HAT-P-11b
Extrasolar planet | List of extrasolar planets | |
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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) |
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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
- ^ 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.
- ^ "Inclined Orbits Prevail in Exoplanetary Systems". January 12, 2011. http://www.subarutelescope.org/Pressrelease/2010/12/20/index.html.
- ^ 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