An international team of astronomers has detected two giant alien worlds circling different stars. The newly-found planets are estimated to have the same mass as Saturn, orbiting the M dwarfs beyond the snow line. The planets were discovered by the researchers as part of the Optical Gravitational Leasing Experiment group, along with the Microlensing Observations in Astrophysics (MOA). OGLE uses the 1.3 m Warsaw Telescope located in Las Campanas Observatory in Chile, while MOA utilizes the 1.8 m MOA II telescope at the Mount John University Observatory that is located in New Zealand.
Gravitational microlensing is considered an invaluable method of detecting new extrasolar planets circling their parent stars relatively close-by. This technique is sensitive to planets orbiting beyond the so-called “snow line”, around relatively faint host stars like M dwarfs or brown dwarfs. The exoplanets are located in the proto-planetary disk, where the water ice may condense and where the gas giant planets are believed to be formed. On the basis of this aspect, understanding the distribution of exoplanets in this region could offer important clues to how planets form.
The newly discovered planets received designation as OGLE-BLG-0132b and OGLE-BLG-1721b. Both of them likely belong to a group of sub-Jupiter-mass planets orbiting M dwarfs beyond the snow line distance.
According to the research, OGLE-BLG-0132b has a mass of about 0.29 Jupiter masses and orbits its parent star at a distance of 3.6 AU. The planet’s host is known to be located about 12,700 light years away, having a mass of approximately 0.54 solar masses. The planetary system where the planet is located is about 20,500 light years away from the Earth.
The research team eventually came to the conclusion that in order to uncover more properties of the two newly discovered planets, follow-up high-resolution imaging observations should be conducted in the future. The Near InfRared Camera located on the James Webb Telescope that will be launched in space by the end of 2018, could reveal important insights about these new Saturn-mass exoworlds.