Celestia Forums

I know what type of planet could not be tide locked in a K star. The planet would orbit a Brown Dwarf, would have a fast orbit around this and distant to the primary star. The heat radiation of the Brown Dwarf would the planet and the light of the primary star would be added.
I think this is the only way to a planet not be tide locked with the K star type.

Yes; that would work, or even aplanet orbiting a Jupiter class world-
warning! these worlds may have unacceptably harsh radiation belts around them.

But you are perhaps a little pessimistic about the habitable zone of K class stars; Epsilion Eridani, for instance, has a comfort zone of 0.54 A.U.
If you take into account the infra-red fracytion, it will probably be okay to put a planet at about 0.6 A.U., and such a world need not be tidally locked at all.

I heard that Brown Dwarfs can heat planets near them. But my idea is to put the Brown Dwarf at a distance of 1.2 AU. The planet would be heated by the radiation of the Brown Dwarf and also by the geotermic forces. And the primary star would only serve to add light and some radiation.

It would work - in fact, I've already done that for Antares in a scifi game I have. (course, I then blew up Antares... )

Problem with brown dwarfs is that they're only warm enough to support life on any satellites around them for a very brief period of time at the start of their lives. Past an age of about 1.5 billion years, no BD of any mass is going to be warm enough to have a habitable zone around them.

Adam Burrows has written a lot about the evolution of BDs, so if you're scientifically minded you can check the papers there.

He's got a calculator on his website based on some equations in his papers that tells you the temperature, radius, and luminosity of a BD given its mass and age.

Thanks for the calculator, Doctor; it shows that some brown dwarfs have surface gravities of about 30 gee- that makes my Dreamsphere construct almost plausible...