29. 9. 2026The red dwarf star TOI-210 hosts a temperate sub-Neptune exoplanet, confirmed through a combination of transit observations and precise velocity measurements. This planet, designated TOI-210 b, orbits its host star every 9.01 days and maintains an equilibrium temperature of approximately 368 Kelvin. The system serves as a valuable laboratory for studying the composition and atmospheric retention of small, volatile-rich worlds orbiting small, cool stars. TOI-210 b has a mass 6.75 times that of Earth and a radius 2.23 times that of Earth. Its density suggests it is a volatile-rich world, potentially featuring an extended hydrogen-helium atmosphere or a large water-rich interior. These characteristics classify it as either a gas dwarf or a possible water world. Researchers utilized data from the TESS space mission combined with ground-based instruments like NIRPS to analyze the wobbling motion of the star caused by the planet's gravity. This method, known as radial velocity, allowed for the precise calculation of the planet's mass. Additional analysis of the star's movement suggests the potential presence of two additional non-transiting planets in the system with orbital periods of 2.15 and 3.76 days. These candidates have minimum masses of 3.2 and 4.4 Earth masses, respectively, and likely orbit at a slight tilt relative to TOI-210 b. Key findings - TOI-210 b is a sub-Neptune planet with a mass of 6.75 Earth masses and a radius of 2.23 Earth radii. - The planet exists in a temperate environment with an equilibrium temperature of 368 Kelvin. - Composition analysis indicates the planet is likely a gas dwarf with a hydrogen-helium envelope or a substantial water world. - Two additional non-transiting candidate planets with orbital periods of 2.15 and 3.76 days were identified. - The potential additional planets likely possess mutual orbital inclinations higher than 2.3 to 3.5 degrees.
Research with similar tags
stars
exoplanets
news
