Kepler-43 b
Astrophysical Synthesis & Habitability Characterization
Kepler-43 b is a confirmed gas giant exoplanet orbiting the star Kepler-43, located approximately 3280.6 light-years (1005.84 parsecs) from the Solar System. First announced in 2011 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.7783% across the stellar disk), this world measures 13.664 Earth radii (1.22 Jupiter radii) and has a measured mass of 1026.591 Earth masses (3.23 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.22 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 5.5 g⊕ (53.94 m/s²), and an escape velocity of 97 km/s.
In its orbital architecture around Kepler-43, Kepler-43 b completes one full revolution every 3.024 Earth days at a semi-major axis of 0.046 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 165.5 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.017 (ranging from 0.0452 AU at periapsis to 0.0468 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1620 K (+1347°C / +2457°F) and receiving 1,138.12 S⊕ (~1,548,975 W/m²), Kepler-43 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-43 is classified as a warm F-type star of spectral type F8 V with an effective photospheric temperature of 6,041 K, a radius of 1.42 R☉, a mass of 1.32 M☉, an estimated bolometric luminosity of 2.409 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.69 Gyr and a metallicity of [Fe/H] = 0.33 dex (metal-rich relative to the Sun). From Earth, Kepler-43 shines at apparent V-band magnitude 13.986 (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-43 |
| Spectral Type | F8 V |
| Effective Temp (Teff) | 6,041 K |
| Stellar Radius | 1.4200 R☉ |
| Stellar Mass | 1.3200 M☉ |
| Bolometric Luminosity | 2.409 L☉ |
| Metallicity [Fe/H] | 0.330 dex |
| Stellar Age | 0.690 Gyr |
| Apparent Magnitude | V: 13.986 · G: 13.889 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.046000 AU |
| Orbital Period | 3.024 days |
| Mean Orbital Velocity | 165.5 km/s |
| Orbital Eccentricity (e) | 0.01700 |
| Orbital Inclination (i) | 84.6460° |
| Mean Bulk Density | 2.22 g/cm³ (97 km/s vesc) |
| Insolation Flux | 1138.1150 S⊕ (~1,548,975 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3280.600 LY (1005.840 pc) |