This is basically a Encyclopedia for every single Kerban planet. It will help you with size, orbit, interesting things, stats, and basically everything you need to know.
Kerbol (Sun)
Kerbol, or the Kerbol system's star, is the only thing in the game you cannot land on.
Statistics
Heat:3000 - 9000 Farenheit
Oxygen:Yes
Moons:No
Escape Velocity:90,000ish
Landing
Even with "Ignore Temperature" on, anything below -250 will be instantly destroyed no matter how many cheats you have installed.
Orbit
It is definitely possible to orbit Kerbol. However, you'll need several or more heat shields. And solar panels will give you a whole lot of power!