Are aliens building a huge energy-generating megastructure around a weirdly dimming star? That way-out hypothesis has suffered another blow, thanks to a study that draws upon infrared as well as ultraviolet observations.
The star, known as KIC 8462852 or Tabby’s Star, first came to attention two years ago when citizen scientists sifting through data from NASA’s Kepler space telescope noticed some unusually drastic dips in its brightness. The star’s nickname comes from Tabetha “Tabby” Boyajian, the Yale astronomer who oversaw those observations.
Another astronomer, Penn State’s Jason Wright, mused that the data could be explained by the construction of a huge orbital structure known as a Dyson sphere — although he cautioned that “aliens should always be the very last hypothesis you consider.”
Since then, however, the alien hypothesis has been very much considered — along with more mundane explanations such as swarms of comets, stellar variability or clouds of gas and dust. Further observations found that KIC 8462852, which is about 1,500 light-years away in the constellation Cygnus, has been going through a long-term dimming trend.
The latest findings, published in the Astrophysical Journal, indicate that the long-term dimming is due to the effect of obscuring streams of dust.
Astronomers analyzed data from NASA’s Spitzer Space Telescope and Swift spacecraft, as well as from the Belgian AstroLAB IRIS observatory, and compared the levels of dimming in infrared vs. ultraviolet wavelengths.
They found that the ultraviolet light dimmed significantly more than the infrared light. That fits the pattern for starlight shining through a haze of dust particles no bigger than about a ten-thousandth of an inch.
The author of this article is a hack science writer who specializes in debunking and trivializing important scientific matters. This mystery is by no means solved, as the additonal post from Scientific American will show. To read more, click here.