Related papers: Extended habitability of exoplanets due to subglac…
High levels of X-ray and UV activity on young M dwarfs may drive rapid atmospheric escape on temperate, terrestrial planets orbiting within the liquid water habitable zone. However, secondary atmospheres on planets orbiting older, less…
The existence of water in extrasolar planetary systems is of great interest as it constrains the potential for habitable planets and life. Here, we report the identification of a circumstellar disk that resulted from the destruction of a…
Whereas the Solar System has Mars and Europa as the best candidates for finding fossil/extant life as we know it - based on complex carbon compounds and liquid water - the 263 (non-pulsar) planetary systems around other stars as known at 15…
Thousands of exoplanets orbit nearby stars, showcasing a remarkable diversity in mass, size, and orbits. With the James Webb Space Telescope now operational, we are observing exoplanet atmospheres and aiming to reach down to small,…
The population of small, close-in exoplanets is bifurcated into super-Earths and sub-Neptunes. We calculate physically motivated mass-radius relations for sub-Neptunes, with rocky cores and H/He dominated atmospheres, accounting for their…
We have investigated the possible evolutional history of the water ocean on Venus, adopting the one dimensional radiative-convective model,including the parameters as albedo and relative humidity. Under this model, it has the possibility…
The nearby exoplanet Proxima Centauri b will be a prime future target for characterization, despite questions about its retention of water. Climate models with static oceans suggest that an Earth-like Proxima b could harbor a small dayside…
H$_2$-dominated terrestrial exoplanets are highly accessible to atmospheric characterization via transmission spectroscopy, but such atmospheres are generally thought to be unstable to escape. Here, we propose that close-in, eccentric…
The potential habitability of an exoplanet is traditionally assessed by determining if its orbit falls within the circumstellar `habitable zone' of its star, defined as the distance at which water could be liquid on the surface of a planet…
Exoplanets with substantial Hydrogen/Helium atmospheres have been discovered in abundance, many residing extremely close to their parent stars. The extreme irradiation levels these atmospheres experience causes them to undergo hydrodynamic…
The ubiquity of M dwarfs, combined with the relative ease of detecting terrestrial-mass planets around them, has made them prime targets for finding and characterising planets in the "Habitable Zone" (HZ). However, Kepler finds that…
Following the discovery of the first exoplanet candidate transiting a white dwarf (WD), a "white dwarf opportunity" for characterizing the atmospheres of terrestrial exoplanets around WDs is emerging. Large planet-to-star size ratios and…
The detection of habitable worlds is one of humanity's greatest endeavors. So far, astrobiological studies show that one of the most critical components for life development is liquid water. Its chemical properties and its capacity to…
The closest potentially habitable worlds outside our Solar system orbit a different kind of star than our Sun: smaller red dwarf stars. Such stars can flare frequently, bombarding their planets with biologically damaging high-energy UV…
Exoplanets orbiting in the habitable zone around M-dwarf stars have been prime targets in the search for life due to the long lifetimes of the host star, the prominence of such stars in the galaxy, and the apparent excess of terrestrial…
Energy limits that delineate the `habitable zone' for exoplanets depend on a given exoplanet's net planetary albedo (or `Bond albedo'). We here demonstrate that the planetary albedo of an observed exoplanet is limited by the above-cloud…
During the post-main sequence phase of stellar evolution the orbital distance of the habitable zone, which allows for liquid surface water on terrestrial planets, moves out past the system's original frost line, providing an opportunity for…
The ever-expanding catalog of detected super-Earths calls for theoretical studies of their properties in the case of a substantial water layer. This work considers such water planets with a range of masses and water mass fractions (2 to 5…
It is still unclear whether exoplanets in compact multiplanet systems such as TRAPPIST-1 are able to accrete large quantities of volatiles, grow to sufficient mass, and maintain robust atmospheres and hydrospheres. Previous estimates of…
Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study…