Kepler-1389 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1389 b is a confirmed super-earth exoplanet orbiting the star Kepler-1389, located approximately 1621.3 light-years (497.09 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0481% across the stellar disk), this world measures 1.77 Earth radii and has a measured mass of 3.78 Earth masses. Combining its mass and radius yields a mean bulk density of 3.76 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 16.3 km/s.
In its orbital architecture around Kepler-1389, Kepler-1389 b completes one full revolution every 99.253 Earth days at a semi-major axis of 0.38249 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 41.9 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.
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 300 K (+27°C / +81°F) and an incident stellar irradiance of 1.87 S⊕ (~2,546 W/m²), Kepler-1389 b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star Kepler-1389 is classified as a stellar host with an effective photospheric temperature of 5,078 K, a radius of 0.74 R☉, a mass of 0.81 M☉, an estimated bolometric luminosity of 0.327 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.09 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-1389 shines at apparent V-band magnitude 14.896 (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-1389 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,078 K |
| Stellar Radius | 0.7400 R☉ |
| Stellar Mass | 0.8100 M☉ |
| Bolometric Luminosity | 0.327 L☉ |
| Metallicity [Fe/H] | -0.140 dex |
| Stellar Age | 2.090 Gyr |
| Apparent Magnitude | V: 14.896 · G: 14.684 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.382490 AU |
| Orbital Period | 99.253 days |
| Mean Orbital Velocity | 41.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.7100° |
| Mean Bulk Density | 3.76 g/cm³ (16.3 km/s vesc) |
| Insolation Flux | 1.8710 S⊕ (~2,546 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 1621.300 LY (497.093 pc) |