K2-373 b
Astrophysical Synthesis & Habitability Characterization
K2-373 b is a confirmed sub-neptune exoplanet orbiting the star K2-373, located approximately 748.7 light-years (229.57 parsecs) from the Solar System. First announced in 2022 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0162% across the stellar disk), this world measures 2.061 Earth radii and has a measured mass of 4.9 Earth masses. Combining its mass and radius yields a mean bulk density of 3.09 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.15 g⊕ (11.28 m/s²), and an escape velocity of 17.2 km/s.
In its orbital architecture around K2-373, K2-373 b completes one full revolution every 11.021 Earth days.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for K2-373 b place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star K2-373 is classified as a stellar host with an effective photospheric temperature of 6,138 K, a radius of 1.486 R☉, a mass of 1.158 M☉, an estimated bolometric luminosity of 2.812 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.049 dex (near-solar heavy-element abundance). From Earth, K2-373 shines at apparent V-band magnitude 10.47 (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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | K2-373 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,138 K |
| Stellar Radius | 1.4860 R☉ |
| Stellar Mass | 1.1580 M☉ |
| Bolometric Luminosity | 2.812 L☉ |
| Metallicity [Fe/H] | 0.049 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 10.470 · G: 10.424 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 11.021 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 3.09 g/cm³ (17.2 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 748.700 LY (229.567 pc) |