Red dwarfs are not failed stars. They are the lowest mass objects capable of nuclear fusion. Brown dwarfs are failed stars. Brown dwarfs officially start at 13 Jupiter masses, & have a maximum mass of 75 Jupiter’s. Beyond that mass, fusion starts & the object is officially a star.
Well failed star is an erroneous term it just means any star that is not bright enough and hot enough that any world around it could sustain life (at least carbon-based as we know it to be).
Any world close enough to have liquid water would be so close as to be irradiated beyond anything we consider to be survivable and probably tidily locked to boot.
It’s still a star in the real sense of the term just quite dim and cool.
Red dwarfs are not failed stars. They are the lowest mass objects capable of nuclear fusion. Brown dwarfs are failed stars. Brown dwarfs officially start at 13 Jupiter masses, & have a maximum mass of 75 Jupiter’s. Beyond that mass, fusion starts & the object is officially a star.
Well failed star is an erroneous term it just means any star that is not bright enough and hot enough that any world around it could sustain life (at least carbon-based as we know it to be).
Any world close enough to have liquid water would be so close as to be irradiated beyond anything we consider to be survivable and probably tidily locked to boot.
It’s still a star in the real sense of the term just quite dim and cool.