Kepler-89 is a star with four confirmed planets. Kepler-89 is a possible wide binary star.[5]

Kepler-89
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 49m 19.9343s[1]
Declination +41° 53′ 28.006″[1]
Apparent magnitude (V) 12.4[2]
Characteristics
Spectral type F8 V
Astrometry
Proper motion (μ) RA: 2.063(10) mas/yr[1]
Dec.: 1.337(11) mas/yr[1]
Parallax (π)2.1069 ± 0.0086 mas[1]
Distance1,548 ± 6 ly
(475 ± 2 pc)
Details[3]
Mass1.25+0.03
−0.04
 M
Radius1.61+0.11
−0.12
 R
Surface gravity (log g)4.123 ± 0.055 cgs
Temperature6116 K
Metallicity [Fe/H]−0.01 ± 0.04 dex
Rotational velocity (v sin i)7.33 ± 0.32 km/s
Age3.9+0.3
−0.2
 Gyr
Other designations
Gaia DR2 2076970047474270208, KOI-94, KIC 6462863, 2MASS J19491993+4153280[4]
Database references
SIMBADdata
KICdata

Planetary system

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The discovery of four planets orbiting the star was announced October 2012 by analyzing data gathered by Kepler space telescope.[3] Follow-up radial velocity measurements confirmed the existence of Kepler-89d, indicating that Kepler-89d is slightly larger and more massive than Saturn.[6] In October 2013, other three planets were confirmed with Kepler-89c and Kepler-89e getting reasonable mass constraints. Transit-timing variations of the outermost planet suggest that additional planets or minor bodies are present in the system.[7]

In 2012, a partial transit of the second outermost planet by the outermost planet was reported. This was the first time a planet-planet transit in front of the star was detected.[8][3] This allowed to determine the mutual inclination of the planets d and e to be 1.15°.[7]

Stephen R. Kane did a dynamical analysis of the Kepler-89 system that demonstrated that planets c and d, although close to the 2:1 secular resonance, are not permanently in a 2:1 resonance configuration.[9]

The Kepler-89 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b <10.5 M🜨 0.05 3.7 89.3° 0.13 RJ
c 7.3-11.8 M🜨 0.099 10.4 <0.1 88.36° 0.31 RJ
d 0.33±0.034 MJ 0.165 22.3 <0.1 89.871° 0.83 RJ
e 11.9-15.5 M🜨 0.298 54.3 <0.1 89.76° 0.49 RJ

References

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  1. ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ "Planet Kepler-89 b". Extrasolar Planets Encyclopaedia. Retrieved 26 April 2018.
  3. ^ a b c Hirano, Teruyuki; et al. (2012). "Planet-Planet Eclipse and the Rossiter-McLaughlin Effect of a Multiple Transiting System: Joint Analysis of the Subaru Spectroscopy and the Kepler Photometry". The Astrophysical Journal. 759 (2). L36. arXiv:1209.4362. Bibcode:2012ApJ...759L..36H. doi:10.1088/2041-8205/759/2/L36.
  4. ^ "Kepler-89". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-08-07.
  5. ^ Takahashi, Yasuhiro H.; Norio Narita; Teruyuki Hirano; Masayuki Kuzuhara; et al. (2013). "A Discovery of a Candidate Companion to a Transiting System KOI-94: A Direct Imaging Study for a Possibility of a False Positive". arXiv:1309.2559 [astro-ph.EP].
  6. ^ Weiss, Lauren M.; et al. (2013). "The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident Flux". The Astrophysical Journal. 768 (1). 14. arXiv:1303.2150. Bibcode:2013ApJ...768...14W. doi:10.1088/0004-637X/768/1/14.
  7. ^ a b Masuda, Kento; et al. (2013). "Characterization of the KOI-94 System with Transit Timing Variation Analysis: Implication for the Planet-Planet Eclipse". The Astrophysical Journal. 778 (2). 185. arXiv:1310.5771. Bibcode:2013ApJ...778..185M. doi:10.1088/0004-637X/778/2/185.
  8. ^ "First ever discovery of planet-planet eclipse | UTokyo Research". u-tokyo.ac.jp. Archived from the original on 2013-11-04. Retrieved 2014-01-20.
  9. ^ Kane, Stephen R. (2019). "Orbital Stability and Precession Effects in the Kepler-89 System". The Astronomical Journal. 158 (2). 72. arXiv:1906.07193. Bibcode:2019AJ....158...72K. doi:10.3847/1538-3881/ab2a09.