Related papers: Multiple mean motion resonances in the HR 8799 pla…
The recent discovery of a three-planet extrasolar system of HR 8799 by Marois et al. is a breakthrough in the field of the direct imaging. This great achievement raises questions on the formation and dynamical stability of the HR 8799…
The noteworthy four-planet HR 8799 system teeters on the brink of gravitational instability and contains an A-type host star which is characteristic of the progenitors of the majority of known white dwarf planetary system hosts. Gozdziewski…
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 towards imaging Earth-like planets. Imaging…
HR\,8799 is a young planetary system composed of 4 planets and a double debris belt. Being the first multi-planetary system discovered with the direct imaging technique, it has been observed extensively since 1998. This wide baseline of…
Context. The HR 8799 system, hosting four giant planets between a warm and cold debris disc, and an extended dusty tail beyond, serves as an ideal laboratory for studying planetary formation and evolution. The debris discs have been…
We consider the limiting case for orbital stability of the companions to HR 8799. This case is only consistent with ages for the system of ~100 Myr, not with the 1 Gyr age proposed from astroseismology. The discrepancy probably arises…
We present new 1--1.25 micron (z and J band) Subaru/IRCS and 2 micron (K band) VLT/NaCo data for HR 8799 and a rereduction of the 3--5 micron MMT/Clio data first presented by Hinz et al. (2010). Our VLT/NaCo data yields a detection of a…
The exoplanetary system of HR 8799 is one of the rare systems in which multiple planets have been directly imaged. Its architecture is strikingly similar to that of the Solar System, with the four imaged giant planets surrounding a warm…
We present a pre-discovery H-band image of the HR 8799 planetary system that reveals all three planets in August 2007. The data were obtained with the Keck adaptive optics system, using angular differential imaging and a coronagraph. We…
Context: The central star of the HR 8799 system is a gamma Doradus-type pulsator. The system harbours four planetary-mass companions detected by direct imaging, and is a good solar system analogue. The masses of the companions are not known…
Understanding the physical processes sculpting the appearance of young gas-giant planets is complicated by degeneracies confounding effective temperature, surface gravity, cloudiness, and chemistry. To enable more detailed studies,…
The discovery of three planetary companions around HR 8799 (Marois et al. 2008) marked a significant epoch in direct imaging of extrasolar planets. Given the importance of this system, we re-analyzed H band images of HR 8799 obtained with…
We present 1.3 millimeter observations of the debris disk surrounding the HR 8799 multi-planet system from the Submillimeter Array to complement archival ALMA observations that spatially filtered away the bulk of the emission. The image…
The HR 8799 system hosts four massive planets orbiting 15 and 80 AU. Studies of the system's orbital stability and its outer debris disk open the possibility of additional planets, both interior to and exterior to the known system. Reaching…
We obtained spectra, in the wavelength range \lambda = 995 - 1769 nm, of all four known planets orbiting the star HR 8799. Using the suite of instrumentation known as Project 1640 on the Palomar 5-m Hale Telescope, we acquired data at two…
Three planets have been directly imaged around the young star HR 8799. The planets are 5-13 Mjup and orbit the star at projected separations of 24-68 AU. While the initial detection occurred in 2007, two of the planets were recovered in a…
In the coming years, high contrast imaging surveys are expected to reveal the characteristics of the population of wide-orbit, massive, exoplanets. To date, a handful of wide planetary mass companions are known, but only one such…
We have generated an extensive new suite of massive giant planet atmosphere models and used it to obtain fits to photometric data for the planets HR 8799b, c, and d. We consider a wide range of cloudy and cloud-free models. The cloudy…
The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a…
The four directly imaged planets orbiting the star HR 8799 are an ideal laboratory to probe atmospheric physics and formation models. We present more than a decade's worth of Keck/OSIRIS observations of these planets, which represent the…