WASP-107b is a
super-Neptunian ice giant exoplanet that is roughly the size of
Jupiter but less than one-tenth of Jupiter's mass, making it one of known lowest density-exoplanets. Its highly extended and low density atmosphere coupled with transiting a moderately bright
orange dwarf star makes it an attractive target for atmospheric characterization via transmission spectroscopy.
Atmosphere Helium was discovered in the planet's atmosphere in 2018, making it the first time helium was discovered on an exoplanet. A follow-up observation with
Keck in 2020 showed that the helium absorption extends beyond
transit-egress.
Extreme ultraviolet radiation from the host star is gradually whittling down the planet's atmosphere, forming a comet-like tail 7 times as long as the radius of the planet. In November 2023, scientists discovered that its atmosphere contains water (H2O)
vapour and
sulfur dioxide (SO2). The clouds on this planet are made up of
silicates. The data, along with the unexpectedly low abundance of
methane (CH4), suggests a hotter interior and a more massive core than previously estimated. Tidal heating, caused by the planet's slightly elliptical orbit, is believed to be the source of the extra internal heat. In September 2024 it was revealed that there is an east-west asymmetry in the atmospheric properties (e.g, climate, cloud structure) of WASP-107b, which previously had not been expected for planet of its type. == See also ==