Kepler-88
Observation data
Epoch J2000      Equinox J2000
Constellation Lyra
Right ascension 19h 24m 35.54310s[1]
Declination +40° 40′ 09.8099″[1]
Apparent magnitude (V) 13.257[2]
Characteristics
Spectral type G6V[3]
Astrometry
Radial velocity (Rv)−19.51±1.63[1] km/s
Proper motion (μ) RA: 1.150(11) mas/yr[1]
Dec.: 4.956(15) mas/yr[1]
Parallax (π)2.6495 ± 0.0109 mas[1]
Distance1,231 ± 5 ly
(377 ± 2 pc)
Absolute magnitude (MV)5.46±0.16[4]
Details
Mass0.990±0.023[5] M☉
Radius0.897±0.016[5] R☉
Luminosity0.598+0.079
−0.070[4] L☉
Surface gravity (log g)4.528+0.025
−0.019[4] cgs
Temperature5466±60[5] K
Metallicity [Fe/H]+0.27±0.06[5] dex
Rotation30.689±0.383 days[6]
Age1.9±1.6[5] Gyr
Other designations
Kepler-88, KOI-142, KIC 5446285, TIC 122712595, 2MASS J19243554+4040098[2]
Database references
SIMBADdata
KICdata

Kepler-88 is a G-type star 1,230 light-years (380 parsecs) away in the constellation of Lyra, with three confirmed exoplanets.[5] SIMBAD lists a subgiant spectral type of G8IV,[2] while other sources give it a main sequence spectral type of G6V.[3] The latter is more consistent with its properties (it is less luminous than the Sun).

Planetary system

In April 2012, scientists discovered that a Kepler candidate known as KOI-142.01 (Kepler-88b) exhibited very significant transit-timing variations caused by a non-transiting planet.[4] The timing variations were large enough to cause changes to the transit durations of Kepler-88b as well. Large transit-timing variations helped to put tight constraints on the masses of both planets. The non-transiting planet, Kepler-88c, was further confirmed through the radial velocity method in November 2013.[3]

Kepler-88b is the innermost planet in the system and is Neptune-sized but almost half as massive. Kepler 88c is about 67% as massive as Jupiter, but its radius is not known due to not transiting the star.[5]

Kepler-88d orbits its star every four years, and its orbit is not circular, but elliptical. At three times the mass of Jupiter, it is the most massive planet known in the system. It was discovered based on six years of radial velocity (RV) follow-up from the W. M. Keck Observatory HIRES spectrograph.[5]

The Kepler-88 planetary system[5]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b 9.5±1.1 M🜨 0.098 10.91647±0.00014 0.05561±0.00013 90.97±0.12° 3.438±0.075 R🜨
c 0.674±0.016 MJ 0.15525 22.26492±0.00067 0.05724±0.00045 93.15±0.68° —
d ≥3.05±0.16 MJ 2.45±0.02 1403±14 0.41±0.03 — —

References

  1. ^ a b c d e 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. ^ a b c "Kepler-88". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 19 February 2024.
  3. ^ a b c Barros, S. C. C.; Díaz, R. F.; et al. (January 2014). "SOPHIE velocimetry of Kepler transit candidates. X. KOI-142 c: first radial velocity confirmation of a non-transiting exoplanet discovered by transit timing". Astronomy & Astrophysics. 561: L1. arXiv:1311.4335. Bibcode:2014A&A...561L...1B. doi:10.1051/0004-6361/201323067.
  4. ^ a b c d Nesvorný, David; Kipping, David; Terrell, Dirk; Hartman, Joel; Bakos, Gáspár Á; Buchhave, Lars A (2013). "KOI-142, the King of Transit Variations, is a Pair of Planets Near the 2:1 Resonance". The Astrophysical Journal. 777 (1): 3. arXiv:1304.4283. Bibcode:2013ApJ...777....3N. doi:10.1088/0004-637X/777/1/3. S2CID 59933168.
  5. ^ a b c d e f g h i Weiss, Lauren M.; Fabrycky, Daniel C.; Agol, Eric; Mills, Sean M.; Howard, Andrew W.; Isaacson, Howard; Petigura, Erik A.; Fulton, Benjamin; Hirsch, Lea; Sinukoff, Evan (2020-04-29). "The Discovery of the Long-Period, Eccentric Planet Kepler-88 d and System Characterization with Radial Velocities and Photodynamical Analysis" (PDF). The Astronomical Journal. 159 (5): 242. arXiv:1909.02427. Bibcode:2020AJ....159..242W. doi:10.3847/1538-3881/ab88ca. ISSN 1538-3881. S2CID 202539420.
  6. ^ 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. S2CID 118557681.
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