If it includes only those which sustain hydrogen fusion and have a spectral class of M8 or brighter, I'd say about 10-20% chance that there may be a very dim Red Dwarf hiding somewhere we haven't properly surveyed at 3-4 lightyears or so. Within 2 LY? Not a chance.
If one starts including T- and L-dwarfs, these chances increase, but that's Brown Dwarf territory and muddling the line between planets and stars. There's certainly none within 50 000 AU, but I'd reckon the chances would be slim within 2 LY, especially for L-dwarfs. Finding a T-dwarf at 3 LY? maybe as high as 80%.
-Proterra- t1_irvw2sb wrote
Reply to The vast majority of the 150-400 billion stars in the Milky Way haven't been directly detected. Alpha Centauri is the nearest known star to Sol. What is the probability that there are nearer stars that remain undiscovered? by [deleted]
Depending on your definition of "star".
If it includes only those which sustain hydrogen fusion and have a spectral class of M8 or brighter, I'd say about 10-20% chance that there may be a very dim Red Dwarf hiding somewhere we haven't properly surveyed at 3-4 lightyears or so. Within 2 LY? Not a chance.
If one starts including T- and L-dwarfs, these chances increase, but that's Brown Dwarf territory and muddling the line between planets and stars. There's certainly none within 50 000 AU, but I'd reckon the chances would be slim within 2 LY, especially for L-dwarfs. Finding a T-dwarf at 3 LY? maybe as high as 80%.