The Southern Variable Star Search aims to get people across Australia taking systematic images of the night sky and analysing them to discover new Variable Stars.
What is a Variable Star?
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either:
Intrinsic variables, whose luminosity actually changes; for example, because the star periodically swells and shrinks.
Extrinsic variables, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes eclipses it.
Why look for them in the Southern Sky?
The latest edition of the General Catalogue of Variable Stars (2008) lists more than 46,000 variable stars in the Milky Way, as well as 10,000 in other galaxies, and over 10,000 ‘suspected’ variables. Most of these are in the northern sky as there are more observers in the northern hemisphere to find them! That should mean that there is a treasure-trove of variable stars waiting to be discovered in the Southern Sky.
…but I’m not an Astrophysicist!
Neither am I! This guide provides step-by-step instructions on selecting a region to explore, taking images and how to analyse them. Teams then work together to cross-check results and submit our discoveries.