HATS-40 b: A Jupiter-like Planet in a Distant System

HATS-40 is a star located 4380 light-years away, and it hosts one known planet. The star is 2.07 billion years old, with a mass of 1.56 solar masses, a radius of 2.26 solar radii, and a temperature of 6460 K. Its reported mass, radius, and temperature estimates are all larger or hotter than the Sun's.

The planet, HATS-40 b, is Jupiter-like, a size class that describes a radius exceeding 4 times Earth's radius. It was discovered by the transit method in 2018, when it was observed passing in front of its star and causing a small dip in brightness. HATS-40 b completes an orbit in 3.26 days. Its mass is 505 Earth masses, roughly 1.59 times Jupiter's mass, and its radius is 17.7 Earth radii. Both its reported mass and radius estimates are larger than Earth's. Its mean density is 0.501 g/cm³, 0.091 times Earth's.