDegrees | Oriented east elongation degrees | number | Required; constraints below |
Enter finite east-positive elongation in degrees. Wrap (elongation+180) modulo 360 then subtract 180, producing [−180,180). Exact zero returns conjunction; exact absolute 180 returns opposition; positive returns evening and negative morning. Also return absolute elongation. No ephemeris, horizon, latitude or visibility assessment occurs.
oriented=wrap360(input+180)−180; side=zero ? conjunction : abs180 ? opposition : positive ? evening : morning Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| geometricVisibilitySide | Geometric visibility side | string |
| absoluteElongationDegrees | Absolute elongation degrees | number |
{
"input": {
"orientedEastElongationDegrees": 30
},
"output": {
"geometricVisibilitySide": "evening",
"absoluteElongationDegrees": 30
}
}Limitations and assumptions
Calling that side morning or evening does not establish actual visibility at a location. 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 Saros Cycle Eclipse Repeat Years for a related task: A repeat cycle can be represented by a number of matched synodic months.
Use Moonrise Delay Minutes Per Day for a related task: Successive moonrise timestamps can be compared with one ordinary solar day.
References
Similar or alternative tools
- Saros Cycle Eclipse Repeat Years
A repeat cycle can be represented by a number of matched synodic months.
- Moonrise Delay Minutes Per Day
Successive moonrise timestamps can be compared with one ordinary solar day.