TOI-261 and Its Two Neptune-Like Worlds

TOI-261 is a star 373 light-years away with two known planets. The host star has a mass of 1.07 solar masses, a radius of 1.28 solar radii, and a temperature of 5890 K. Its reported radius estimate is larger than the Sun's, and its reported temperature is hotter than the Sun's.

Both planets were discovered by transit in 2021, the method in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. TOI-261.01 is a Neptune-like planet with an orbital period of 3.36 days and a radius of 3.04 Earth radii. TOI-261.02 is also Neptune-like, with an orbital period of 13 days and a radius of 3.35 Earth radii. A Neptune-like size class reaches 4 times Earth's radius. Each planet's reported radius estimate is larger than Earth's.

Among the listed planets, TOI-261.01 has the shortest year by reported estimates, at 3.36 days, and the smallest radius by reported estimates, at 3.04 Earth radii. TOI-261.02 has the longest year by reported estimates, at 13 days, and the largest radius by reported estimates, at 3.35 Earth radii.