[gleeaikin]

I was surprised to be told recently on a science program that most of the planets being discovered are circling dwarf suns with only a fraction the power of our sun. Thus they have to be much closer to their sun in order to have life permitting temperatures.

[samtheman]

I was surprised to be told recently on a science program that most of the planets being discovered are circling dwarf suns with only a fraction the power of our sun. Thus they have to be much closer to their sun in order to have life permitting temperatures.

20 out of the 30 stars nearest to Earth are red dwarfs

And you're right, planets will have to be close in.
When a planet orbits a star this closely, the gravitational pull of the star may cause the planet to become tidally locked with the same side always facing the star (similar to the Moon's fixed gaze on the Earth)..