HR 8799 d

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HR 8799 d
Exoplanet Comparison HR 8799 d.png
Size comparison of HR 8799 d (gray) with Jupiter.
Discovery
Discovered by Marois et al.
Discovery site Keck and Gemini
observatories
in Hawaii
Discovery dateNovember 13, 2008
Direct imaging
Orbital characteristics
~24 AU
Eccentricity >0.04 [1] [note 1]
~100 [2] [note 2] y
Star HR 8799
Physical characteristics
1.2+0.1
0
[2] RJ
Mass 7+3
2
[3] MJ
Mean density
5.978 g/cm3 [4]
6.0+11.3
−2.5
  h
[5]
Equatorial rotation velocity
~10.1+2.8
−2.7
  km/s
[5]
Temperature 1090+10
90
[2]

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] [6] [7] [8]

Contents

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. [9] In 2021, the further detection of water and carbon monoxide in the planetary atmosphere was made with the Keck Planet Imager and Characterizer (KPIC). [5]

See also

Notes

  1. 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.
  2. Value given assuming the planet's orbit is circular and is being observed face-on.

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HR 8799 is a roughly 30 million-year-old main-sequence star located 133.3 light-years away from Earth in the constellation of Pegasus. It has roughly 1.5 times the Sun's mass and 4.9 times its luminosity. It is part of a system that also contains a debris disk and at least four massive planets. Those planets, along with Fomalhaut b, were the first exoplanets whose orbital motion was confirmed by direct imaging. The star is a Gamma Doradus variable: its luminosity changes because of non-radial pulsations of its surface. The star is also classified as a Lambda Boötis star, which means its surface layers are depleted in iron peak elements. It is the only known star which is simultaneously a Gamma Doradus variable, a Lambda Boötis type, and a Vega-like star.

<span class="mw-page-title-main">HR 8799 b</span> Jovian planet orbiting HR 8799

HR 8799 b 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 4 and 7 Jupiter masses and a radius from 10 to 30% larger than Jupiter's. It orbits at 68 AU from HR 8799 with an unknown eccentricity and a period of 460 years, and is the outermost known planet in the HR 8799 system. Along with two other planets orbiting HR 8799, the 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.

<span class="mw-page-title-main">HR 8799 c</span> Exoplanet orbiting HR 8799

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. In January 2010, HR 8799 c became the 3rd exoplanet to have a portion of its spectrum directly observed, confirming the feasibility of direct spectrographic studies of exoplanets.

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References

  1. 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.
  2. 1 2 3 4 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.
  3. 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.
  4. "Exoplanet HR 8799 d" . Retrieved 29 July 2024.
  5. 1 2 3 Wang, Jason J.; Ruffio, Jean-Baptiste; et al. (2021-07-14). "Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy". The Astronomical Journal. 162 (4): 148. arXiv: 2107.06949 . Bibcode:2021AJ....162..148W. doi: 10.3847/1538-3881/ac1349 . S2CID   235898867.
  6. "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.
  7. "Gemini Releases Historic Discovery Image of Planetary First Family" (Press release). Gemini Observatory. 2008-11-13. Retrieved 2008-12-02.
  8. Achenbach, Joel (2008-11-13). "Scientists Publish First Direct Images of Extrasolar Planets". The Washington Post . Retrieved 2008-12-02.
  9. B. R. Oppenheimer (2013). "Reconnaissance of the HR 8799 Exosolar System I: Near IR Spectroscopy". The Astrophysical Journal. 768 (1): 24. arXiv: 1303.2627 . Bibcode:2013ApJ...768...24O. doi:10.1088/0004-637X/768/1/24. S2CID   7173368.

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