Kepler-1089 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1089 b is a confirmed super-earth exoplanet orbiting the star Kepler-1089, located approximately 845.8 light-years (259.33 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1172% across the stellar disk), this world measures 1.83 Earth radii and has a measured mass of 4.01 Earth masses. Combining its mass and radius yields a mean bulk density of 3.61 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.2 g⊕ (11.77 m/s²), and an escape velocity of 16.6 km/s.
In its orbital architecture around Kepler-1089, Kepler-1089 b completes one full revolution every 5.132 Earth days at a semi-major axis of 0.0497 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 105.3 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 584 K (+311°C / +592°F) and receiving 26.27 S⊕ (~35,748 W/m²), Kepler-1089 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1089 is classified as a stellar host with an effective photospheric temperature of 3,753 K, a radius of 0.49 R☉, a mass of 0.52 M☉, an estimated bolometric luminosity of 0.043 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.72 Gyr and a metallicity of [Fe/H] = -0.09 dex (near-solar heavy-element abundance). From Earth, Kepler-1089 shines at apparent V-band magnitude 16.233 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-1089 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,753 K |
| Stellar Radius | 0.4900 R☉ |
| Stellar Mass | 0.5200 M☉ |
| Bolometric Luminosity | 0.043 L☉ |
| Metallicity [Fe/H] | -0.090 dex |
| Stellar Age | 3.720 Gyr |
| Apparent Magnitude | V: 16.233 · G: 15.598 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.049700 AU |
| Orbital Period | 5.132 days |
| Mean Orbital Velocity | 105.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.5400° |
| Mean Bulk Density | 3.61 g/cm³ (16.6 km/s vesc) |
| Insolation Flux | 26.2660 S⊕ (~35,748 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 845.800 LY (259.328 pc) |