GJ 15 A c is a gas giant 36 times the mass of Earth, and appears to have roughly a 20-year orbit around its cool and small parent star. While its temperature is not known, it's likely to be quite cold in this distant, possibly icy orbit, loosely comparable to the orbit of Saturn around our Sun.

Its companion, the innermost world in the system, GJ 15 A b, takes just 11 days to make a full orbit around the star – a "year" on this planet. It weighs in at three times the mass of Earth, qualifying it for the size category known as "super-Earth." It's also super-heated, with an estimated surface temperature of 530 degrees Fahrenheit (276 Celsius)

The orbit of at least the outer world might well have been sculpted by their parent star's distant companion, another red dwarf known as GJ 15 B, although more observations are needed to be sure.

PLANET TYPE
Neptune-like
DISCOVERY DATE
2018
MASS
36 Earths
PLANET RADIUS
0.595 x Jupiter
(estimate)
ORBITAL RADIUS
5.4 AU
ORBITAL PERIOD
20.8 years
ECCENTRICITY
0.27
DETECTION METHOD