The cosmic shoreline concept was introduced to separate planets with atmospheres from those without, by relating the cumulative X-ray and extreme-ultraviolet (XUV) instellation (integrated over the planet’s lifetime) to the […]
GJ 9827 d
Posted inAtmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Ice Giant, Imaging & Spectroscopy, Status Report
Escape Of Water- And Metal-enriched Atmospheres From Compact Hot mini-Neptunes With CHAIN
Recent observations reveal that atmospheric compositions of close-in sub-Neptunes are diverse and can differ strongly from pure H/He-dominated.
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
JWST/NIRISS Reveals The Water-rich Steam World Atmosphere of GJ 9827 d
With sizable volatile envelopes but smaller radii than the solar system ice giants, sub-Neptunes have been revealed as one of the most common types of planet in the galaxy.
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
The Compact Multi-planet System GJ 9827 Revisited With ESPRESSO
GJ 9827 is a bright, nearby K7V star orbited by two super-Earths and one mini-Neptune on close-in orbits. The system was first discovered using K2 data and then further characterized […]