NGTS-9 b: A Giant Planet Around a Hot Star

NGTS-9 is a single star system 1990 light-years away, and its only known planet is NGTS-9 b. The host star has a spectral type of F8 V and an age of 0.96 billion years. Its mass is 1.34 solar masses, its radius is 1.38 solar radii, and its temperature is 6330 K. The star's reported mass estimate is larger than the Sun's, its radius estimate is larger than the Sun's, and its temperature is hotter than the Sun's.

NGTS-9 b was discovered in 2019 by the transit method, in which a planet passing in front of its star causes a small dip in observed brightness. Repeated dips help establish the planet's orbital period. NGTS-9 b completes one orbit every 4.44 days. Its radius is 12 Earth radii, which is larger than Earth's and places it in the Jupiter-like size class, defined by a radius exceeding four times Earth's. Its mass is 922 Earth masses, larger than Earth's and roughly 2.9 times Jupiter's mass. Its mean density is 2.94 g/cm³, 0.534 times Earth's.