Q&A: Miscellaneous X-ray Sources
What are the chances that the brown dwarf "solar
flare" was, instead, an impact by another object similar to
the comet that struck Jupiter, creating a massive explosion and
not a flare?
That's an interesting suggestion! The energy liberated by a
comet infall would be about right, the shock wave might produce
high enough temperatures, and the time scale is not
unreasonable. The main difficulty is the probability of such an
event occurring during a random 12 hour observation.