Tags

Type your tag names separated by a space and hit enter

Images of a fourth planet orbiting HR 8799.
Nature 2010; 468(7327):1080-3Nat

Abstract

High-contrast near-infrared imaging of the nearby star HR 8799 has shown three giant planets. Such images were possible because of the wide orbits (>25 astronomical units, where 1 au is the Earth-Sun distance) and youth (<100 Myr) of the imaged planets, which are still hot and bright as they radiate away gravitational energy acquired during their formation. An important area of contention in the exoplanet community is whether outer planets (>10 au) more massive than Jupiter form by way of one-step gravitational instabilities or, rather, through a two-step process involving accretion of a core followed by accumulation of a massive outer envelope composed primarily of hydrogen and helium. Here we report the presence of a fourth planet, interior to and of about the same mass as the other three. The system, with this additional planet, represents a challenge for current planet formation models as none of them can explain the in situ formation of all four planets. With its four young giant planets and known cold/warm debris belts, the HR 8799 planetary system is a unique laboratory in which to study the formation and evolution of giant planets at wide (>10 au) separations.

Authors+Show Affiliations

National Research Council Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, British Columbia V9E 2E7, Canada. christian.marois@nrc-cnrc.gc.caNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

21150902

Citation

Marois, Christian, et al. "Images of a Fourth Planet Orbiting HR 8799." Nature, vol. 468, no. 7327, 2010, pp. 1080-3.
Marois C, Zuckerman B, Konopacky QM, et al. Images of a fourth planet orbiting HR 8799. Nature. 2010;468(7327):1080-3.
Marois, C., Zuckerman, B., Konopacky, Q. M., Macintosh, B., & Barman, T. (2010). Images of a fourth planet orbiting HR 8799. Nature, 468(7327), pp. 1080-3. doi:10.1038/nature09684.
Marois C, et al. Images of a Fourth Planet Orbiting HR 8799. Nature. 2010 Dec 23;468(7327):1080-3. PubMed PMID: 21150902.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Images of a fourth planet orbiting HR 8799. AU - Marois,Christian, AU - Zuckerman,B, AU - Konopacky,Quinn M, AU - Macintosh,Bruce, AU - Barman,Travis, Y1 - 2010/12/08/ PY - 2010/11/05/received PY - 2010/11/18/accepted PY - 2010/12/15/entrez PY - 2010/12/15/pubmed PY - 2010/12/15/medline SP - 1080 EP - 3 JF - Nature JO - Nature VL - 468 IS - 7327 N2 - High-contrast near-infrared imaging of the nearby star HR 8799 has shown three giant planets. Such images were possible because of the wide orbits (>25 astronomical units, where 1 au is the Earth-Sun distance) and youth (<100 Myr) of the imaged planets, which are still hot and bright as they radiate away gravitational energy acquired during their formation. An important area of contention in the exoplanet community is whether outer planets (>10 au) more massive than Jupiter form by way of one-step gravitational instabilities or, rather, through a two-step process involving accretion of a core followed by accumulation of a massive outer envelope composed primarily of hydrogen and helium. Here we report the presence of a fourth planet, interior to and of about the same mass as the other three. The system, with this additional planet, represents a challenge for current planet formation models as none of them can explain the in situ formation of all four planets. With its four young giant planets and known cold/warm debris belts, the HR 8799 planetary system is a unique laboratory in which to study the formation and evolution of giant planets at wide (>10 au) separations. SN - 1476-4687 UR - https://www.unboundmedicine.com/medline/citation/21150902/Images_of_a_fourth_planet_orbiting_HR_8799_ L2 - https://doi.org/10.1038/nature09684 DB - PRIME DP - Unbound Medicine ER -