HD 40307 Archives

A schematic diagram of the hycean Lotka-Volterra model we implement in this work. The schematic shows how various parameters in our model are connected in a vertical, one-dimensional water column.

AI - Data - Apps - Cybernetics, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Proxima Centauri, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Ecological Modelling Of Hycean Worlds

by Keith CowingMarch 25, 2026

New observations are opening the possibility of characterising habitable environments in exoplanetary systems, with the recent example of the candidate hycean world K2-18 b.

Top panels: evolution of CHZ and UVH for Trappist-1, Proxima Centauri, GJ 273, GJ 163, K2-18, GJ 832, GJ 357, GJ 229A, HD 40307 and Kepler-62. In each plot the vertical gray line represents the host star age found in the literature and the relative errors (the gray shaded region around the gray line). Yellow, orange and dark orange lines represent the ages at which fraction of systems with at least one rocky planet without a primordial envelope in the CHZ is equal to 20%, 30%, 40% for each system (according to NGPPS model). The dashed line represents the time where each star settled onto the main sequence. Bottom panels: evolution of the fraction of the radial extension of the CHZ that is overlapping the radial extension of the UVZ for three different values of the NUV atmospheric transmission. -- astro-ph.EP

Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

The Time Evolution Of The Ultraviolet Habitable Zone

by Keith CowingSeptember 5, 2024September 5, 2024

For stars hosting Circumstellar Habitable Zone (CHZ) exoplanets, we investigate the time-evolution of their ultraviolet habitable zone (UHZ), the annular region around a star where an exoplanet could experience a […]