Kepler-89
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 49m 19.9345s[1] |
| Declination | +41° 53′ 28.0059″[1] |
| Apparent magnitude (V) | 12.4[2] |
| Characteristics | |
| Spectral type | F8 V |
| Astrometry | |
| Proper motion (μ) | RA: 1.966±0.038 mas/yr Dec.: 1.365±0.044 mas/yr |
| Parallax (π) | 2.0676 ± 0.0216[1] mas |
| Distance | 1,580 ± 20 ly (484 ± 5 pc) |
| Details[3] | |
| Mass | 1.25+0.03 −0.04 M☉ |
| Radius | 1.61+0.11 −0.12 R☉ |
| Surface gravity (log g) | 4.123 ± 0.055 cgs |
| Temperature | 6116 K |
| Metallicity [Fe/H] | −0.01 ± 0.04 dex |
| Rotational velocity (v sin i) | 7.33 ± 0.32 km/s |
| Age | 3.9+0.3 −0.2 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| KIC | data |
Kepler-89 is a star with four confirmed planets. Kepler-89 is a possible wide binary star.[5]
Planetary system[]
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 , indicating that Kepler-89d is slightly larger and more massive than Saturn.[6] In October 2013, other three planets were confirmed with 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]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| <10.5 M
|