Star Brightness Ratio Calculator
The stellar magnitude scale is backward and logarithmic: smaller numbers mean brighter stars, and every step of one magnitude is a fixed brightness ratio of about two point five one two, the fifth root of one hundred. That means a five magnitude gap is exactly one hundred times in brightness. This calculator turns any magnitude difference between two stars into a plain brightness ratio, so you can say how many times brighter one object is than another. Enter two magnitudes or a single difference and it reports the factor both ways. It is handy for comparing planets, variable stars or the faintest object your eye or scope can reach. Everything is computed locally in your browser.
How to use Star Brightness Ratio Calculator
- Enter the magnitude of the first star.
- Enter the magnitude of the second star.
- Read how many times brighter one is from the Pogson ratio.
Frequently asked questions
How does a magnitude difference become a brightness ratio?
Each step of one magnitude is a factor of about 2.512 in brightness, so the ratio is 2.512 raised to the magnitude difference between the two stars.
Why is the fainter star the larger number?
The magnitude scale runs backwards, so a bigger magnitude means a dimmer star; a difference of 5 magnitudes is exactly a 100 times brightness ratio.
What is the Pogson ratio?
It is the fixed base 2.512, chosen so that five magnitudes equal a hundredfold brightness change, which the calculator uses to convert any magnitude gap.
What is Star Brightness Ratio Calculator?
The stellar magnitude scale is backward and logarithmic: smaller numbers mean brighter stars, and every step of one magnitude is a fixed brightness ratio of about two point five one two, the fifth root of one hundred. That means a five magnitude gap is exactly one hundred times in brightness.
Is Star Brightness Ratio Calculator free to use?
Yes. Star Brightness Ratio Calculator is completely free, with no sign-up and no usage limits.
Does Star Brightness Ratio Calculator work in a web browser?
Yes. Star Brightness Ratio Calculator runs in any modern web browser. There is nothing to download or install.
Is my data private with Star Brightness Ratio Calculator?
Yes. Star Brightness Ratio Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.
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