It had all the right numbers: It was several times bigger than Jupiter, orbited a host star that is similar in mass to the sun, and is located at the same distance as the earth from sun. If it is verified to be the first moon discovered outside of our Solar System.
Now, David Kipping and Alex Teachey from Columbia University in NY are hoping that in their result and reports have taken every hypothesis in consideration and that they will get independent confirmation and appreciation. If confirmed, this would be the first discovery of a moon outside our Solar System.
Using data from the Hubble Space Telescope and the Kepler Space Telescope, astronomers found 'compelling' evidence for the moon, orbiting the planet Kepler-1625b. Through the Hubble, the team studied Kepler-1625b as it passes between the star that it is orbiting, which is Kepler-1625, and the Earth.
Although the object itself can not be seen, there are hints it exists, according to the researchers: The planet moves around its star in a way that indicates something else is pulling on it gravitationally, probably a moon. With his help, they found a second, much smaller hole in the brightness of the star through 3.5 hours after the transit of the planet.
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. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD. Another dip could well be a moon - known as an exomoon outside our solar system.
David Kipping, the study's second author, said, 'We saw little deviations and wobbles in the light curve that caught our attention'. They watched the planet during its 19-hour transit. Unfortunately, the scheduled Hubble observations ended before the complete transit of the candidate moon could be measured and its existence confirmed. The scientists needed more time and data to confirm the discovery though, and they got it through the Hubble telescope.
Because their transit signals are weaker than those of planets and their positions change as they orbit their parent planets.
"Furthermore, the size we've calculated for this moon, about the size of Neptune, has hardly been anticipated and so that, too, is reason to be careful here". This could cause a wobble in the planet's orbit, causing it to deviate from its predicted location and transit its star earlier than expected. "Both bodies, however, are considered to be gaseous and therefore unsuitable for life as we know it", Kipping added. "When we look for an Earth twin, I think one of the most obvious things you might ask is, 'Does it have a moon twin, ' because that seems to have a large influence", he notes".