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HR 8799 d is an extrasolar planet located approximately 129 light-years away in the constellation of Pegasus, orbiting the 6th magnitude Lambda Boötis star HR 8799. It has a mass between 5 and 10 Jupiter masses and a radius from 20 to 30% larger than Jupiter's. The planet orbits at 24 AU from HR 8799 with an eccentricity greater than 0.04 and a period of 100 years. Upon initial discovery, it was the innermost known planet in the HR 8799 system, but e, discovered later, is now known to be closer to their parent star. Along with two other planets orbiting HR 8799, this planet was discovered on November 13, 2008 by Marois et al., using the Keck and Gemini observatories in Hawaii. These planets were discovered using the direct imaging technique.[2][5][6][7]
 Size comparison of HR 8799 d (gray) with Jupiter. | |
| Discovery | |
|---|---|
| Discovered by | Marois et al. |
| Discovery site | Keck and Gemini observatories in Hawaii |
| Discovery date | November 13, 2008 |
Detection method | Direct imaging |
| Orbital characteristics | |
Semi-major axis | ~24 AU |
| Eccentricity | >0.04[1][note 1] |
Orbital period (sidereal) | ~100[2][note 2] y |
| Star | HR 8799 |
| Physical characteristics | |
Mean radius | 1.2+0.1 −0[2] RJ |
| Mass | 7+3 −2[3] MJ |
Mean density | 4+1.75 −1.1 kg m−3 |
Synodic rotation period | 6.0+11.3 −2.5 h[4] |
Equatorial rotation velocity | ~10.1+2.8 −2.7 km/s[4] |
| Temperature | 1090+10 −90[2] |
Near infrared spectroscopy from 995 to 1769 nanometers made with the Palomar Observatory show evidence of Acetylene, Methane, and Carbon Dioxide, but Ammonia is not definitively detected.[8] In 2021, the further detection of Water and Carbon Monoxide in the planetary atmosphere was made with the Keck Planet Imager and Characterizer (KPIC).[4]
See also
Notes
- The lower limit on the eccentricity is given for the case that the planet is in a 2:1 resonance with HR 8799 c, as suggested by stability constraints.
- Value given assuming the planet's orbit is circular and is being observed face-on.
References
- 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.
- Marois, Christian; Barman, Travis; Zuckerman, B.; Song, Inseok; Patience, Jennifer; Lafrenière, David; Doyon, René (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.
- Marois; Zuckerman; Konopacky; Macintosh; Barman (2010). "Images of a fourth planet orbiting HR 8799". Nature. 468 (7327): 1080–3. arXiv:1011.4918. Bibcode:2010Natur.468.1080M. doi:10.1038/nature09684. PMID 21150902. S2CID 4425891.
- Wang, Jason J.; Ruffio, Jean-Baptiste; et al. (2021-07-14). "Detection and Bulk Properties of the HR 8799 Planets with High Resolution Spectroscopy". arXiv:2107.06949.
- "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.
- B. R. Oppenheimer (2013). "Reconnaissance of the HR 8799 Exosolar System I: Near IR Spectroscopy". The Astrophysical Journal. 768: 24. arXiv:1303.2627. Bibcode:2013ApJ...768...24O. doi:10.1088/0004-637X/768/1/24. S2CID 7173368.
External links
Media related to HR 8799 d at Wikimedia Commons
- "HR 8799 d". Exoplanets. Archived from the original on 2012-03-04. Retrieved 2008-12-02.
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- [en] HR 8799 d
[es] HR 8799 d
HR 8799 d es un planeta extrasolar que se encuentra a aproximadamente 129 años luz en la constelación de Pegaso orbitando la estrella Lambda Bootis HR 8799. Su masa es entre 7 y 13 veces la masa de Júpiter y su radio es entre un 20 % y un 30 % mayor que el de Júpiter. El planeta orbita a una distancia media de 24 UA de su estrella, con una excentricidad de 0,04 y un periodo orbital de 100 años. Es el planeta más conocido del sistema de HR 8799. Junto con otros dos planetas que orbitan HR 8799, este planeta fue descubierto el 13 de noviembre de 2008 por Marois et al., usando el Telescopio Keck y el observatorio Gemini en Hawái. Estos planetas fueron descubiertos usando la técnica de imagen directa.[6][8][9][10]Другой контент может иметь иную лицензию. Перед использованием материалов сайта WikiSort.org внимательно изучите правила лицензирования конкретных элементов наполнения сайта.
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