K2-365 b
Astrophysical Synthesis & Habitability Characterization
K2-365 b is a confirmed sub-neptune exoplanet orbiting the star K2-365, located approximately 610.6 light-years (187.22 parsecs) from the Solar System. First announced in 2022 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0643% across the stellar disk), this world measures 2.906 Earth radii and has a measured mass of 8.78 Earth masses. Combining its mass and radius yields a mean bulk density of 1.97 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.04 g⊕ (10.2 m/s²), and an escape velocity of 19.4 km/s.
In its orbital architecture around K2-365, K2-365 b completes one full revolution every 23.448 Earth days.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 2.906 R⊕, K2-365 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star K2-365 is classified as a stellar host with an effective photospheric temperature of 5,561 K, a radius of 1.051 R☉, a mass of 0.823 M☉, an estimated bolometric luminosity of 0.948 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.021 dex (near-solar heavy-element abundance). From Earth, K2-365 shines at apparent V-band magnitude 11.372 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | K2-365 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,561 K |
| Stellar Radius | 1.0510 R☉ |
| Stellar Mass | 0.8230 M☉ |
| Bolometric Luminosity | 0.948 L☉ |
| Metallicity [Fe/H] | -0.021 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 11.372 · G: 11.529 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 23.448 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.0039° |
| Mean Bulk Density | 1.97 g/cm³ (19.4 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 610.600 LY (187.222 pc) |