Kepler-1018 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1018 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1018, located approximately 3294.2 light-years (1010.01 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0722% across the stellar disk), this world measures 2.58 Earth radii and has a measured mass of 7.18 Earth masses. Combining its mass and radius yields a mean bulk density of 2.31 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 18.7 km/s.
In its orbital architecture around Kepler-1018, Kepler-1018 b completes one full revolution every 49.101 Earth days at a semi-major axis of 0.253 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 56.1 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 498 K (+225°C / +437°F) and receiving 12.10 S⊕ (~16,465 W/m²), Kepler-1018 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1018 is classified as a stellar host with an effective photospheric temperature of 5,518 K, a radius of 0.88 R☉, a mass of 0.91 M☉, an estimated bolometric luminosity of 0.644 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = -0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-1018 shines at apparent V-band magnitude 15.103 (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-1018 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,518 K |
| Stellar Radius | 0.8800 R☉ |
| Stellar Mass | 0.9100 M☉ |
| Bolometric Luminosity | 0.644 L☉ |
| Metallicity [Fe/H] | -0.050 dex |
| Stellar Age | 4.470 Gyr |
| Apparent Magnitude | V: 15.103 · G: 15.014 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.253000 AU |
| Orbital Period | 49.101 days |
| Mean Orbital Velocity | 56.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4300° |
| Mean Bulk Density | 2.31 g/cm³ (18.7 km/s vesc) |
| Insolation Flux | 12.0980 S⊕ (~16,465 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3294.200 LY (1010.010 pc) |