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.

What is the baseline for determining the magnitude scale of celestial objects? Why do brighter objects have negative numbers? Dean Treadway Knoxville, Tennessee The first observer to catalog ...

The Cocoon Nebula, an emission nebula spanning 12 arcminutes (1/5 degree) in the constellation Cygnus, is approximately 4,000 light-years distant and possesses a diameter of 15 light-years. This ...

"We thought clouds would hide life from us, but surprisingly, they could help us find life." Astronomers usually don't like clouds. After all, clouds obscure their view of the cosmos. But dense cloud ...