Red Dwarf at Eris

If a red dwarf star was as distant from earth as Eris is at it's current distance (96 AU or 14 billion km, from earth 97 from the Sun) it would have less gravitational influence on Earth than Jupiter. The largest red dwarf being about 40% of the mass of the Sun. Indeed a star of that mass could be as close as 80 AU and still not perturb the Earth's orbit. Even with the much lower luminosity of a red dwarf it would easily be the brightest object in our sky. And for me it is easy to conceive of a life bearing world in such a set up, the question is if the gravitational evolution of a disk nebula could produce the result of both an approximately earth mass terrestrial planet around an approximately sun mass star with a much more distant star 80 or more AU away.

At the bottom end a near brown dwarf star of .076 of the Sun's mass could be as close as 5.2 billion km or 34.7 AU. That is just a bit farther out than Neptune's 29 AU from Earth.

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