Artist rendering of dusty comets approaching star KIC8462852, an interpretation of the mysterious objects that periodically block out substantial amounts of the star’s light. Known informally as “Tabby’s” star, it was discovered by citizen scientists using Kepler Space Telescope data, and they are looking for ways to continue their work. (NASA/JPL-Caltech)

It’s been eight months since citizen “Planet Hunters”  working with Yale postdoc Tabetha Boyajian announced the discovery of a most unusual star, or rather a star where something most unusual was intermittently and erratically happening.

The puzzle began with some light curve data, taken over a four year period, by the Kepler Space Telescope  The citizen planet hunters pored through reams of data sent back by Kepler looking for signals of planetary transits — the ever-so-slight dimmings of the star caused by the crossing or an orbiting exoplanet.

But the light curve for KIC 8462852 showed dimmings that were anything but slight, and anything but regular.  The Planet Hunters flagged the star for Boyajian’s groups attention, and the mystery star was born.

Theories on what was causing the very large dips ranged from a host of enormous comets, to a violently exploding planet, to an asteroid belt or the presence of close by stars, from an artifact of Kepler’s camera to, finally, an alien megastructure.  (The last was offered by Penn State astronomer Jason Wright as a kind of “Hail Mary” explanation if and when the others are found wanting.  But that’s what got the press.)

Despite years of concerted observing, theorizing and analyzing, Boyajian, Wright the citizen planet hunters and others intrigued by the mystery say they are no closer to an explanation for whatever is passing in front of the star (now informally called “Tabby’s star.”)  NASA has ruled out a technical glitch in the Kepler data, and a range of astronomers have found fault with all the explanations put forward.

But while the quite tantalizing mystery remains, efforts to learn more about the star may have to wind down soon.  The primary Kepler mission is over, so it will provide no more data for this star.  Other space telescopes will not be looking, nor will the major ground-based observatories.  And  the first SETI searches for signals coming from the star has found nothing unusual.

So with options dwindling to learn more, Boyajian, her citizen astronomers and others have begun a grassroots effort to raise $100,000 to buy time at a network of smaller ground-based telescopes around the world.… Read more