TOI-561 is a star with 0.79 times the mass of the Sun, and 0.85 times its radius. It is located 279.84 light years away from the solar system and is estimated to be 5 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
TOI-561 is known to have 5 exoplanets in orbit around it.
TOI-561 b was discovered by the Transiting Exoplanet Survey Satellite (TESS) observatory, in 2020-12, using the transit method. Its semi-major axis is 0.01 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of TOI-561 b is 1.590 times the mass of Earth. The radius of TOI-561 b is 1.423 that of Earth. With a mass below 5 Earth masses, a density of 3, and a semi-major axis of 0.01055 astronomical units, TOI-561 b could, potentially, be an ocean world - a planet with no dry land.
TOI-561 c was discovered by the Transiting Exoplanet Survey Satellite (TESS) observatory, in 2020-12, using the transit method. Its semi-major axis is 0.09 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of TOI-561 c is 5.403 times the mass of Earth. The radius of TOI-561 c is 2.878 that of Earth. At more than 10 Earth masses, TOI-561 c is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.
TOI-561 d was discovered by the Transiting Exoplanet Survey Satellite (TESS) observatory, in 2020-12, using the transit method. Its semi-major axis is 0.16 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of TOI-561 d is 11.957 times the mass of Earth. The radius of TOI-561 d is 2.530 that of Earth. At more than 10 Earth masses, TOI-561 d is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.
TOI-561 e was discovered by the Transiting Exoplanet Survey Satellite (TESS) observatory, in 2020-12, using the transit method. Its semi-major axis is 0.33 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of TOI-561 e is 16.008 times the mass of Earth. The radius of TOI-561 e is 2.670 that of Earth. At more than 10 Earth masses, TOI-561 e is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.
TOI-561 f was discovered by the Transiting Exoplanet Survey Satellite (TESS) observatory, in 2020-09, using the transit method. Its semi-major axis is 0.12 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of TOI-561 f is 3.002 times the mass of Earth. The radius of TOI-561 f is 2.320 that of Earth. With a mass below 5 Earth masses, a density of 1.3, and a semi-major axis of 0.1174 astronomical units, TOI-561 f could, potentially, be an ocean world - a planet with no dry land.