HAT-P-11b

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HAT-P-11b
Extrasolar planet List of extrasolar planets
Exoplanet Comparison HAT-P-11 b.png
Size comparison of HAT-P-11b (gray) with Neptune.
Parent star
Star HAT-P-11
Constellation Cygnus
Right ascension (α) 19h 50m 50.2469s
Declination (δ) +48° 04′ 51.085″
Apparent magnitude (mV) 9.59
Distance 123 ± 4.2 ly
(38 ± 1.3 pc)
Spectral type K4
Orbital elements
Semimajor axis (a) 0.053+0.0002
−0.0008
AU
Periastron (q) 0.043 AU
Apastron (Q) 0.063 AU
Eccentricity (e) 0.198 ± 0.046
Orbital period (P) 4.8878045±0.0000043[1] d
(0.013381878 ± 0.000000019 y)
Orbital speed (υ) 118 km/s
Inclination (i) 88.5 ± 0.6°
Argument of
periastron
(ω) 355.2 ± 17.3°
Time of transit (Tt) 2454605.89132 ± 0.00032 JD
Physical characteristics
Mass (m) 0.081 ± 0.009 MJ
(26 ± 3 M)
Radius (r) 0.422 ± 0.014 RJ
(4.58 ± 0.15 R)
Density (ρ) 1440 kg m-3
Surface gravity (g) 1.20 g
Discovery information
Discovery date January 2, 2009
Discoverer(s) Bakos et al.
Detection method Transit (HATNet)
Discovery site Cambridge, Massachusetts
Discovery status Published
Database references
Extrasolar Planets
Encyclopaedia
data
SIMBAD data

HAT-P-11b (or Kepler-3b) is an extrasolar planet orbiting the star HAT-P-11. This planet was discovered by the transit method and submitted for publication on January 2, 2009.

This planet is located approximately 123 light-years (38 pc) away in the constellation of Cygnus, orbiting the 10th magnitude K-type star HAT-P-11. This planet was the smallest transiting planet known when first discovered, with a radius about 5 times that of Earth; but is more massive than Gliese 436 b at a true mass of 26 times that of Earth. This planet orbits about the same distance from the star as 51 Pegasi b is from 51 Pegasi, typical of transiting planets. However, the orbit of this planet is eccentric, at around 0.198, unusually high for this hot Neptune. HAT-P-11b's orbit is also highly inclined, with a tilt of approximately 103 degrees relative to its star's rotation.[2]

The HAT-P-11 system is within the field of view of the now operational Kepler spacecraft.[3]

Its radial velocity is drifting and this may be a result of an as-yet-undiscovered planet in the system.[3]

The planet fits models for 90% heavy elements. Expected temperature is 878 ± 15K.[3] Actual temperature must await calculations of secondary transit.

[edit] See also

[edit] References

  1. ^ Dittmann, Jason A.; Close, Laird M.; Green, Elizabeth M.; Scuderi, Louis J.; Males, Jared R. (2009). "Follow-up Observations of the Neptune Mass Transiting Extrasolar Planet HAT-P-11b". The Astrophysical Journal 699: L48–L51. arXiv:0905.1114v2. Bibcode 2009ApJ...699L..48D. doi:10.1088/0004-637X/699/1/L48. 
  2. ^ "Inclined Orbits Prevail in Exoplanetary Systems". January 12, 2011. http://www.subarutelescope.org/Pressrelease/2010/12/20/index.html. 
  3. ^ a b c Bakos, G. Á. et al. (2010). "HAT-P-11b: A Super-Neptune Planet Transiting a Bright K Star in the Kepler Field". The Astrophysical Journal 710 (2): 1724–1745. arXiv:0901.0282. doi:10.1088/0004-637X/710/2/1724. http://iopscience.iop.org/0004-637X/710/2/1724/fulltext/. 

[edit] External links

Media related to HAT-P-11b at Wikimedia Commons

Coordinates: Sky map 19h 50m 50.2469s, +48° 04′ 51.085″

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