Super-Jupiter

An artistic concept of HD 29587 B a brown dwarf orbiting the star HD 29587, estimated to be about 55 Jupiter masses.

A super-Jupiter is an astronomical object that's more massive than the planet Jupiter. For example, companions at the planet–brown dwarf borderline have been called super-Jupiters, such as around the star Kappa Andromedae.[1]

By 2011 there were 180 known super-Jupiters, some hot, some cold.[2] Even though they are more massive than Jupiter, they remain about the same size as Jupiter up to 80 Jupiter masses.[2] This means that their surface gravity and density goes up proportionally with their mass.[2] The increased mass compresses the planet due to gravity, thus keeping it from being larger.[2] In comparison, somewhat lighter planets than Jupiter can be larger, so-called "puffy planets" (gas giants with a large diameter but low density).[3] An example of this may be the exoplanet HAT-P-1b with about half the mass of Jupiter but about 1.38 times larger diameter.[3]

Corot-3b, with a mass around 22 Jupiter masses,[4] is predicted to have an average density of 26.4 g/cm3, greater than osmium (22.6 g/cm3), the densest natural element under standard conditions. Extreme compression of matter inside it causes the high density, because it is likely composed mainly of hydrogen.[5] The surface gravity is also high, over 50 times that of Earth.[4]

In 2012, the super-Jupiter Kappa Andromedae b was imaged around the star Kappa Andromedae,[1] orbiting it about 1.8 times the distance at which Neptune orbits the Sun.[6]

See also

References

  1. 1 2 "Astronomers Directly Image Massive Star's 'Super-Jupiter'". NASA. 19 November 2012. Retrieved 26 June 2013.
  2. 1 2 3 4 Kitchin, Chris (2012). Exoplanets: Finding, Exploring, and Understanding Alien Worlds. pp. 167–168. ISBN 9781461406440.
  3. 1 2 Chang, Kenneth (2010-11-11). "Puzzling Puffy Planet, Less Dense Than Cork, Is Discovered". The New York Times.
  4. 1 2 Deleuil, M.; Deeg, H. J.; Alonso, R.; Bouchy, F.; Rouan, D.; Auvergne, M.; Baglin, A.; Aigrain, S.; Almenara, J. M.; et al. (2008). "Transiting exoplanets from the CoRoT space mission. VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert". Astronomy and Astrophysics 491 (3): 889–897. arXiv:0810.0919. Bibcode:2008A&A...491..889D. doi:10.1051/0004-6361:200810625.
  5. ↑ Baraffe, I.; Chabrier, G.; Barman, T. S.; Allard, F.; Hauschildt, P. H. (2003). "Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458". Astronomy and Astrophysics 402 (2): 701–712. arXiv:astro-ph/0302293. Bibcode:2003A&A...402..701B. doi:10.1051/0004-6361:20030252.
  6. ↑ "Image of the "super-Jupiter" Kappa Andromedae b". NASA/JPL. 19 November 2012. Retrieved 26 June 2013.

Further reading

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