Considering the well-established relationships between stellar mass, surface temp, and luminosity, how unusual would it be to find a star (or brown dwarf) that possesses about half the mass of an average member of its spectral category?
Follow-up questions: If such an anomaly did exist, what sort of phenomena could be responsible? Would it be relatively stable over a human lifespan? Or would it necessarily be a transient phenomenon like most variable stars?
The specific example in question is a brown dwarf with a mass ~7110 times Earth, radius ~12 times Earth's, and a spectral black-body temp of 1400K (placing it in the L8 to L9 spectral class). For a sci-fi story, I've constructed a setting with this brown dwarf, Kabina, in orbit of the star Phi2 Ceti (renamed Bahram in everyday parlance), and multiple colonized planets orbiting both the primary star and the brown dwarf.
On reviewing my notes recently and double-checking the numbers, I realized that late L-class brown dwarfs tend to have a mass 1.5 to 3 times the figure I was working with. Whereas brown dwarfs of similar mass are liable to be less than half as hot and bright.
I've calculated the orbits and surface temps of the orbiting planets based on these numbers, so if I need to fix the properties of my brown dwarf, I need to also rework the planetary orbits in order to maintain habitability. If, on the other hand, I can find a plausible explanation for the anomaly, it becomes a cool little detail of the system to add scientific curiosity, and I don't have to rewrite the calendars I've already drawn up for the colonies in orbit.