One of the lessons we have learned after two decades of exoplanetary science, primarily from the diversity of exoplanets discovered to date, is that various properties of exoplanets depend on the characteristics and evolution of their parent stars. Specifically, stellar X-ray and UV radiation can impact the chemical and physical properties of planetary atmospheres. While UV radiation is primarily absorbed
Some of the 4903 exoplanets discovered and confirmed so far (https://exoplanets.nasa.gov/) orbit very close to their stars. We learnt with the very first planet discovered around a star different than the Sun (51 Pegasi b, discovered in 1995) that planets with very close orbits are possible in nature. 51 Pegasi b, in fact, orbits at about 0.05 Astronomical Units (AU,
Ultra-hot Jupiters are gaseous planets orbiting at close distances from their central stars, with rotation periods shorter than 3 days. Their atmospheres are thus heated, more than 2000 degrees, by the incident radiation emitted by the central star. For this reason, the atmospheres of ultra-hot Jupiters shows peculiar properties compared with planets of other types. For instance, they are affected
