Can someone explain to me how this planet can be 10,000,000 years old? Isn't that formation far too new for a star system that close? I would have expected such formation to be inside a nebula near the core of the galaxy.
http://en.wikipedia.org/wiki/Thin_disk
Star ages can be estimated by their composition (older stars contain more helium), color (bluer stars live far shorter than redder stars), brightness for their given color (older stars burn brighter), activity (younger stars are more active, they flare more) and if they contain protoplanetary disks (a feature of very young stars).
Astronomers also use the HR diagram: http://en.wikipedia.org/wiki/Hertzsprung%E2%80%93Russell_dia...
Having a good measure of distance is important and there are various ways to determine that: http://en.wikipedia.org/wiki/Cosmic_distance_ladder