Space

Extraterrestrial Life Or Just Exocomets: The Hunt For Alien Megastructure Clues For The Crazy Transit Signal

Johnson Denise
First Posted: May 18, 2016 08:43 AM EDT

After all the commotion relating to a certain star that was investigated by NASA's Kepler Scape Telescope last October, astronomers have been exhausting all their efforts to find a natural explanation for the strange transit signal. Though it has turned into something of an epic endeavor, astronomers are zeroing in on the most likely candidate.

As every one of you may have already known, the Kepler Telescope is used to detect the movement of exoplanets around other stars. The strength of the telescope is that it is able to detect even the very faint drop in starlight of surprisingly small worlds of Earth-like dimensions, sometimes smaller, at tens up to hundreds of light-years distant. Newsyac.com has reported that the Kepler's database is outrageously huge, so in order to help astronomers identify transit signals, the crowd-sourcing group Planet Hunters probes into the signals.

A signal, which originated from a star designated as KIC 846852, which was eventually given the name "Tabby's Star" after the one who discovered it, Tabetha S. Boyajian, was dramatic. A series of transit signals made the star's brightness to dip up to 20 percent. For a mission that deals in transits that usually dim starlight by fractions of a percent, you can see why the signal caused a whirl.

This signal was confirmed to be real, so there was no error in the instrument or the analysis. This gave astronomers a chance to start working on possible explanations. And it wasn't long before the "alien" card was pulled and the world's media latched questions like, Was this the first direct evidence of an advanced alien civilization building some kind of "megastructure" around their host star? Could this be the first evidence of a partially built "Dyson Sphere"?

However, according to Discovery News, scientists being the party pooper that they are were already pointing their fingers at other, more reasonable explanations, and it didn't involve aliens. One idea they have identified gravitated towards the possibility of a planetary collision. Although the likelihood of looking in the right place at the right time to see the exo-smashup was slim, it doesn't mean it didn't happen. Another idea was focused on a wide swarm of comets blotting out the star from our viewpoint.

Indeed, the latter explanation had some meat as there was another nearby star that could have destabilized Tabby's Star's Oort Cloud, which is the region surrounding a star that is thought to harbor countless billions of ancient icy bodies waiting to be knocked off by their gravitational perch and fall through the inner star system.

A recent research by astronomers from Harvard-Smithsonian Center for Astrophysics have studied Tabby's star using the Submillimeter Array and the James Clerk Maxwell Telescope, located atop Mauna Kea in Hawaii, in an effort to possibly track down dust associated with a planetary collision. The warm dust that would be produced by such an event should glow in emissions at submillimeter and millimeter wavelengths. But found none.

Although the signal off some warm dust in the system may be undetectable, this negative result puts some tough restraints on the amount of dust in the system. There's simply not enough dust there to support the collision hypothesis, but might be consistent with a complete breakup of 30 massive Halley-like comets blocking the starlight from view.

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