TOI-1801 b Archives

Interior structure schematic for the interior composition of sub-Neptune models presented in this work. Color is an approximate indicator of temperature (specific values depend on the model). The envelope (∼5% by mass) is a mixture of hydrogen, helium, and heavy elements (Z) represented by either water (Section 3.1) or silicates (Sections 3.2, 3.3). The mantle composition is MgSiO3, and the core composition is Fe16Si. We maintain a 2:1 mass ratio between the core and the mantle. For this work, the EMB represents a steep compositional gradient and thus controls mantle cooling by transferring heat to the envelope via conduction. Since conductive flux alone is insufficient to transport the entire interior heat to the envelope, a steep temperature gradient forms at the EMB, as seen in all models in this work. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

Sub-Neptune Memories I: Implications of Inefficient Mantle Cooling and Silicate Rain

by Keith CowingJanuary 12, 2026January 12, 2026

We explore the evolution of sub-Neptune (radii between ∼1.5 and 4 R⊕) exoplanet interior structures using our upgraded planetary evolution code, APPLE, which self-consistently couples the thermal and compositional evolution […]

Mass-radius diagram for TOI-1801 b, together with all known exoplanets (grey dots) with a precision better than 8% in radius (through transit) and 20% in mass (from RV). The population of young transiting exoplanets (< 900 Myr) with measured masses is plotted as coloured dots, according to their ages. The uncertainties on TOI-1801 b are shown as coloured shaded regions with 1, 2, and 3σ levels of confidence. In the left panel, the iso-density lines are displayed as dashed grey lines. In the remaining panels where the population of exoplanets is plotted along with TOI-1801 b, coloured lines indicate different composition models without gas (middle panel) and with a gas envelope (right panel) from Zeng et al. (2019). In the right panel, the solid and dotted lines show the models with temperatures of 300 K and 500 K, respectively, of the corresponding specific entropy at 100 bar level in the gas envelope. The Earth and Neptune are also depicted as reference. We include B22 and M22 as references because different results have been published for the same planet, and this refers to Barragán et al. (2022) and El Mufti et al. (2023), respectively. -- astro-ph.EP

Exoplanets, -moons, -comets, Habitable Zones, Status Report

TOI-1801 b: A Temperate Mini-Neptune Around A Young M0.5 Dwarf

by Keith CowingOctober 17, 2023October 17, 2023

We report the discovery, mass, and radius determination of TOI-1801 b, a temperate mini-Neptune around a young M dwarf. TOI-1801 b was observed in TESS sectors 22 and 49, and […]

TOI-1801 b

Sub-Neptune Memories I: Implications of Inefficient Mantle Cooling and Silicate Rain

TOI-1801 b: A Temperate Mini-Neptune Around A Young M0.5 Dwarf

White Paper On Phototrophic Biosignatures: Research Priorities For The Search For Life On Other Worlds

Autonomous AI-Cosmoindustry and the Quiet Expansion Filter: A Threshold-Based Resolution of the Fermi Paradox

A Scalable Path to Astrometric Exomoon Discoveries with the Nautilus Space Observatory

20 Years Later: The ALH 84001 Debate in Context with Viking’s Results. Lessons Learned and Portals Opened

Ocean Planet Research: 31 New Species Discovered in Two Weeks of Deep Sea Exploration