TOI-674: A Cool Red Dwarf and Its Jupiter-Like Planet

TOI-674 is an M2 V star located 150 light-years away. The "M2 V" spectral type marks it as a small, cool red dwarf, a main-sequence star whose leading letter and number indicate its temperature class. Its mass is 0.42 solar masses and its radius is 0.42 solar radii, both smaller than the Sun's, while its temperature of 3510 K is cooler than the Sun's. One planet is known to orbit this star.

That planet, TOI-674 b, was discovered by transit in 2021. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness; repeated dips help establish orbital periods. TOI-674 b completes an orbit in 1.98 days. Its radius is 5.25 Earth radii, larger than Earth's, and its mass is 23.6 Earth masses, also larger than Earth's. With a radius exceeding four times Earth's, it falls into the Jupiter-like size class. Its mean density is 0.899 g/cm³, 0.163 times Earth's.