The first rebuttal of Schaefer’s claim came from Hippke’s team who concluded that the long-term dimming of Boyajian’s star was not really there, but only an artifact of the hodge-podge nature of the photographic plates themselves.

However, as Schaefer was quick to point out in an immediate online response, Hippke had failed to account for many of the quirks that make working with photographic plates a “lost art” of astronomy, effectively refuting Hippke’s contradictory claim.

In reply to Schaefer’s precise but caustic counterargument, Hippke’s team and the Vanderbilt/Lehigh collaboration combined their efforts to re-examine the DASCH data on Boyajian’s star with more expertise. They conclude that Boyajian’s star indeed does not exhibit any extraordinary dimming over the past century. This time, their results have been peer-reviewed and recently accepted for publication in the Astrophysical Journal.

So where does this all leave us? If Hippke is correct (and his paper is persuasive) then we are back where we were before Schafer’s claim, and the Kepler data remain the only strange thing about this star. But that still brings us no closer to a resolution of the mystery—that will require additional observations.

Efforts at the Allen Telescope Array to detect obviously artificial radio signatures came up empty, showing us that there were no very strong alien signals being sent when they looked. Our team still hopes to be awarded time on the much more powerful Green Bank Telescope to take a closer look.

On the side of natural explanations, if a recent cataclysmic event in the system created a large cloud of dust responsible for the dimming events Kepler saw, then it’s possible a heat signature will show up at some point in the next couple of years; another team of astronomers is using NASA’s Spitzer infrared space telescope to watch for that possibility.

Boyajian herself is coordinating a worldwide effort of professional telescopes to monitor the star regularly for the next several years, to catch the star in the act. Citizen scientists are still on the case, too: the American Association of Variable Star Observers is tracking brightness measurements of the star made by amateur astronomers. When the star dims again, we will use telescopes around the world to measure how much the star dims at different wavelengths. Since different substances have characteristic absorption patterns, this will tell us the composition of the intervening material. For instance, if it dims much more at ultraviolet wavelengths than in the infrared, we will know dust is to blame. If we see the characteristic pattern of cometary gases, that will help confirm the cometary hypothesis.

And if we see the same brightness changes at all wavelengths? That would indicate that whatever is blocking the starlight is big and opaque—inconsistent with comets, but consistent with the alien megastructure hypothesis.