相关论文: HR 8799: The Benchmark Directly-Imaged Planetary S…
Many extra-solar planets and a few planetary systems have been found indirectly by small periodic radial velocity variations around old nearby stars. The orbital characteristics of most of them are different from the planets in our solar…
The Alpha Centauri AB system is an attractive one for radial velocity observations to detect potential exoplanets. The high metallicity of both Alpha Centauri A and B suggest that they could have possessed circumstellar discs capable of…
The vast diversity of planetary systems detected to date is defying our capability of understanding their formation and evolution. Well-defined volume-limited surveys are the best tool at our disposal to tackle the problem, via the…
Planets orbiting binary systems are relatively unexplored compared to those around single stars. Detections of circumbinary planets and planetary systems offer a first detailed view into our understanding of circumbinary planet formation…
The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a…
Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories.…
We present an analysis of the orbital motion of the four sub-stellar objects orbiting HR8799. Our study relies on the published astrometric history of this system augmented with an epoch obtained with the Project 1640 coronagraph + Integral…
Spectroscopic transiting observations of the atmospheres of hot Jupiters around other stars, first with Hubble Space Telescope and then Spitzer, opened the door to compositional studies of exoplanets. The James Webb Space Telescope will…
Precise radial-velocity measurements for data acquired with the HARPS spectrograph infer that three planets orbit the M4 dwarf star GJ876. In particular, we confirm the existence of planet "d", which orbits every 1.93785 days. We find that…
Exoplanets with radii between those of Earth and Neptune have stronger surface gravity than Earth, and can retain a sizable hydrogen-dominated atmosphere. In contrast to gas giant planets, we call these planets gas dwarf planets. The James…
The James Webb Space Telescope (JWST) will enable the search for and characterization of terrestrial exoplanet atmospheres in the habitable zone via transmission spectroscopy. However, relatively little work has been done to use solar…
Close-by Earth analogs and super-Earths are of primary importance because they will be preferential targets for the next generation of direct imaging instruments. Bright and close-by G-to-M type stars are preferential targets in radial…
The investigation of the atmospheres of closely separated, directly imaged gas giant exoplanets is challenging due to the presence of stellar speckles that pollute their spectrum. To remedy this, the analysis of medium- to high-resolution…
Aims. We aim to detect molecules in the atmosphere of the young forming companion PDS70 b by searching for atmospheric absorption features typical of substellar objects. Methods. We obtained medium-resolution (R$\approx$5075) spectra of the…
During their formative stages, giant planets are fed by infalling material sourced from the background circumstellar disk. Due to conservation of angular momentum, the incoming gas and dust collects into a circumplanetary disk that…
HR8799 is a benchmark system for direct imaging studies. It hosts two debris belts, which lie internally and externally to four giant planets. This paper considers how the four known planets and a possible fifth planet, interact with the…
Two decades after the discovery of 51 Peg b, the formation processes and atmospheres of short-period gas giants remain poorly understood. Observations of eccentric systems provide key insights on those topics as they can illuminate how a…
The architecture of exoplanetary systems is relatively well known inward to 1 AU thanks to indirect techniques, which have allowed characterization of thousands of exoplanet orbits, masses and sometimes radii. The next step is the…
In the Solar System, minor bodies and dust deliver various materials to planetary surfaces. Several exoplanetary systems are known to host inner and outer belts, analogues of the main asteroid belt and the Kuiper belt. We study the…
The primary scientific objective of this Habitable Worlds Observatory (HWO) Science Case Development Document (SCDD) is to measure planetary rotation rates of transiting exoplanets to determine the structure, composition, circulation, and…