Oh, bleh. I got my Jupiter masses and earth masses mixed up! (1000 earths = 1 Jupiter, 1000 Jupiters = 1 Solar mass)
8 jupiter masses is still basically a massive gas giant though, not a brown dwarf. Minimum mass for a BD is generally accepted to be around 12-13 Jupiter masses. Really that should be a Class IV (or V?) Gas Giant (there are plenty of Class IVs in the game that are more massive than this BD - Class IVs and Vs can either be hot because of proximity to the star or because they are high mass and radiating heat, and the Class IVs I've encountered are often 10-12 Jupiter masses).