Astronomers might have spotted one of the first exomoons

 

The discovery of a second exomoon candidate hints at the possibility that exomoons may be as common as exoplanets.

We have now confirmed the existence of more than 4,000 exoplanets, or planets outside our solar system, which are teaching us about how planets and systems form and could even aid us to locate other habitable worlds. Still, one object that’s harder to detect is an exomoon. Astrophysicists think it’s very likely that moons exist outside our solar system, but because they are usually so small they are very hard to identify. However, astrophysicists from Columbia University believe they may have located evidence of an exomoon.

 

The potential exomoon, which is very large and is orbiting a Jupiter-sized planet called Kepler 1708b, is located about 5,500 light-years away. It is the second candidate exomoon discovered by the astronomers, headed up by David Kipping. “Astronomers have found more than 10,000 exoplanet candidates so far, but exomoons are far more challenging,” told Kipping in a statement. “They are terra incognita.”

 

Kipping and his team of astronomers looked at archival data from NASA’s Kepler telescope and honed in on the coldest gas giant planets. They chose to focus on these exoplanets because the corresponding planets in our solar system, Jupiter and Saturn, both have several moons orbiting them.

 

They investigated through data on 70 planets before finding the signal of the one exomoon candidate. Being super-sized meant that this signal stood out, and if more candidates are discovered in the future, they possibly won’t be so large. “The first detections in any study will generally be the weirdos,” Kipping explained. “The big ones that are simply easiest to discover with our limited sensitivity.”

 

Researchers will need to gather more data before they can confirm whether the candidate is in fact an exomoon, or whether it’s just a quirk in the data. It’s probable that the signal could be caused by the planet interacting with its star, or noise from the Kepler instrument. So for now, Kippling and his team will continue to search for more evidence about whether this is in fact a moon beyond our solar system.

 

The research is published in the journal Nature Astronomy.