Related papers: Exploring the Sub-Neptune Frontier with JWST
The sizes of small planets have been known to be bi-modal, with a gap separating planets that have lost their primordial atmospheres (super-Earths), and the ones that retain them (mini-Neptunes). Here, we report evidences for another…
Planets with radii between that of the Earth and Neptune (hereafter referred to as sub-Neptunes) are found in close-in orbits around more than half of all Sun-like stars. Yet, their composition, formation, and evolution remain poorly…
The origin and evolution of the sub-Neptune population is a highly debated topic in the exoplanet community. With the advent of JWST, atmospheric studies can now put unprecedented constraints on the internal composition of this population.…
Planets residing within the hot-Neptune Desert are rare, and studying their atmospheres can provide valuable insights into their formation and evolutionary processes. We present the atmospheric characterization of the first known ultra-hot…
The newly detected Earth-mass planet in the habitable zone of Proxima Centauri could potentially host life - if it has an atmosphere that supports surface liquid water. We show that thermal phase curve observations with the James Webb Space…
Current observation techniques are able to probe the atmosphere of some giant exoplanets and get some clues about their atmospheric composition. However, the chemical compositions derived from observations are not fully understood, as for…
Atmospheres of transiting exoplanets can be studied spectroscopically using space-based or ground-based observations. Each has its own strengths and weaknesses, so there are benefits to both approaches. This is especially true for…
Characterizing temperate exoplanet atmospheres remains challenging due to their small size and low temperatures. Recent JWST observations provide valuable data, but their interpretation has led to diverging conclusions. Complementary…
A decade ago, the detection of the first transiting extrasolar planet provided a direct constraint on its composition and opened the door to spectroscopic investigations of extrasolar planetary atmospheres. As such characterization studies…
With the operation of JWST, atmospheric characterization has now extended to low-mass exoplanets. In compact multiplanetary systems, secular spin-orbital resonance may preserve high obliquities and asynchronous rotation even for…
The atmospheres of exoplanets reveal all their properties beyond mass, radius, and orbit. Based on bulk densities, we know that exoplanets larger than 1.5 Earth radii must have gaseous envelopes, hence atmospheres. We discuss contemporary…
Some sub-Neptune planets may host habitable conditions; for example "Hycean" worlds with H2 envelopes over liquid water oceans can maintain potentially hospitable pressures and temperatures at their surface. Recent JWST observations of…
Available JWST observations TRAPPIST-1 system have suggested that several of the planets are likely airless, or possess a very tenuous atmosphere. However, the high atmospheric escape rates expected for these planets suggest that any…
The best-characterized exoplanets to date are planets on close-in transiting orbits around their host stars. The high level of irradiation and transiting geometry of these objects make them ideal targets for atmospheric investigations.…
We study the prospects for life on planets with subsurface oceans, and find that a wide range of planets can exist in diverse habitats with ice envelopes of moderate thickness. We quantify the energy sources available to these worlds, the…
Rocky exoplanet characterization has been a top priority for early James Webb Space Telescope (JWST) science operations. Several milestones have been achieved, including the most precise rocky planet transmission spectra measured to date,…
Seven temperate Earth-sized exoplanets readily amenable for atmospheric studies transit the nearby ultracool dwarf star TRAPPIST-1 (refs 1,2). Their atmospheric regime is unknown and could range from extended primordial hydrogen-dominated…
Highly-irradiated giant exoplanets known as "ultra-hot Jupiters" are anticipated to exhibit large variations of atmospheric temperature and chemistry as a function of longitude, latitude, and altitude. Previous observations have hinted at…
To date, the ability for observers to reveal the composition or thermal structure of an exoplanet's atmosphere has rested on two techniques: high-contrast direct imaging and time-series observations of transiting exoplanets. The former is…
LTT-9779 b is an ultra-hot Neptune (Rp ~ 4.7 Re, Mp ~ 29 Me) orbiting its Sun-like host star in just 19 hours, placing it deep within the "hot Neptune desert," where Neptunian planets are seldom found. We present new JWST NIRSpec G395H…