Kepler-1946 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1946 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1946, located approximately 3268.5 light-years (1002.12 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0683% across the stellar disk), this world measures 2.488 Earth radii and has a measured mass of 6.75 Earth masses. Combining its mass and radius yields a mean bulk density of 2.42 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.09 g⊕ (10.69 m/s²), and an escape velocity of 18.4 km/s.
In its orbital architecture around Kepler-1946, Kepler-1946 b completes one full revolution every 3.035 Earth days at a semi-major axis of 0.0394 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 141.2 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 1143 K (+870°C / +1598°F) and receiving 403.53 S⊕ (~549,204 W/m²), Kepler-1946 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1946 is classified as a stellar host with an effective photospheric temperature of 5,505 K, a radius of 0.873 R☉, a mass of 0.887 M☉, an estimated bolometric luminosity of 0.628 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1946 shines at apparent V-band magnitude 15.508 (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-1946 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,505 K |
| Stellar Radius | 0.8730 R☉ |
| Stellar Mass | 0.8870 M☉ |
| Bolometric Luminosity | 0.628 L☉ |
| Metallicity [Fe/H] | -0.040 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 15.508 · G: 15.561 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.039400 AU |
| Orbital Period | 3.035 days |
| Mean Orbital Velocity | 141.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.1400° |
| Mean Bulk Density | 2.42 g/cm³ (18.4 km/s vesc) |
| Insolation Flux | 403.5300 S⊕ (~549,204 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3268.500 LY (1002.120 pc) |