Combined Binary Star Magnitude Calculator
Stable additive same-passband unresolved binary magnitude; no magnitude arithmetic average. Model only, not an ephemeris, measured stellar identity or observational guarantee.
Description
Combined magnitude follows from adding fluxes rather than averaging magnitudes.
Combined magnitude follows from adding fluxes rather than averaging magnitudes.1
The two inputs must share a band and magnitude zero point. Use Combined Binary Star Magnitude Calculator to evaluate the supplied inputs under the model explained below.
When to use Combined Binary Star Magnitude Calculator
Use Combined Binary Star Magnitude 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 Combined Binary Star Magnitude Calculator and understand its results
- Establish the units, measurement scope and model assumptions before entering values.
- Enter First magnitude, Second magnitude using the field table and validation rules below, then run the tool.
- Read Combined magnitude; 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 |
|---|---|---|---|
| firstMagnitude | First magnitude | number | Required; constraints below |
| secondMagnitude | Second magnitude | number | Required; constraints below |
Enter finite magnitudes sharing a band and zero point. Set m=min(first,second) and compute m−2.5log10(1+10^(−0.4×abs(first−second))). This stable flux sum returns a brighter combined magnitude. No variability, band conversion or extinction correction occurs.
combinedMagnitude=minMagnitude−2.5log10(1+10^(−0.4×magnitudeDifference)) Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| combinedMagnitude | Combined magnitude | number |
{
"input": {
"firstMagnitude": 5,
"secondMagnitude": 5
},
"output": {
"combinedMagnitude": 4.247425010840047
}
}Limitations and assumptions
The two inputs must share a band and magnitude zero point. 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 Magnitude Flux Ratio Calculator for a related task: Astronomical magnitudes express logarithmic brightness differences.
Use Atmospheric Extinction mag/Airmass for a related task: Extinction can be compared across airmasses with a band-specific coefficient.
References
Similar or alternative tools
- Magnitude Flux Ratio Calculator
Astronomical magnitudes express logarithmic brightness differences.
- Atmospheric Extinction mag/Airmass
Extinction can be compared across airmasses with a band-specific coefficient.