Boffins 'discover first moon outside our solar system'

Boffins 'discover first moon outside our solar system'

Writing in the journal Science Advances, the researchers noted the moon would have to be unusually large to explain the observed light curve, possibly comparable to a body the size of Neptune.

Moons are certainly plentiful in our solar system - the four giant planets host over 200 moons between them - so it is entirely plausible that many (or even most) of the now known exoplanets - nearly 4,000 - should harbour exomoons.

"This would be the first case of detecting a moon outside our Solar System", Kipping, an assistant professor of astronomy, said in a statement. It's assumed to be a gas giant about the size of Jupiter, but ten times as dense.

We know there are some 200 moons in our own solar system, including Earth's aptly named "moon".

One of the authors behind the study - David Kipping from Columbia University in the USA - has been speculating about the possible existence of exomoons, and describing how they might be detected, for the last ten years.

"If confirmed by follow-up Hubble observations, the finding could provide vital clues about the development of planetary systems and may cause experts to revisit theories of how moons form around planets", Kipping said. The exosystem is further similar to our moon, at 1.5 per cent the exoplanet's mass.

The team behind this intriguing discovery, researched more than 250 planets outside our solar system using the space telescope NASA Kepler.

Describing the moment of discovery, scientist David Kipping said: "It was definitely a shocking moment to see that light curve". Both the timing effects and the dimming of the star that we see in the data correspond with the mood model description so the astronomers allocated 40 hours of observation time on the Hubble telescope. On the other hand, the scientists agreed that another planet in Kepler-1625b's vicinity might also cause such turbulence.

Exomoons are hard to find because they are smaller than their companion planet and their transit signal is weak; they also shift position with each transit because the moon is orbiting the planet, researchers said. Three-and-a-half hours later, Hubble detected a much smaller dip in the star's brightness consistent with a large moon trailing the planet. It will take more observation with the Hubble to confirm it.

Later, the team used the powerful lens of the Hubble Space Telescope to observe the planet and found a pair of unexpected abnormalities. The so-called exomoon is considerably larger than our solar system's biggest moon. Kepler 1625b is roughly the same distance from its star as Earth is from the sun.

"Both bodies, however, are considered to be gaseous and therefore unsuitable for life as we know it", Kipping said. During this event, using the Hubble telescope it was measured the systems, like Kepler, it spotted patterns pointing to an exomoon. Exomoons also shift position with each transit because the moon is orbiting the planet. This new moon - if it exists - is also enormous, about the size of Neptune.

The researchers note the planetary wobble could be caused by the gravitational pull of a hypothetical second planet in the system, rather than a moon.

The researchers believe the star system to be 10 billion years old, which means it's had time to evolve.

Related Articles