A variable star's apparent brightness changes over time as seen from Earth. There are 2 basic types: intrinsic variables whose luminosity...

Stellar classification is usually based on two classification schemes, based on the star's surface temperature (the Harvard system), and...

This is a way of measuring the quality (brightness) of the night sky for a given location and it was created and published in 2001 by...

The brightness of stars appears to be different, because they give out different amounts of light and they lie at vastly different...