Something—we’re not sure what—is radically dimming a star’s light

Of all the stars in the Kepler field of view, KIC 8462852 seems to be a special snowflake. (credit: NASA)

NASA’s Kepler spacecraft, designed to discover planets orbiting distant stars, has turned up something that’s decidedly not a planet. And at this point, that’s pretty much all we can say about it—except that it’s a mystery.

A star that Kepler has been observing, KIC 8462852, underwent several periods of dimming. This is exactly what Kepler was built to look for, because a slight dimming in a star’s light can indicate the presence of a planet passing in front of it. But this is no slight dip in the star’s light output—it dims by a full 20 percent. That's way too much change for any transiting planet to produce. So, as two researchers titled their paper, “Where’s the Flux?”

The paper exhaustively examines various possible identities for the phenomena. They settle on a most likely scenario, but clearly this is one of the many cases in science where future work is needed.