TOI-1846 b

TOI-1846 b is a confirmed exoplanet discovered using NASA's Transiting Exoplanet Survey Satellite (TESS). It orbits a star in the constellation of Aries and is one of the numerous small exoplanets that populate the "radius valley," a gap in the size distribution of exoplanets that separates rocky super-Earths from gaseous sub-Neptunes. TOI-1846 b is particularly important for ongoing studies of planetary formation and evolution.

Discovery

TOI-1846 b was first identified as a candidate exoplanet by the TESS mission. Subsequent follow-up observations confirmed the planet's existence, and its parameters were refined through advanced modeling techniques, such as global transit modeling.

Characteristics

TOI-1846 b has a radius of approximately 1.79 ± 0.07 Earth radii (R⊕), and it completes an orbit around its host star in approximately 3.93 days. While its mass has not been measured, the planet's composition is likely to be water-rich, based on its position in the radius-density diagram.

The planet falls within the "radius valley" and is located in the region known as the "keystone planets". The radius valley separates rocky super-Earths from gaseous sub-Neptunes and is thought to reflect the different formation mechanisms for these planets. The planet's radius and orbital period of 3.93 days make it an important target for studying the boundary between rocky planets and those with significant gaseous envelopes.

No additional planetary signals were found in the system. Transit-timing variations (TTVs) were investigated using TESS and EXOFASTv2, but no TTVs were detected, suggesting that the planet's orbit is stable, with no significant perturbations from additional planets or other sources.

Atmospheric characterization

Atmospheric studies of the planet may not be as straightforward as for other targets, but it still remains an interesting target for atmospheric characterization. The planet's location in the sparsely populated radius valley and its orbit around a quiet M-dwarf star make it an intriguing object for further observation.

Simulations of transmission spectra using the JWST instruments indicate that the planet could have notable absorption features due to water (H₂O) and methane (CH₄), with the most prominent spectral features detectable in the infrared. Cloud cover is expected to mute the spectral features, particularly in cases of high-altitude clouds.