Kepler-1322 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1322 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-1322, located approximately 4404.1 light-years (1350.32 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0604% across the stellar disk), this world measures 2.155 Earth radii and has a measured mass of 5.29 Earth masses. Combining its mass and radius yields a mean bulk density of 2.91 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.14 g⊕ (11.18 m/s²), and an escape velocity of 17.5 km/s.
In its orbital architecture around Kepler-1322, Kepler-1322 c completes one full revolution every 6.46 Earth days at a semi-major axis of 0.0652 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 109.8 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 883 K (+610°C / +1130°F) and receiving 144.06 S⊕ (~196,066 W/m²), Kepler-1322 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1322 is classified as a stellar host with an effective photospheric temperature of 5,704 K, a radius of 0.804 R☉, a mass of 0.897 M☉, an estimated bolometric luminosity of 0.614 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.4 Gyr and a metallicity of [Fe/H] = -0.3 dex (metal-poor relative to the Sun). From Earth, Kepler-1322 shines at apparent V-band magnitude 15.876 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1322 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1322 c sharing its stellar neighborhood alongside Kepler-1322 b.
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-1322 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,704 K |
| Stellar Radius | 0.8040 R☉ |
| Stellar Mass | 0.8970 M☉ |
| Bolometric Luminosity | 0.614 L☉ |
| Metallicity [Fe/H] | -0.300 dex |
| Stellar Age | 0.400 Gyr |
| Apparent Magnitude | V: 15.876 · G: 15.775 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.065200 AU |
| Orbital Period | 6.46 days |
| Mean Orbital Velocity | 109.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.8200° |
| Mean Bulk Density | 2.91 g/cm³ (17.5 km/s vesc) |
| Insolation Flux | 144.0600 S⊕ (~196,066 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 4404.100 LY (1350.320 pc) |