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Kepler-80

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Kepler-80
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 44m 27.0201s[1]
Declination 39° 58′ 43.5938″[1]
Apparent magnitude (V) 14.804
Characteristics
Spectral type M0V[2]
Astrometry
Proper motion (μ) RA: −1.380±0.037[1] mas/yr
Dec.: −7.185±0.046[1] mas/yr
Parallax (π)2.6780 ± 0.0210 mas[1]
Distance1,218 ± 10 ly
(373 ± 3 pc)
Details
Mass0.730 M
Radius0.678 R
Luminosity0.170 L
Temperature4540 K
Metallicity [Fe/H]-0.56 [3] dex
Rotation25.567±0.252 days[4]
Other designations
KOI-500, KIC 4852528, 2MASS J19442701+3958436
Database references
SIMBADdata
KICdata

Kepler-80 is a star in the constellation Cygnus with six planets.[5][6][7]

Planetary system

The discovery of five planets orbiting the star was announced in October 2012. The planets orbit very near the parent star; the semi-major axis of the outermost planet is 1/12 the distance from Earth to the Sun. The radial velocity method could not be used to confirm the existence of planets due to the star's faintness. The Kepler-80b and Kepler 80c were initially confirmed through the transit-timing variation method. Two of the three other candidates were validated in February 2014.[3][8][9] The innermost planet was validated in 2016.[10]

The Kepler-80 planetary system[3][6][11][12][13]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
f 0.0175 ± 0.0002 0.98678730 ± 0.00000006 ~0 86.50 +2.36
−2.59
°
1.21 +0.06
−0.05
 R🜨
d 6.75 +0.69
−0.51
 M🜨
0.0372 ± 0.0005 3.0722 +0.00006
−0.00004
~0 88.35 +1.12
−1.51
°
1.53 +0.09
−0.07
 R🜨
e 4.13 +0.81
−0.95
 M🜨
0.0491 ± 0.0007 4.6449 +0.00020
−0.00019
~0 88.79 +0.84
−1.07
°
1.60 +0.08
−0.07
 R🜨
b 6.93 +1.05
−0.070
 M🜨
0.0658 ± 0.0009 7.0525 +0.00020
−0.00022
~0 89.34 +0.46
−0.62
°
2.67 ± 0.10 R🜨
c 6.74 +1.23
−0.86
 M🜨
0.0792 ± 0.0011 9.52355 +0.00041
−0.00029
~0 89.33 +0.47
−0.57
°
2.74 +0.12
−0.10
 R🜨
g 0.142 +0.037
−0.051
14.64558 ± 0.00012 89.35 +0.47
−0.98
°
1.13 ± 0.14 R🜨

Orbital resonance

Kepler-80 d, e, b, c and g have orbits locked in a resonance. While their periods are in a ~ 1.000: 1.512: 2.296: 3.100: 4.767 ratio, in a frame of reference that rotates with the conjunctions this reduces to a ratio of 4:6:9:12:18. Conjunctions of d and e, e and b, b and c, and c and g occur at relative intervals of 2:3:6:6 in a pattern that repeats about every 191 days. Librations of possible three-body resonances have amplitudes of only about 3 degrees, and modeling indicates the resonant system is stable to perturbations. Triple conjunctions do not occur.[6][11]

References

  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ "Kepler-80". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 10 January 2017.
  3. ^ a b c "OASIS". Abstractsonline.com. Retrieved 2012-11-22.
  4. ^ McQuillan, A.; Mazeh, T.; Aigrain, S. (2013). "Stellar Rotation Periods of The Kepler objects of Interest: A Dearth of Close-In Planets Around Fast Rotators". The Astrophysical Journal Letters. 775 (1). L11. arXiv:1308.1845. Bibcode:2013ApJ...775L..11M. doi:10.1088/2041-8205/775/1/L11.
  5. ^ Xie, J.-W. (2013). "Transit timing variation of near-resonance planetary pairs: confirmation of 12 multiple-planet systems". Astrophysical Journal Supplement Series. 208 (2): 22. arXiv:1208.3312. Bibcode:2013ApJS..208...22X. doi:10.1088/0067-0049/208/2/22.
  6. ^ a b c Shallue, C. J.; Vanderburg, A. (2017). "Identifying Exoplanets With Deep Learning: A Five Planet Resonant Chain Around Kepler-80 And An Eighth Planet Around Kepler-90" (PDF). The Astrophysical Journal. arXiv:1712.05044. Bibcode:2018AJ....155...94S. doi:10.3847/1538-3881/aa9e09. Retrieved 2017-12-15.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  7. ^ St. Fleur, Nicholas (14 December 2017). "An 8th Planet Is Found Orbiting a Distant Star, With A.I.'s Help". The New York Times. Retrieved 15 December 2017.
  8. ^ "Tiny Alien Solar System Discovery Explained (Infographic) | KOI-500 Exoplanets, Kepler". Space.com. Retrieved 2012-11-22.
  9. ^ http://www.nasa.gov/sites/default/files/files/arXivValidationMultisII.pdf
  10. ^ http://www.nasa.gov/press-release/nasas-kepler-mission-announces-largest-collection-of-planets-ever-discovered
  11. ^ a b MacDonald, Mariah G.; Ragozzine, Darin; Fabrycky, Daniel C.; Ford, Eric B.; Holman, Matthew J.; Isaacson, Howard T.; Lissauer, Jack J.; Lopez, Eric D.; Mazeh, Tsevi (2016-01-01). "A Dynamical Analysis of the Kepler-80 System of Five Transiting Planets". The Astronomical Journal. 152 (4): 105. arXiv:1607.07540. Bibcode:2016AJ....152..105M. doi:10.3847/0004-6256/152/4/105.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  12. ^ "Kepler-80 g". NASA Exoplanet Archive. Retrieved 14 December 2017.
  13. ^ "Kepler-80". NASA Exoplanet Archive. Retrieved May 9, 2018.