Latest astronomy noticias

The TOI-5398 system is a young (650 Myr old) and compact multi-planet system with a hot sub-Neptune orbiting interior to a short-period Saturn planet. The radius and mass of both planets have been measured, constraining their bulk composition....

A new analysis of LHS 1140 b and c, two temperate exoplanets orbiting a nearby star, reveals that LHS 1140 b is likely a mini-Neptune with a thin H/He envelope or a water world. LHS 1140 c remains consistent with a rocky planet, but there is a discrepancy in the transit depths measured by Spitzer and TESS. The candidate LHS 1140 d is not detected, and is attributed to stellar activity....

Two new sub-Neptunes, TOI-904 b and c, have been discovered orbiting the early M dwarf TOI-904. The outer planet, TOI-904 c, is the longest-period M dwarf exoplanet found by TESS, with period 84 days and an estimated equilibrium temperature of 217 K. Future mass measurements and transmission spectroscopy of the similar-sized planets in this system could determine whether they are also similar in density and composition, suggesting a common format...

The two planets in the HD 152843 system have nearly equal masses but differing radii, and the outer planet HD 152843 c has the longest orbital period of any known low-density exoplanet. HD 152843 c is also located in the Saturn valley, the observed lack of planets larger than Neptune but smaller than Saturn. The orbital periods of the planets suggest they are near a 5:3 mean motion resonance, and the brightness of the host star and the low densit...

A temperate, highly eccentric sub-Saturn has been discovered orbiting the bright K-dwarf TOI-2134, in addition to an inner mini-Neptune that was discovered three years ago. The outer planet has a radius of 7.27 R⊕ and a mass of 41.86 M⊕, and a high eccentricity of 0.67, positioning it in the habitable zone of its system for part of its orbit. Further observations are needed to fully constrain the orbit of the outer planet and to study the spin-or...

The planet has more than 3 Earth radii and a 16 Earth masses, suggesting a likely volatile-rich planet. Transit timing variations in the system suggest the presence of an outer planet candidate near a 2:1 resonance, with a mass of 6.8 Earths. Further observations are needed to explicitly identify the resonance and further characterize the properties of the system....

A new analysis of exo-Neptune transmission spectra reveals that these planets have very cloudy atmospheres and high metallicity. Colder exo-Neptunes may have clearer atmospheres, making them better targets for future studies and the search for life beyond Earth...

Both planets have short periods and relatively low masses, but Gliese 724 b is the most eccentric single exoplanet yet discovered around an M dwarf....

Astrometric planet candidates around white dwarfs can be confirmed and characterized by combining astrometric data with spectroscopic and photometric data. Radial velocity and infrared photometry can be used to probe the mass of the objects producing some of the astrometric signals, and rule out parts of the brown dwarf and planet mass parameter space....