Kepler 1625b Has Neptune-Sized Moon, Astronomers Say | Astronomy

As of now, through several space exploration programs scientists have found exoplanets, dwarf planets, asteroids and mysterious galaxies and now researchers at Columbia University have announced that they have found evidence of the first known moon outside our Solar System. Kepler-1625b Exomoon vs Solar System MoonsThe exomoon is much larger than the biggest moon of the solar system, Jupiter's Ganymede. We won't know for sure until researchers can do more tests, of course, but even so, what we do have is very promising. This apparent super-size pairing of a gaseous moon and planet is 8000 light years away.

In the Solar system known eight major planets and their satellites about 200. The researchers say this may yield new insights into the development of planetary systems and may cause experts to revisit theories of how moons form around planets. They say the first exomoon is rather unusual because of its larger size, which is comparable to the diameter of our solar system's Neptune.

Only one planet held promise for hosting a moon, one around the star known as Kepler-1625, which is about the size of our sun but older. Or perhaps, like Earth's moon, it is actually a product of its planet, formed in some catastrophic collision.

Compelling evidence for it to be an exomoon came when they noticed a slight transit - a dimming in brightness of around 0.05% - occurring just after the exoplanet transit. Now, two scientists from Columbia University in New York (USA) have used the incomparable capabilities of the NASA/ESA Hubble Space Telescope to study the star Kepler-1625, 8,000 light-years away, and its planet in more detail. At this size, the moon, tentatively designated Kepler-1625b-i, is likely to be gaseous as well.

Researchers caution that the moon hypothesis is tentative and must be confirmed by follow-up Hubble observations, according to NASA's website.

Since moons outside our solar system - known as exomoons - can not be imaged directly, their presence is inferred when they pass in front of a star, momentarily dimming its light. "But we knew our job was to keep a level head testing every conceivable way in which the data could be tricking us until we were left with no other explanation".

The researchers monitored the planet before and during its 19-hour-long transit across the face of the star. In the case of earth and sun, for example, since both bodies have mass, both exert gravitational pull on each other.

Both of these data points are best explained if a huge Neptune-sized moon is orbiting Kepler 1625b.

Co-author Teachey, stated "A companion moon is a simplest and most natural explanation for the second dip in the light curve and the orbit-timing deviation".

Like its moon, Kepler-1625b is also bigger than its counterparts in the solar system.

Various attempts have been made previously to confirm or deny that there is a moon outside our solar system.

"If this does pan out and turn into a true discovery, it would be really revolutionary, but I don't think we're quite there yet", says Megan Bedell, an astronomer at the Flatiron Institute in NY. The research team hopes to take another look at the star next May, if there is time available on the Hubble. During this event, using the Hubble telescope it was measured the systems, like Kepler, it spotted patterns pointing to an exomoon.

Vanessa Coleman