Kepler 1780-b is a gas giant exoplanet orbiting the F-type star Kepler 1708, some 5500 light-years
from Earth. Orbiting at a distance of 1.64 astronomical units from its star, the planet has a mass
of 4.6 times that of Jupiter but is estimated to be smaller in size. In 2021, astronomers announced
the likely detection of not only the planet (yellow), but a super-sized satellite orbit in around it
(green), dubbed Kepler 1701-b-i. Unlike the satellites of the Solar System's planets, the 'exomoon'
is not rocky - it's gaseous, somewhat similar to the planet Neptune. Thousands of exoplanets are now
known, but exomoons - although most certainly common - have mostly evaded discovery until now,
because it presents a much more difficult challenge.
Kepler 1708b - V1