HD 210277 b

HD 210277 b is an extrasolar planet orbiting the star HD 210277. It was discovered in September 1998 by the California and Carnegie Planet Search team using the highly successful radial velocity method. The planet is at least 24% more massive than Jupiter. The mean distance of the planet from the star is slightly more than Earth's distance from the Sun. However, the orbit is very eccentric, so at periastron this distance is almost halved, and at apastron it is as distant as Mars is from the Sun.[2]

HD 210277 b[1]
Discovery
Discovered byMarcy et al.
Discovery siteCalifornia and
Carnegie Planet Search
 USA
Discovery date9 Sept 1998
Radial velocity
Orbital characteristics
1.138 ± 0.066 AU (170,200,000 ± 9,900,000 km)
Eccentricity0.476 ± 0.017
442.19 ± 0.50 d
2,450,104.3 ± 2.6
119.1 ± 2.8
Semi-amplitude38.94 ± 0.75
StarHD 210277

    In 2000, a group of scientists proposed, based on preliminary data from the Hipparcos astrometrical satellite, that the planet would have an inclination of 175.8° and a true mass of 18 times Jupiter making it a brown dwarf instead of a planet.[3] However these measurements were later proved useful only for upper limits of inclination.[4] If the planet orbits in the same plane as the claimed circumstellar disk, which seems a plausible assumption, it would have an inclination of 40° and an absolute mass of 2.2 times Jupiter,[5] however later observations failed to confirm the disk's existence.[6][7]

    References
    1. Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701.
    2. Marcy, Geoffrey W.; et al. (1999). "Two New Planets in Eccentric Orbits". The Astrophysical Journal. 520 (1): 239–247. arXiv:astro-ph/9904275. Bibcode:1999ApJ...520..239M. doi:10.1086/307451.
    3. Han; Black, David C.; Gatewood, George (2001). "Preliminary Astrometric Masses for Proposed Extrasolar Planetary Companions". The Astrophysical Journal Letters. 548 (1): L57–L60. Bibcode:2001ApJ...548L..57H. doi:10.1086/318927.
    4. Pourbaix, D.; Arenou, F. (2001). "Screening the Hipparcos-based astrometric orbits of sub-stellar objects". Astronomy and Astrophysics. 372 (3): 935–944. arXiv:astro-ph/0104412. Bibcode:2001A&A...372..935P. doi:10.1051/0004-6361:20010597.
    5. Trilling, D. E.; et al. (2000). "Circumstellar Dust Disks around Stars with Known Planetary Companions". The Astrophysical Journal. 529 (1): 499–505. Bibcode:2000ApJ...529..499T. doi:10.1086/308280.
    6. Beichman, C. A.; et al. (2005). "Planets and Infrared Excesses: Preliminary Results from a Spitzer MIPS Survey of Solar-Type Stars". The Astrophysical Journal. 622 (2): 1160–1170. arXiv:astro-ph/0412265. Bibcode:2005ApJ...622.1160B. doi:10.1086/428115.
    7. Bryden, G.; et al. (2009). "Planets and Debris Disks: Results from a Spitzer/MIPS Search for Infrared Excess". The Astrophysical Journal. 705 (2): 1226–1236. Bibcode:2009ApJ...705.1226B. doi:10.1088/0004-637X/705/2/1226.



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