TOI-1899 and Its Jupiter-Like Planet

TOI-1899 is a small, cool red dwarf of spectral type M0, sitting 419 light-years away. Its mass is 0.627 solar masses and its radius is 0.607 solar radii, both smaller than the Sun's, and its temperature of 3840 K is cooler than the Sun's. The star is 7.4 billion years old. One planet orbits this host.

That planet is TOI-1899 b, a Jupiter-like world discovered in 2020 by the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Its radius of 11.1 Earth radii exceeds four times Earth's radius, and its mass estimate of 213 Earth masses is larger than Earth's. It completes one orbit every 29.1 days. Its mean density is 0.859 g/cm³, 0.156 times Earth's.