WASP-171 and Its Jupiter-Like Planet

WASP-171 is a G0 star 2470 light-years away, with a mass of 1.17 solar masses, a radius of 1.64 solar radii, and a temperature of 5970 K. Its age is 5.91 billion years. The star's reported mass estimate is larger than the Sun's, its reported radius estimate is larger than the Sun's, and its reported temperature is hotter than the Sun's. One planet orbits this host.

That planet is WASP-171 b, a Jupiter-like world discovered by transit in 2019. It completes an orbit every 3.82 days and has a mass of 345 Earth masses and a radius of 11 Earth radii. Both its reported radius estimate and its reported mass estimate are larger than Earth's, and its mean density is 1.43 g/cm³, 0.26 times Earth's. As a size class, Jupiter-like means its radius exceeds 4 times Earth's radius. During a transit, the planet passes in front of its star from our viewpoint, causing a small dip in observed brightness; repeated dips help establish orbital periods such as this one.