K2-282 b
Astrophysical Synthesis & Habitability Characterization
K2-282 b is a confirmed sub-neptune exoplanet orbiting the star K2-282, located approximately 1618.7 light-years (496.29 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0525% across the stellar disk), this world measures 2.5 Earth radii and has a measured mass of 6.8 Earth masses. Combining its mass and radius yields a mean bulk density of 2.4 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.09 g⊕ (10.69 m/s²), and an escape velocity of 18.4 km/s.
In its orbital architecture around K2-282, K2-282 b completes one full revolution every 4.17 Earth days at a semi-major axis of 0.0499 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 130.2 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1057 K (+784°C / +1443°F) and receiving 245.00 S⊕ (~333,446 W/m²), K2-282 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-282 is classified as a stellar host with an effective photospheric temperature of 5,499 K, a radius of 1 R☉, a mass of 0.94 M☉, an estimated bolometric luminosity of 0.82 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.23 dex (metal-poor relative to the Sun). From Earth, K2-282 shines at apparent V-band magnitude 14.21 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The K2-282 system is a multi-planet architecture hosting 2 confirmed worlds, with K2-282 b sharing its stellar neighborhood alongside EPIC 220554210 c.
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 | K2-282 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,499 K |
| Stellar Radius | 1.0000 R☉ |
| Stellar Mass | 0.9400 M☉ |
| Bolometric Luminosity | 0.82 L☉ |
| Metallicity [Fe/H] | -0.230 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 14.210 · G: 13.818 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.049900 AU |
| Orbital Period | 4.17 days |
| Mean Orbital Velocity | 130.2 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 90.1000° |
| Mean Bulk Density | 2.4 g/cm³ (18.4 km/s vesc) |
| Insolation Flux | 245.0004 S⊕ (~333,446 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1618.700 LY (496.289 pc) |