The tracking of the flaring black hole over more than a year, with multiple telescopes, allowed for an unprecedented level of forensic reconstruction, Lodato notes. "This is the first time that such accurate determination of the star's properties have been done," he says.
It also allowed the researchers to draw some conclusions about the black hole and how much of the star it ultimately consumed. Gezari and her colleagues estimated, based on the properties of the flare and the physical attributes of red-giant cores, that the black hole has a mass of roughly three million suns. (The Milky Way's central supermassive black hole, for comparison, is about four million solar masses.) And by summing up the radiated light from the flaring black hole, the researchers concluded that possibly 10 percent, and perhaps as much as half, of the star ended up being consumed. "A large fraction of the star gets ejected away," Gezari says. "It's a very messy process."