Astronomy:Kepler-84

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Short description: Star in the constellation Cygnus
Kepler-84
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cygnus
Right ascension  01h 37m 40.87964s[1]
Declination +12° 04′ 42.1742″[1]
Characteristics
Spectral type G3[2]
Astrometry
Proper motion (μ) RA: −0.150 mas/yr
Dec.: −2.872 mas/yr
Parallax (π)0.6929 ± 0.7043 mas
Details
Mass1[2] M
Radius1.2 R
Temperature5,755[3] K
Metallicity [Fe/H]+0.09 ± 0.04[2] dex
Age4.9[4] Gyr
Other designations
Kepler-84, KOI-1589, Gaia DR2 2073776859551124992, KIC 5301750, 2MASS J19530049+4029458[1]
Database references
SIMBADdata
ARICNSdata

Kepler-84 is a Sun-like star 4,700 light-years from the Sun. It is a G-type star. The stellar radius measurement has a large uncertainty of 48% as in 2017, complicating the modelling of the star.[5] The Kepler-84 star has two suspected stellar companions. Four red dwarfs are few arcseconds away and at least one is probably gravitationally bound to Kepler-84.[6] Another (which is a background star with a probability 0.5%) is a yellow star of mass 0.855M on projected separations of 0.18±0.05″ or 0.26″ (213.6 AU).[7]

Planetary system

Kepler-84 is orbited by five known planets, four small gas giants and a Super-Earth. Planets Kepler-84b and Kepler-84c were confirmed in 2012[8] while the rest was confirmed in 2014.[9] To keep the known planetary system stable, no additional giant planets can be located within 7.4 AU from the parent stars.[10]

The Kepler-84 planetary system[11][12][13][14]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 0.126±0.038 MJ 0.083 8.725854±0.00006 0 88.24° 0.174±0.045 RJ
c 0.064±0.037 MJ 0.108 12.882525±0.000093 0 88.24° 0.184±0.047 RJ
d 0.052 4.224537±0.000042 0.123±0.024 RJ
e 0.181 27.434389±0.000224 0.232±0.044 RJ
f 0.25 44.552169±0.000812 0.196±0.038 RJ

References

  1. 1.0 1.1 1.2 "Kepler-84". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Kepler-84. 
  2. 2.0 2.1 2.2 Vidotto, A. A; Gregory, S. G; Jardine, M; Donati, J. F; Petit, P; Morin, J; Folsom, C. P; Bouvier, J et al. (2014). "Stellar magnetism: Empirical trends with age and rotation". Monthly Notices of the Royal Astronomical Society 441 (3): 2361. doi:10.1093/mnras/stu728. Bibcode2014MNRAS.441.2361V. https://eprints.usq.edu.au/25465/19/Vidotto_etal_MNRAS_v441_PV.pdf. 
  3. Gray, R. O; Corbally, C. J; Garrison, R. F; McFadden, M. T; Robinson, P. E (2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal 126 (4): 2048. doi:10.1086/378365. Bibcode2003AJ....126.2048G. 
  4. Melendez, Jorge; Dodds-Eden, Katie; Robles, Jose A (2006). "HD 98618: A Star Closely Resembling our Sun". The Astrophysical Journal 641 (2): L133–L136. doi:10.1086/503898. Bibcode2006ApJ...641L.133M. 
  5. Ramos, X. S.; Charalambous, C.; Benítez-Llambay, P.; Beaugé, C. (2017), "Planetary migration and the origin of the 2:1 and 3:2 (near)-resonant population of close-in exoplanets", Astronomy & Astrophysics 602: A101, doi:10.1051/0004-6361/201629642, Bibcode2017A&A...602A.101R 
  6. Hirsch, Lea A.; Ciardi, David R.; Howard, Andrew W.; Everett, Mark E.; Furlan, Elise; Saylors, Mindy; Horch, Elliott P.; Howell, Steve B. et al. (2017), "ASSESSING THE EFFECT OF STELLAR COMPANIONS FROM HIGH-RESOLUTION IMAGING OF Kepler OBJECTS OF INTEREST", The Astronomical Journal 153 (3): 117, doi:10.3847/1538-3881/153/3/117, Bibcode2017AJ....153..117H 
  7. Kraus, Adam L.; Ireland, Michael J.; Huber, Daniel; Mann, Andrew W.; Dupuy, Trent J. (2016), "The Impact of Stellar Multiplicity on Planetary Systems. I. The Ruinous Influence of Close Binary Companions", The Astronomical Journal 152 (1): 8, doi:10.3847/0004-6256/152/1/8, Bibcode2016AJ....152....8K 
  8. Xie, Ji-Wei (2012), "Transit Timing Variation of Near-Resonance Planetary Pairs: Confirmation of 12 Multiple-Planet Systems", The Astrophysical Journal Supplement Series 208 (2): 22, doi:10.1088/0067-0049/208/2/22, Bibcode2013ApJS..208...22X 
  9. openexoplanetcatalogue.com Kepler-84
  10. Becker, Juliette C.; Adams, Fred C. (2017), "Effects of Unseen Additional Planetary Perturbers on Compact Extrasolar Planetary Systems", Monthly Notices of the Royal Astronomical Society 468 (1): 549–563, doi:10.1093/mnras/stx461, Bibcode2017MNRAS.468..549B 
  11. Furlan, E.; Howell, S. B. (2017), "The densities of planets in multiple stellar systems", The Astronomical Journal 154 (2): 66, doi:10.3847/1538-3881/aa7b70, Bibcode2017AJ....154...66F 
  12. Planet Kepler-84 d at exoplanets.eu
  13. Planet Kepler-84 e at exoplanets.eu
  14. Planet Kepler-84 f at exoplanets.eu