Back HR 8799 c Arabic HR 8799 c Catalan HR 8799 c Czech HR 8799 c Spanish HR 8799 c Finnish HR 8799 c French HR 8799 c ID HR 8799 c Italian HR 8799 c Japanese HR 8799 c Korean
 Size comparison of HR 8799 c (gray) with Jupiter. | |
| Discovery | |
|---|---|
| Discovered by | Marois et al. |
| Discovery site | Keck and Gemini observatories in Hawaii |
| Discovery date | November 13, 2008 |
| Direct imaging | |
| Orbital characteristics | |
| ~ 38 AU | |
| ~ 190[1][note 1] y | |
| Star | HR 8799 |
| Physical characteristics | |
| 1.3[2] RJ | |
| Mass | 7+3 −2[3] MJ |
Mean density | 4.702 g/cm3[4] |
| Temperature | 1090+10 −90[1] K |
HR 8799 c is an extrasolar planet located approximately 129 light-years away in the constellation of Pegasus, orbiting the 6th magnitude Lambda Boötis star HR 8799. This planet has a mass between 5 and 10 Jupiter masses and a radius from 20 to 30% larger than Jupiter's. It orbits at 38 AU from HR 8799 with an unknown eccentricity and a period of 190 years; it is the 2nd planet discovered in the HR 8799 system. Along with two other planets orbiting HR 8799, this planet was discovered on November 13, 2008, by Marois et al., using the Keck and the Gemini observatories in Hawaii. These planets were discovered using the direct imaging technique.[1][5][6][7][8] In January 2010, HR 8799 c became the 9th exoplanet candidate to have a portion of its spectrum directly observed (following 2M1207b, DH Tau b, GQ Lup b, AB Pic b, CHXR 73 b, HD 203030 b, CT Cha b and 1RXS J1609b), confirming the feasibility of direct spectrographic studies of exoplanets.[2][9]
- ^ a b c Marois, Christian; et al. (November 2008). "Direct Imaging of Multiple Planets Orbiting the Star HR 8799". Science. 322 (5906): 1348–1352. arXiv:0811.2606. Bibcode:2008Sci...322.1348M. doi:10.1126/science.1166585. PMID 19008415. S2CID 206516630.
- ^ a b Cite error: The named reference
spectrumwas invoked but never defined (see the help page). - ^ Marois; Zuckerman; Konopacky; Macintosh; Barman (2010). "Images of a fourth planet orbiting HR 8799". Nature. 468 (7327): 1080–1083. arXiv:1011.4918. Bibcode:2010Natur.468.1080M. doi:10.1038/nature09684. PMID 21150902. S2CID 4425891.
- ^ "Exoplanet HR 8799 c". Retrieved 29 July 2024.
- ^ "Astronomers capture first images of newly-discovered solar system" (Press release). W. M. Keck Observatory. 2008-11-13. Archived from the original on 2013-11-26. Retrieved 2008-12-02.
- ^ "Gemini Releases Historic Discovery Image of Planetary First Family" (Press release). Gemini Observatory. 2008-11-13. Retrieved 2008-12-02.
- ^ Achenbach, Joel (2008-11-13). "Scientists Publish First Direct Images of Extrasolar Planets". The Washington Post. Retrieved 2008-12-02.
- ^ Fabrycky; et al. (2010). "Stability of the directly imaged multiplanet system HR 8799: resonance and masses". Astrophys. J. 710 (2): 1408–1421. arXiv:0812.0011. Bibcode:2010ApJ...710.1408F. doi:10.1088/0004-637X/710/2/1408. S2CID 11760422.
- ^ Janson, M. (13 January 2010). "VLT Captures First Direct Spectrum of an Exoplanet". ESO. La Silla Observatory: 2. Bibcode:2010eso..pres....2. Retrieved 2010-01-13.
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