XO-3 b

From Wikipedia, the free encyclopedia

XO-3b[1]
Extrasolar planet List of extrasolar planets
Parent star
Star XO-3
Constellation Camelopardalis
Right ascension (α) 04h 21m 53s
Declination (δ) +57° 49′ 01″
Distance 850 ± 75 ly (260 ± 23 pc)
Spectral type F5V
Orbital elements
Semimajor axis (a) 0.0454 ± 0.00082 AU
Eccentricity (e) 0.26 ± 0.017
Orbital period (P) 3.1915239 ± 0.00023 d
Inclination (i) 84.2 ± 0.54°
Angular distance (θ) 0.175 mas
Longitude of
periastron
(ω) 345.8 ± 7.3°
Time of periastron (T0) 2454024.84 ± 0.02;
2454449.86816 ± 0.00023
(transit time) JD
Semi-amplitude (K) 420 m/s
Physical characteristics
Mass (m) 11.79 ± 0.59 MJ
Radius (r) 1.217 ± 0.073 RJ
Density (ρ) 8.67[citation needed] kg/m3
Surface gravity (g) 21.02[citation needed] m/s²
Discovery information
Discovery date May 30, 2007
Discoverer(s) Krull et al.
Detection method transit & radial velocity
Discovery site Honolulu, Hawaii
Discovery status Published

XO-3b is an exoplanet with more than twelve times the mass of Jupiter, and an orbit around its parent star of more than three days.[2] The radius of this object is 1.217 times that of Jupiter. Its large size of the planet is believed to be caused by the intense heating of its parent star at very small orbit and because of the huge mass the object probably raidiates enough of its internal heat making it glow red hot. Astronomers announced their discovery on May 30th, 2007 at the American Astronomical Society in Honolulu, Hawaii. Its discovery is attributed to the combined effort of amateur and professional astronomers working together on the XO Project using a telescope located on the Haleakala summit in Hawaii.[3]

Dubbed an "oddball" planet, the planet stands out from over 200 other extrasolar planets as the most massive planet found in close proximity to a star, yet the orbit is significantly elliptical instead of circular, as would be expected.[3] It is also considered a transiting planet, passing in front of its parent star during each orbit. It is the third such planet to be found by the XO Project which was specifically created to locate them.[4]

[edit] Controversy

There is currently a debate over the classification of this object as either a planet or a brown dwarf. One of the leading astronomers in this discussion is Christopher Johns-Krull, who indicated that the debate is still quite lively. This is not particularly unusual or strange, as it wouldn't be the first of many brown dwarfs orbiting mother stars.[2]

The light curve that better match the steepness of ingress and egress implies a planetary radius of 1.32 ± 0.15 RJ and a mass of 11.71 ± 0.46 MJ.[1]

[edit] References

  1. ^ a b "XO-3b: A Massive Planet in an Eccentric Orbit Transiting an F5V Star" (2007). The Astrophysical Journal. 
  2. ^ a b Oddball Planet Puzzles Astronomers, Space.com
  3. ^ a b Space oddity: Astronomers discover giant planet, The Times of India
  4. ^ XO-3 b: Supersized planet or oasis in the 'brown dwarf desert'?, EurekAlert!

[edit] External links

Languages