They've been a staple of science fiction since Luke Skywalker gazed upon an alien sky in Star Wars, and now scientists say binary star systems might be a lot more common than we’d originally thought.
The National Optical Astronomy Observatory (NOAO) reports that approximately half of all exoplanets likely exist in binary star systems — essentially systems that have two suns, a la Tatooine — which makes sense, as binary systems are relatively common once you start looking outside our little corner of the Milky Way.
So, how’d they figure it all out? Basically, astronomers have identified approximately 2,000 exoplanets in various star systems up to this point (with potentially thousands more out there). From there, they looked at all of them to determine if they were in binary systems. Once they added everything up, the team determined that approximately 1,000 were in binary systems — so we’re batting about 50 percent.
If you’re interested in the science, here’s an excerpt from the NOAO report that explains the process of how they made the determination:
Their study makes use of very high spatial resolution observations that were carried out on the WIYN telescope located on Kitt Peak in southern Arizona and the Gemini North telescope located on Mauna Kea in Hawaii. The technique used by the team is called speckle imaging and consists of obtaining digital images of a small portion of the sky surrounding a star of interest, 15 to 25 times a second. The images are then combined in software using a complex set of algorithms, yielding a final picture of the star with a resolution better that that of the Hubble space telescope. By using this technique, the team can detect companion stars that are up to 125 times fainter than the target, but only 0.05 arcseconds away. For the majority of the Kepler stars, this means companion stars with a true separation of a few to about 100 times the Sun-Earth distance. By noting the occurrence rate of these true binary companion stars, the discoveries can be extended to show that half of the stars that host exoplanets are probably binaries.
So, what does this mean for us? Well, for one thing, once we eventually crack warp technology and make it out into space, we’re fairly likely to stumble upon some Tatooine-esque planets once we start exploring. We can’t wait.