No More Posts Available.

No more pages to load.

    • Source: XO-2

      • XO-2 is a binary star system about 490 light-years (150 parsecs) away in the constellation Lynx. It consists of two components, XO-2N and XO-2S, both of which host planetary systems.


      Star system


      This system is unusual in that the stars are not typically referred to as components A & B, but are designated based on their positions in the sky: XO-2N is the northern star and XO-2S is the southern star.
      Both of the stars are slightly cooler than the Sun and are nearly identical to each other. The system has a magnitude of 11 and cannot be seen with the naked eye but is visible through a small telescope. These stars are also notable for their large proper motions.
      XO-2N and XO-2S have a separation of approximately 4,600 AU.


      Planetary systems


      There is one confirmed exoplanet orbiting XO-2N. XO-2Nb, which is classified as a hot Jupiter, was discovered by the XO Telescope using the transit method around XO-2N in 2007. It was initially the only known planet in the system and was referred to as XO-2b. A long-period variation in the radial velocity of XO-2N was detected in 2015, which could be explained by either a second planet or a stellar activity cycle. The stellar activity explanation is considered more likely, and is further supported by a 2024 study.
      Two planets were reported to orbit around XO-2S in 2014 using the radial velocity method. One of them is Jupiter-mass and another has a mass comparable to Saturn. A 2024 study found evidence for a third, super-Jupiter mass planet around XO-2S.


      See also


      HD 20781 and HD 20782
      HD 133131
      Lists of exoplanets


      References




      Further reading


      Fernandez, Jose M.; et al. (2009). "The Transit Light Curve Project. XII. Six Transits of the Exoplanet XO-2b". The Astronomical Journal. 137 (6): 4911–4916. arXiv:0903.2687. Bibcode:2009AJ....137.4911F. doi:10.1088/0004-6256/137/6/4911. S2CID 7113991.
      Narita, Norio; et al. (2011). "XO-2b: a Prograde Planet with a Negligible Eccentricity and an Additional Radial Velocity Variation". Publications of the Astronomical Society of Japan. 63 (6): L67–L71. arXiv:1110.6136. Bibcode:2011PASJ...63L..67N. doi:10.1093/pasj/63.6.l67. S2CID 119269227.
      Sing, D. K.; et al. (2011). "Gran Telescopio Canarias OSIRIS transiting exoplanet atmospheric survey: detection of potassium in XO-2b from narrowband spectrophotometry". Astronomy and Astrophysics. 527 A73. arXiv:1008.4795. Bibcode:2011A&A...527A..73S. doi:10.1051/0004-6361/201015579. S2CID 56545385.


      External links


      NASA PlanetQuest: Planet race heats up: 1 month, 32 discoveries
      "XO-2". Exoplanets. Archived from the original on 2016-03-03. Retrieved 2009-04-28.

    Kata Kunci Pencarian: