Astronomers find strong evidence for the presence of an exomane

Columbia University researchers have found strong evidence of the presence of an exomoon. Moons outside our solar system have not been discovered before. It is about a moon that may orbit planet Kepler-1625b, about 4000 light-years from Earth.

The researchers observed two dips in the brightness of the star Kepler-1625. One dip came from the planet sliding past the star, but then a second, smaller dip followed. This suggests that there must be a second object, in the form of a moon orbiting Kepler 1625b. In addition, the planet’s transit period occurred an hour earlier than predicted. The scientists think that could be explained by the gravity exerted by the moon on the planet. In addition, there were also small deviations in the light curve.

The astronomers have already analyzed data from 284 exoplanets from the Kepler space telescope at an earlier stage. On that basis, they stated a year ago that they might have found an exomoon. To be able to say that with a little more certainty, the astronomers used 40 hours of observation time from the Hubble Telescope to monitor exoplanet Kepler-1625b as the planet passes in front of the star. It was examined to what extent the brightness of the star showed a temporary dip; this is the so-called transit method with which many exoplanets have already been discovered.

According to the astronomers, it is an unusually large moon, comparable in size to Neptune. A definitive answer about the moon may not follow until 2021, when the James Webb telescope is launched. The moon and at least the star and planet are in the constellation Cygnus.

The planet and its presumed moon are located in the habitable zone of Kepler-1625, where relatively normal temperatures exist and so water could exist on a planet with a solid substratum. However, both the moon and the planet are expected to be gas giants, making them basically unsuitable in any search for life.