"Smaller, hotter, but in the habitable zone of it's star. Relpek 681f orbits a hot yellow star but far enough out to not be cooked by it. Yellow stars are so hot that they would turn our planet into a barren, semi-molten wasteland at the same distance.

Scientists have noted that the atmosphere of Relpek 681f would have to be very thin in order for it to maintain cool enough temperatures, but it's well known that plant life would probably have an easier time dealing with it's solar radiation output..."