Just when the world thought that signs of life outside of Earth have already been found, experts have to cut the excitement short. In a new study, astronomers found that the so-called alien megastructure orbiting around star KIC 8462852 is most probably just a swarm of comets.
In October 2015, scientists discovered a distant star exuding unusual blinking patterns. Majority of stars found by the Kepler telescope, which monitors light fluctuations to determine planets travelling in front of distant suns, do not exhibit the same irregular dimming that KIC 8462852 presents.
The finding then raised assumptions from citizen scientists, who put great emphasis on the brightness measurements that Kepler was able to obtain. Although the numbers suggest that a planet is passing in front of the star, the notable dimming of KIC 8462852 was quantified to have deep brightness dips of about 22 percent. Aside from that, irregular brightness patterns were also noted - something Kepler has not observed before.
The Search for Extraterrestrial Intelligence (SETI) institute were also appalled that the discovery has urged it to turn its radio telescopes to investigate.
Now, in a new study from Iowa University and Massachusetts Institute of Technology, researchers found that the most acceptable explanation for the unusual dimming of KIC 8462852 is the destruction of a cluster of comets.
The investigation involved two different types of infrared wavelengths. The first one was shorter and was consistent with a common star. The second one is longer and exuded infrared components but are not sufficient to achieve detection threshold.
The scientists found that there were no additional infrared emissions thus warranting that neither an asteroid belt collision, huge impacts on a planet nor clouds of debris and rock were present.
The researchers further explained that the comet fragments that come swiftly at an elliptical and arduous orbit form huge clouds of debris, are dimming the star. The clouds created will then move, thus bringing back the star's original brightness and leaving no signs or evidence of excess infrared light.
The situation wherein clusters of comets become fragmented may be consistent with the lack of strong infrared light found in the investigations.
As for the alien megastructure hypothesis, study author Massimo Marengo said they did not look for that.
"We can't really say it is, or is not," Marengo said. "But what the star is doing is very strange." He added that it is interesting to have this kind of situation, which signifies that there is a new physical explanation or a new idea to be discovered.
The study was published in the Astrophysical Journal on Nov. 19.
