Related papers: Giant Planets at Small Orbital Distances

Wide separation gas giant planets present a challenge to current planet formation theories, and the detection and characterisation of these systems enables us to constrain their formation pathways. The WIde Separation Planets In Time…

Because of our relatively low spectral resolution, we compare our observations with Gray's line bisector data by fitting observed line profiles to an expansion in terms of orthogonal (Hermite) functions. To obtain an accurate comparison, we…

Systems hosting multiple giant planets are important laboratories for understanding planetary formation and migration processes. We present a nearly decade-long Doppler spectroscopy campaign from the HIRES instrument on the Keck-I telescope…

We present an analysis of three years of precision radial velocity measurements of 160 metal-poor stars observed with HIRES on the Keck 1 telescope. We report on variability and long-term velocity trends for each star in our sample. We…

We report the discovery of planetary companions orbiting four low-luminosity giant stars with M$_\star$ between 1.04 and 1.39 M$_\odot$. All four host stars have been independently observed by the EXoPlanets aRound Evolved StarS (EXPRESS)…

The direct detection of reflected light from exoplanets is an excellent probe for the characterization of their atmospheres. The greatest challenge for this task is the low planet-to-star flux ratio, which even in the most favourable case…

Hot Jupiters generally do not have nearby planet companions, as they may have cleared out other planets during their inward migration from more distant orbits. This gives evidence that hot Jupiters more often migrate inward via…

We present a broad suite of models of extrasolar giant planets (EGP's), ranging in mass from 0.3 to 15 Jupiter masses. The models predict luminosity (both reflected and emitted) as a function of age, mass, deuterium abundance and distance…

Planet formation models suggest that the formation of giant planets is significantly harder around low-mass stars, due to the scaling of protoplanetary disc masses with stellar mass. The discovery of giant planets orbiting such low-mass…

We constrain the densities of Earth- to Neptune-size planets around very cool (Te =3660-4660K) Kepler stars by comparing 1202 Keck/HIRES radial velocity measurements of 150 nearby stars to a model based on Kepler candidate planet radii and…

More than 450 exoplanets have currently been detected, most of them by the radial velocity (RV) technique. While the majority of exoplanets have been found around main-sequence (MS) FGK stars (M 1.5M*), only a small fraction (- 10%) have…

Direct imaging has confirmed the existence of substellar companions on wide orbits. To understand the formation and evolution mechanisms of these companions, the full population properties must be characterized. We aim at detecting giant…

Our knowledge of the populations and occurrence rates of planets orbiting evolved intermediate-mass stars lags behind that for solar-type stars by at least a decade. Some radial velocity surveys have targeted these low-luminosity giant…

Based on the long-term radial-velocity surveys carried out with the McDonald Observatory 2.7m Harlan J. Smith Telescope from 1988 to the present, we derive upper limits to long-period giant planet companions for 31 nearby stars. Data from…

Since October of 1995, employing Doppler spectroscopy astronomers have discovered as many as 20 giant planets and brown dwarfs, including companions to $\tau$ Boo, 51 Peg, $\upsilon$ And, 55 Cnc, $\rho$ CrB, 70 Vir, 16 Cyg B, and 47 UMa.…

We report the discovery of an exoplanet in microlensing event OGLE-2015-BLG-1649. The planet/host-star mass ratio is $q =7.2 \times 10^{-3}$ and the projected separation normalized by the Einstein radius is $s = 0.9$. The upper limit of the…

High-contrast adaptive optics imaging is a powerful technique to probe the architectures of planetary systems from the outside-in and survey the atmospheres of self-luminous giant planets. Direct imaging has rapidly matured over the past…

In this paper we search for distant massive companions to known transiting gas giant planets that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 planets obtained…

X-rays and extreme ultraviolet radiation impacting on a gas produce a variety of effects that, depending on the electron content, may provide a significant heating of the illuminated region. In a planetary atmosphere of solar composition,…

We calculate as a function of orbital distance, mass, and age the theoretical spectra and orbit-averaged planet/star flux ratios for representative wide-separation extrasolar giant planets (EGPs) in the optical, near-infrared, and…