相关论文: Diffuser-assisted Photometric Follow-up Observatio…
GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple JWST GTO programs. Here, we report the first space-based optical transmission spectrum of the planet using two HST/STIS transit…
The study of temperate sub-Neptunes is the new frontier in exoplanetary science. A major development in the past year has been the first detection of carbon-bearing molecules in the atmosphere of a temperate sub-Neptune, K2-18 b, a possible…
We report improved masses, radii, and densities for four planets in two bright M-dwarf systems, K2-3 and GJ3470, derived from a combination of new radial velocity and transit observations. Supplementing K2 photometry with follow-up Spitzer…
All transiting planets are at risk of contamination by blends with nearby, unresolved stars. Blends dilute the transit signal, causing the planet to appear smaller than it really is, or produce a false positive detection when the target…
Using radial-velocity data from the Habitable-zone Planet Finder, we have measured the mass of the Neptune-sized planet K2-25b, as well as the obliquity of its M4.5-dwarf host star in the 600-800MYr Hyades cluster. This is one of the…
The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the Solar System. Orbiting a nearby M2.5 dwarf…
K2-18b, a sub-Neptune orbiting in the habitable zone of an M dwarf, has attracted significant interest following observations with the Hubble Space Telescope (HST) and, more recently, with the James Webb Space Telescope (JWST) that reveal…
We report on the confirmation that the candidate transits observed for the star EPIC 211525389 are due to a short-period Neptune-sized planet. The host star, located in K2 campaign field 5, is a metal-rich ([Fe/H] = 0.26$\pm$0.05) G-dwarf…
We validate a $R_p=2.32\pm 0.24R_\oplus$ planet on a close-in orbit ($P=2.260455\pm 0.000041$ days) around K2-28 (EPIC 206318379), a metal-rich M4-type dwarf in the Campaign 3 field of the K2 mission. Our follow-up observations included…
All transiting planet observations are at risk of contamination from nearby, unresolved stars. Blends dilute the transit signal, causing the planet to appear smaller than it really is, or produce a false positive detection when the target…
We report here on our search for excess power in photometry of Neptune collected by the K2 mission that may be due to intrinsic global oscillations of the planet Neptune. To conduct this search, we developed new methods to correct for…
Radial velocity searches for extrasolar planets have recently detected several very low mass (7-20M_Earth) planets in close orbits with periods <10 days. We consider the prospects for detecting the analogs of these planets in Galactic open…
The ASTEP project aims at detecting and characterizing transiting planets from Dome C, Antarctica, and qualifying this site for photometry in the visible. The first phase of the project, ASTEP South, is a fixed 10 cm diameter instrument…
AU Mic~b is a Neptune size planet on a 8.47-day orbit around the nearest pre-main sequence ($\sim$20 Myr) star to the Sun, the bright (V=8.81) M dwarf AU Mic. The planet was preliminary detected in Doppler radial velocity time series and…
The star K2-19 hosts a pair of Neptunian planets deep inside the 3:2 resonance. They induce strong transit-timing variations with two incommensurate frequencies. Previous photodynamical modeling of 3.3 years of transit and radial velocity…
We report the results of an analysis of all Spitzer/MIPS 24 micron observations of HD 209458b, one of the touchstone objects in the study of irradiated giant planet atmospheres. Altogether we analyze 2.5 transits, 3 eclipses, and a 58-hour…
We report the discovery of four short period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the…
In this paper, we explore the astrophysical implications of near-field microlensing and its effects on stellar transit observations, with a special emphasis on the Kepler mission. Kepler is a NASA-approved mission whose goal is to detect a…
TOI-282 is a bright (V=9.38) F8 main-sequence star known to host three transiting long-period ($P_b$=22.9 d, $P_c$=56.0 d, and $P_d$=84.3 d) small ($R_p\approx$ 2-4 $R_{\oplus}$) planets. The orbital period ratio of the two outermost…
The prime Kepler mission revealed that small planets (<4 R_earth) are common, especially around low-mass M dwarfs. K2, the re-purposed Kepler mission, continues this exploration of small planets around small stars. Here we combine K2…