V1298 Tau and Its Four Planets

V1298 Tau is a K0 star 353 light-years away. It is very young, with an age of 0.023 billion years. Its mass is 1.1 solar masses, its radius is 1.31 solar radii, and its temperature is 4970 K. The star's reported mass and radius estimates are larger than the Sun's, while its reported temperature is cooler than the Sun's. Four planets are known to orbit this host.

All four planets - V1298 Tau b, c, d, and e - are Jupiter-like in size class and were discovered by transit in 2019. 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.

V1298 Tau b has a mass of 13.1 Earth masses, an orbital period of 24.1 days, and a radius of 9.41 Earth radii. Among the listed planets, it has the second-largest reported mass and the second-largest radius, and the second-longest year.

V1298 Tau c has a mass of 4.7 Earth masses, an orbital period of 8.25 days, and a radius of 5.08 Earth radii. It has the smallest reported mass and smallest radius among the listed planets, as well as the shortest year.

V1298 Tau d has a mass of 6 Earth masses, an orbital period of 12.4 days, and a radius of 6.53 Earth radii. It has the second-smallest reported mass and second-smallest radius, and the second-shortest year among the listed planets.

V1298 Tau e has a mass of 15.3 Earth masses, an orbital period of 48.7 days, and a radius of 10.2 Earth radii. Among the listed planets, it has the largest reported mass and largest radius, and the longest year. Each planet's reported mass and radius estimates are larger than Earth's.