Can red dwarf stars have a spectral type of L? We have the &quot;normal&quot; main sequence stars, OBAFGKM. Below K and M are the brown dwarfs, L,T, and Y. Zooming into the area at the edges of M and L, we have spectral types M9, M9.5, L0, and L1. So I am wondering, is there any red dwarf that has a spectral type of L?
Yes. Stars (those objects that are supported by hydrogen fusion) can be as cool as spectral type L2.
Brown dwarfs can be as warm as M4/5 when they are young.
i.e. there isn't a clear spectral type Vs mass relationship. It depends on age too.