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THE FEUTEX TOOLKIT

Combined Stellar Magnitude

Combine the apparent brightness of two unresolved stars.

Astronomy workspace● Runs in your browser
01 Your input
02 Your result
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FormulaCombined magnitude = -2.5*log10(10**(-0.4*m1)+10**(-0.4*m2)); Second-to-first flux ratio = 10**(-0.4*(m2-m1))
Sources and model references

Worked example

Inputs

First magnitude
5 mag
Second magnitude
5 mag

Expected results

Combined magnitude
4.247425011 mag
Second-to-first flux ratio
1

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Combine the apparent brightness of two unresolved stars.
  2. Set first magnitude, second magnitude in the indicated units.
  3. Calculate and compare combined magnitude, second-to-first flux ratio.

Try this example

{
  "m1": 5,
  "m2": 5
}

Accuracy and scope

Idealized educational model. Enter measured values in the displayed units; real systems may require additional corrections.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.