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] |
Distance | 1,218 ± 10 ly (373 ± 3 pc) |
Details | |
Mass | 0.730 M☉ |
Radius | 0.678 R☉ |
Luminosity | 0.170 L☉ |
Temperature | 4540 K |
Metallicity [Fe/H] | -0.56 [3] dex |
Rotation | 25.567±0.252 days[4] |
Other designations | |
Database references | |
SIMBAD | data |
KIC | data |
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]
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
- ^ 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.
- ^ "Kepler-80". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 10 January 2017.
- ^ a b c "OASIS". Abstractsonline.com. Retrieved 2012-11-22.
- ^ 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.
- ^ 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.
- ^ 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) - ^ 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.
- ^ "Tiny Alien Solar System Discovery Explained (Infographic) | KOI-500 Exoplanets, Kepler". Space.com. Retrieved 2012-11-22.
- ^ http://www.nasa.gov/sites/default/files/files/arXivValidationMultisII.pdf
- ^ http://www.nasa.gov/press-release/nasas-kepler-mission-announces-largest-collection-of-planets-ever-discovered
- ^ 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) - ^ "Kepler-80 g". NASA Exoplanet Archive. Retrieved 14 December 2017.
- ^ "Kepler-80". NASA Exoplanet Archive. Retrieved May 9, 2018.