Kepler-1865 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1865 b is a confirmed super-earth exoplanet orbiting the star Kepler-1865, located approximately 3008 light-years (922.26 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0276% across the stellar disk), this world measures 1.577 Earth radii and has a measured mass of 3.11 Earth masses. Combining its mass and radius yields a mean bulk density of 4.37 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.25 g⊕ (12.26 m/s²), and an escape velocity of 15.7 km/s.
In its orbital architecture around Kepler-1865, Kepler-1865 b completes one full revolution every 2.524 Earth days at a semi-major axis of 0.0344 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 148.3 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 1203 K (+930°C / +1706°F) and receiving 495.14 S⊕ (~673,886 W/m²), Kepler-1865 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1865 is classified as a stellar host with an effective photospheric temperature of 5,420 K, a radius of 0.871 R☉, a mass of 0.849 M☉, an estimated bolometric luminosity of 0.587 L☉. Stellar evolution modeling indicates an estimated stellar age of 11.6 Gyr and a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, Kepler-1865 shines at apparent V-band magnitude 15.468 (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-1865 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,420 K |
| Stellar Radius | 0.8710 R☉ |
| Stellar Mass | 0.8490 M☉ |
| Bolometric Luminosity | 0.587 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | 11.600 Gyr |
| Apparent Magnitude | V: 15.468 · G: 15.543 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.034400 AU |
| Orbital Period | 2.524 days |
| Mean Orbital Velocity | 148.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.7300° |
| Mean Bulk Density | 4.37 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 495.1400 S⊕ (~673,886 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3008.000 LY (922.255 pc) |