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

A Cepheid variable is a variable star that pulsates radially, varying in both diameter and temperature causing changes in brightness with...

The Greco-Roman Ptolemy listed 48 constellations after 150 AD. These were: Andromeda Ara Aries Aquarius Aquila Argo Auriga Boötes Cancer...

A star is a luminous ball of gas (mostly hydrogen and helium) held together by its own gravity. Nuclear fusion reactions at its core...

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

Yes due to precession. About 12,000 BC Vega was the North Star, lying approximately at the north celestial pole, not Polaris, and in...

An asterism is a small pattern or collection of stars that are not constellations, although they are often parts of a constellation: eg....

The sky is divided into 88 sections, known as constellations, which astronomers use to locate and name celestial objects. Most of the...

This is outlined by three stars: Vega, Deneb & Altair. The asterism 'The Northern Cross' (in the constellation Cygnus) is often used to...

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