Related papers: The Hunt for Planet Nine: Atmosphere, Spectra, Evo…
The atmospheres of close-in planets are strongly influenced by mass loss driven by the high-energy (X-ray and extreme ultraviolet, EUV) irradiation of the host star, particularly during the early stages of evolution. We recently developed a…
We present and analyze three-dimensional data cubes of Neptune from the OSIRIS integral-field spectrograph on the 10-m Keck telescope, from July 2009. These data have a spatial resolution of 0.035"/pixel and spectral resolution of R~3800 in…
We perform modeling investigations to aid in understanding the atmospheres and composition of small planets of ~2-4 Earth radii, which are now known to be common in our galaxy. GJ 1214b is a well studied example whose atmospheric…
We report the analysis of two new spectroscopic observations of the super-Earth 55 Cancri e, in the near infrared, obtained with the WFC3 camera onboard the HST. 55 Cancri e orbits so close to its parent star, that temperatures much higher…
Upcoming space-based coronagraphic instruments in the next decade will perform reflected light spectroscopy and photometry of cool, directly imaged extrasolar giant planets. We are developing a new atmospheric retrieval methodology to help…
We present dayside thermal emission observations of the hottest exoplanet KELT-9b using the new MAROON-X spectrograph. We detect atomic lines in emission with a signal-to-noise ratio of 10 using cross-correlation with binary masks. The…
An unusual orbital element clustering of Kuiper belt objects (KBOs) has been observed. The most promising dynamic solution is the presence of a giant planet in the outer Solar system, Planet Nine. However, due to its extreme distance,…
We present model atmospheres for an Earth-like planet orbiting the entire grid of main sequence FGK stars with effective temperatures ranging from Teff = 4250K to Teff = 7000K in 250K intervals. We model the remotely detectable spectra of…
We investigate the atmosphere of GJ1214b, a transiting super-Earth planet with a low mean density, by measuring its transit depth as a function of wavelength in the blue optical portion of the spectrum. It is thought that this planet is…
From orbit, the visibility of Titan's surface is limited to a handful of narrow spectral windows in the near-infrared (near-IR), primarily from the absorption of methane gas. This has limited the ability to identify specific compounds on…
We describe optical spectroscopic observations of the icy dwarf planet Eris with the 6.5 meter MMT telescope and the Red Channel Spectrograph. We report a correlation, that is at the edge of statistical significance, between blue shift and…
With no analogues in the Solar System, the discovery of thousands of exoplanets with masses and radii intermediate between Earth and Neptune was one of the big surprises of exoplanet science. These super-Earths and sub-Neptunes likely…
Terrestrial planets in the habitable zones (HZs) of low-mass stars and cool dwarfs have received significant scrutiny recently because their shorter orbital periods increase their chances of detection and characterization compared to…
The conditions that a planet must fulfill to be habitable are not precisely known. However, it is comparatively easier to define conditions under which a planet is very likely not habitable. Finding such conditions is important as it can…
Recent transit observations of K2-18b and TOI-270d revealed strong molecular absorption signatures, lending credence to the idea that temperate sub-Neptunes (T$_\mathrm{eq}$=250-400K) have upper atmospheres mostly free of aerosols. These…
Context: Pluto possesses a thin atmosphere, primarily composed of nitrogen, in which the detection of methane has been reported. Aims: The goal is to constrain essential but so far unknown parameters of Pluto's atmosphere such as the…
Characterizing rocky exoplanets is a central endeavor of astronomy, and yet the search for atmospheres on rocky exoplanets has hitherto resulted in either tight upper limits on the atmospheric mass or inconclusive results. The 1.95-REarth…
Uranus and Neptune are the last unexplored planets of the Solar System. I show that they hold crucial keys to understand the atmospheric dynamics and structure of planets with hydrogen atmospheres. Their atmospheres are active and storms…
Amongst the many hundreds of transiting planet candidates discovered by the Kepler Mission, one finds a large number of candidates with sizes between that of the Earth and Neptune. The composition of these worlds is not immediately obvious…
Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and…