By Jonathan Hepburn
Uncommon behaviour from a distant star is possibly the result of a family of comet fragments on a hugely elliptical orbit, not a giant structure built by an alien civilisation, astronomers say.
“What the star is carrying out is quite strange,” Associate Professor Massimo Marengo from Iowa State University mentioned in a statement.
So strange, in truth, that astronomer Jason Wright from Penn State University published a paper in the Astrophysical Journal suggesting that an alien megastructure could be to blame.
“Aliens ought to constantly be the really last hypothesis you think about, but this looked like anything you would count on an alien civilization to build,” Professor Wright told The Atlantic.
The star KIC 8462852, about 1,500 light years away in the Milky Way galaxy, was found by NASA’s Kepler Space Telescope in 2009 and has been observed ever given that.
In October this year, citizen scientists examining Kepler information on-line reported that it was displaying normal and extreme dips in brightness.
Examining the light from distant stars is a excellent way to locate exoplanets, explained astronomer Phil Plat on his weblog Poor Astronomy.
Nevertheless, Dr Plait, who worked on the Hubble Space Telescope while at NASA, said that even though stars may possibly show a typical dimming of 1 per cent when a planet the size of Jupiter passes in front of it, KIC 8462852 was dimming by as much as 22 per cent and on an irregular basis.
The astronomers who discovered this behaviour eliminated gear error and starspots (sunspots, on other stars) as possible explanations.
Alien megastructures a well-liked alternative explanation
A well-liked explanation in on-line commentary was a Dyson sphere, a hypothetical megastructure that surrounds a star and captures most or all of its power output.
Dyson spheres have been proposed by science fiction writer Olaf Stapledon in 1937, but named right after theoretical physicist Freeman Dyson following he wrote a 1950 paper suggesting that the infrared output of stars could be examined as a way of discovering alien civilisations.
It has been extensively reported in recent years that Mr Dyson wishes the concept of a Dyson sphere was not named right after him, and that he thinks a cloud of objects surrounding a star is more most likely than a single structure.
The most recent evaluation of information from KIC 8462852, published in Astrophysical Journal Letters, examined information from NASA’s Spitzer Space Telescope from January 2015, two years soon after the Kepler measurements that located the anomaly.
No infrared emissions were found from any debris around the star, permitting the researchers to reject many explanations that incorporated collisions, which create heat.
A cloud of comets the most probably lead to
“The lack of strong infrared excess two years after the events responsible for the unusual light curve observed by Kepler further disfavours the scenarios involving a catastrophic collision in a KIC 8462852 asteroid belt, a giant effect disrupting a planet in the program, or a population of dust-enshrouded planetisimals (a cloud of rocks and debris)”, the researchers wrote in the paper.
“The scenario invoking the fragmentation of a family of comets on a extremely elliptical orbit is alternatively consistent with the lack of sturdy infrared excess identified by our evaluation.”
However, the researchers are not capable to entirely discount the idea of an alien megastructure.
“We can not really say it is, or is not,” stated lead researcher Associate Professor Massimo Marengo from Iowa State University.
“But what the star is performing is extremely strange. It really is intriguing when you have phenomena like that. Usually it means there’s some new physical explanation or a new notion to be found.”
Professor Marengo said that when pulsars, which emit robust radio pulses, exactly where first noticed, the very first a single discovered was named LGM-1 soon after “Small Green Men”.
“We may possibly not know however what’s going on around this star, but that is what tends to make it so exciting,” he said.
Topics: stars, science-and-technology, space-exploration, astronomy-space, united-states