HR 8799 c
From Wikipedia, the free encyclopedia
|Extrasolar planet||List of extrasolar planets|
|Right ascension||(α)||23h 07m 28.7150s|
|Declination||(δ)||+21° 08′ 03.302″|
|Distance||129 ± 4[note 1] ly|
(39 ± 1[note 1] pc)
|Spectral type||kA5 hF0 mA5 V; λ Boo|
Observation epoch 2008-09-18
|Angular separation||(ρ)||964[note 2] mas|
|Position angle||(θ)||317.06[note 2]°|
|Projected separation||(d)||38 AU|
|Semimajor axis||(a)||~ 38[note 3] AU|
(~ 5600 Gm)
|Orbital period||(P)||~ 190[note 3] y|
|Mass||(m)||10 ± 3 MJ|
|Discovery date||November 13, 2008|
|Discoverer(s)||Marois et al.|
|Detection method||Direct imaging|
|Discovery site||Keck and Gemini|
observatories in Hawaii
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 7 and 13 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 middle known planet 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 of 2010, HR 8799 c became the first exoplanet to have a portion of its spectrum directly observed, demonstrating the feasibly spectrographic studies of exoplanets.
- ^ a b Computed from parallax:
- ^ a b Calculated from the separations in the East and North directions which are −0.657 and 0.706 arcseconds respectively.
- ^ a b Value given assuming the planet's orbit is circular and is being observed face-on.
<references>tag; no input is allowed. Use
- Media related to HR 8799 c at Wikimedia Commons
- "HR 8799 c". Exoplanets. http://media4.obspm.fr/exoplanets/base/planete.php?etoile=HR+8799&planete=c.
|This extrasolar planet related article is a stub. You can help Wikipedia by expanding it.|
fr:HR 8799 cko:HR 8799 cit:HR 8799 c
: There are
<ref>tags on this page, but the references will not show without a