HD 210277 b

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HD 210277 b [1]
Exoplanet List of exoplanets
Parent star
Star HD 210277
Constellation Aquarius
Right ascension (α) 22h 09m 29.8657s
Declination (δ) −07° 32′ 55.155″
Apparent magnitude (mV) 6.63
Distance 69.44 ly
(21.29 pc)
Spectral type G0V
Orbital elements
Semi-major axis (a) 1.138 ± 0.066 AU
(170.2 Gm)
    53.45 mas
Periastron (q) 0.596 AU
(89.2 Gm)
Apastron (Q) 1.680 AU
(251.3 Gm)
Eccentricity (e) 0.476 ± 0.017
Orbital period (P) 442.19 ± 0.50 d
(1.2106 y)
Orbital speed (υ) 28.09 km/s
Argument of
(ω) 119.1 ± 2.8°
Time of periastron (T0) 2,450,104.3 ± 2.6 JD
Semi-amplitude (K) 38.94 ± 0.75 m/s
Physical characteristics
Minimum mass (m sin i) 1.29 ± 0.11 MJ
Discovery information
Discovery date 9 Sept 1998
Discoverer(s) Marcy et al.
Discovery method Radial velocity
Discovery site California and
Carnegie Planet Search

Discovery status Published
Database references
Extrasolar Planets
Exoplanet Archive data
Open Exoplanet Catalogue data

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]

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][8]


  1. ^ Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493Freely accessible. Bibcode:2006ApJ...646..505B. doi:10.1086/504701. 
  2. ^ Marcy; Butler, R. Paul; Vogt, Steven S.; Fischer, Debra; Liu, Michael C. (1999). "Two New Candidate Planets in Eccentric Orbits". The Astrophysical Journal. 520 (1): 239–247. arXiv:astro-ph/9904275Freely accessible. 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/0104412Freely accessible. Bibcode:2001A&A...372..935P. doi:10.1051/0004-6361:20010597. 
  5. ^ Trilling; Brown, R. H.; Rivkin, A. S. (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.; Bryden, G.; Rieke, G. H.; Stansberry, J. A.; Trilling, D. E.; Stapelfeldt, K. R.; Werner, M. W.; Engelbracht, C. W.; Blaylock, M.; Gordon, K. D.; Chen, C. H.; Su, K. Y. L.; Hines, D. C. (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/0412265Freely accessible. Bibcode:2005ApJ...622.1160B. doi:10.1086/428115. 
  7. ^ Bryden, G.; Beichman, C. A.; Carpenter, J. M.; Rieke, G. H.; Stapelfeldt, K. R.; Werner, M. W.; Tanner, A. M.; Lawler, S. M.; Wyatt, M. C.; Trilling, D. E.; Su, K. Y. L.; Blaylock, M.; Stansberry, J. A. (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. 
  8. ^ Caer McCabe; Carlotta Pham. "Catalog of withdrawn or refuted resolved Disks". Catalog of Resolved Circumstellar Disks. Retrieved 2010-04-03. 

External links[edit]

Coordinates: Sky map 22h 09m 29.8657s, −07° 32′ 55.155″