"Maehara's point that the 365 superflares don't show hot-Jupiters is a pretty strong argument against the hot-Jupiter theory," says Schaefer. "No one has proposed any alternative."
Maehara thinks they could be caused by starspots much larger than any sunspot found on the sun.
"However it is not well understood why and how such large starspots are formed on solar-type stars," he says.
"This very much is a mystery and a challenge for classic astrophysics," says Schaefer.
Scientists don't believe our sun has ever generated such a superflare. If one had, it likely would have triggered enough chemical change in the atmosphere to set off a mass-extinction of life on Earth. The only mass extinctions in geologic record have been tied to asteroid strikes, volcanic activity and related climatic change.
Ironically, a superflaring star may be a good place to look for habitable planets, Schaefer adds.
"Superflares might provide the high-energy radiation required to create organic molecules, so perhaps superflare systems are a good place to look for alien life that has evolved to avoid the effects of the huge flares," he says.