The initial magnitude scale was established by Greek astronomer Hipparchus around 135 B.C.E., categorizing approximately 850 stars into six ranges from 1st (brightest) to 6th (faintest) magnitude.

Stars come in all colors and sizes. But our eyes limit us to seeing very few of those colors. And the range of apparent magnitudes of stars we can see with our naked eye is also rather limited.

The first observer to catalog differences in star brightnesses was Greek astronomer Hipparchus. He created a catalog around 135 b.c. of roughly 850 stars divided into six ranges. He called the ...