A curious star more than 1,400 light-years from Earth has completely baffled astronomers.
It's so unlike anything we've ever seen, scientists can't entirely discount that it's evidence of an alien civilization.
The star, called KIC 8462852, is so distant the only information we have about it comes from its light curves - the amount of light from the star that makes it back to Earth.
Astronomers have noticed strange blobs around the star blocking out some of its light. The blobs don't seem to be planets because they follow a random pattern rather than a predictable, planet-like orbit.
A giant swarm of comets or a broken-up planet might cause the strange phenomenon, but no particularly convincing astronomical explanations have emerged. That's why some believe the weird blobs might be a Dyson sphere - an enormous group of solar panels orbiting a star to harvest its energy - therefore implying that we may be observing a technological "megastructure" built by aliens.
As Penn State astronomer Kimberly Cartier told Business Insider, however, the media coverage has "gotten a bit out of hand."
Tech Insider has spotted what we think is the best explanation yet for KIC 8462852, and it doesn't involve aliens at all.
Jim Galasyn, a writer for the blog Desdemona Despair, saw a 2013 research paper posted by commenter "Michael" on a story from Centauri Dreams. That paper explains how some stars don't have a uniform brightness level because they're irregularly shaped and "oblate" discs.
As the researchers write in that study:
When a star is oblate, it has a larger radius at its equator than it does at its poles. As a result, the poles have a higher surface gravity, and thus higher temperature and brightness. Thus, the poles are "gravity brightened", and the equator "gravity darkened."
The star becomes oblate (and hence gravity darkening occurs) because the centrifugal force resulting from rotation creates additional outward pressure on the star.
This creates patches of darker and lighter regions within these kinds of stars, so the light curves that make it back to Earth won't look completely uniform. What's more, planets often orbit "obliquely" from Earth's perspective and do not pass directly in front of a star.
So those especially weird light curves from KIC 8462852 could easily be caused by planets passing in front of darker and lighter regions - not alien artifacts floating around it.
In the image from the research paper below, the red sphere represents an oblate star, and the smaller circles illustrate the path that a planet might take around the star. As the planet crosses into darker and lighter patches of the star, it creates the abnormal light curves that you can see below:
For comparison, here is a light curve from KIC 8462852:
Our overlay of both graphics (below), inspired by one of Galasyn's illustrations, isn't scientific. However, it shows how an oblate star and planets orbiting it would better explain the light curves:
T.S. Boyajian et al. (arXiv.org)/J.W. Barnes et al. (The Astrophysical Journal)/Tech Insider
This seems like a more likely explanation than aliens, but just in case it's off, the Search for Extraterrestrial Intelligence (SETI) Institute, an organization that searches for signs of life beyond Earth, is still closely examining the star.
Researchers there have been pointing the ground-based Allen Telescope Array in California at the bizarre star for the past several days.
SETI researcher Doug Vakoch told Business Insider that we should know if it's aliens within the next week or so.