scispace - formally typeset
Open AccessJournal ArticleDOI

Direct imaging of multiple planets orbiting the star HR 8799.

Reads0
Chats0
TLDR
High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units.
Abstract
Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step toward imaging Earth-like planets. Imaging detections are challenging because of the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our solar system.

read more

Citations
More filters
Journal ArticleDOI

Stellar Multiplicity

TL;DR: In this article, the authors summarize the current empirical knowledge of stellar multiplicity for Main Sequence stars and brown dwarfs, as well as among populations of Pre-Main Sequence stars, and embedded protostars.
Journal ArticleDOI

Images of a fourth planet orbiting HR 8799

TL;DR: The HR 8799 planetary system, with its four young giant planets and known cold/warm debris belts, is a unique laboratory in which to study the formation and evolution of giant planets at wide (>10 au) separations.
Journal ArticleDOI

A Giant Planet Imaged in the Disk of the Young Star β Pictoris

TL;DR: It is shown that the ~10-million-year-oldβ Pictoris system hosts a massive giant planet, β Pictoris b, located 8 to 15 astronomical units from the star, which confirms that gas giant planets form rapidly within disks and validates the use of disk structures as fingerprints of embedded planets.
Journal ArticleDOI

Resolved Images of Large Cavities in Protoplanetary Transition Disks

TL;DR: In this article, the authors present new and archival high angular resolution (03 40-75 AU) Submillimeter Array (SMA) observations of the 880 μm (340 GHz) dust continuum emission from 12 transition disks in nearby star-forming regions.
Journal ArticleDOI

First light of the Gemini Planet Imager

TL;DR: Observations ofBeta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing, and fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions.
References
More filters
Journal ArticleDOI

Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945

TL;DR: In this article, the authors present evolutionary models for cool brown dwarfs and extra-solar giant planets and show that irradiation effects can substantially affect the radius of sub-jovian mass giant planets.
Journal ArticleDOI

Angular Differential Imaging: a Powerful High-Contrast Imaging Technique

TL;DR: In this paper, the authors proposed an acquisition strategy and reduction pipeline for speckle attenuation and high contrast imaging is demonstrated to significantly get better detection limits with longer integration times at all angular separations.
Journal ArticleDOI

Giant Planet Formation by Gravitational Instability

TL;DR: In this paper, an alternative to the favored core accretion hypothesis is examined; gravitational instability in the outer solar nebula leading to giant planet formation is examined, and three-dimensional hydrodynamic calculations of protoplanetary disks show that giant gaseous protoplanets can form with locally isothermal or adiabatic disk thermodynamics.
Journal ArticleDOI

The distribution of mass in the planetary system and solar nebula

TL;DR: In this paper, a model of the solar nebula is constructed by adding the solar complement of light elements to each planet, using recent models of planetary compositions, and uncertainties in this approach are estimated.
Proceedings ArticleDOI

Filter Bank Common Spatial Pattern (FBCSP) in Brain-Computer Interface

TL;DR: A novel filter bank common spatial pattern (FBCSP) is proposed to perform autonomous selection of key temporal-spatial discriminative EEG characteristics and shows that FBCSP, using a particular combination feature selection and classification algorithm, yields relatively higher cross-validation accuracies compared to prevailing approaches.
Related Papers (5)