K2-148 d
Astrophysical Synthesis & Habitability Characterization
K2-148 d is a confirmed super-earth exoplanet orbiting the star K2-148, located approximately 405.9 light-years (124.46 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0566% across the stellar disk), this world measures 1.64 Earth radii and has a measured mass of 3.33 Earth masses. Combining its mass and radius yields a mean bulk density of 4.16 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 15.9 km/s.
In its orbital architecture around K2-148, K2-148 d completes one full revolution every 9.758 Earth days at a semi-major axis of 0.0774 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 86.3 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 562 K (+289°C / +552°F) and receiving 16.80 S⊕ (~22,865 W/m²), K2-148 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-148 is classified as a stellar host with an effective photospheric temperature of 4,079 K, a radius of 0.632 R☉, a mass of 0.65 M☉, an estimated bolometric luminosity of 0.099 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.11 dex (metal-poor relative to the Sun). From Earth, K2-148 shines at apparent V-band magnitude 13.627 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The K2-148 system is a multi-planet architecture hosting 3 confirmed worlds, with K2-148 d sharing its stellar neighborhood alongside K2-148 b, K2-148 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 | K2-148 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,079 K |
| Stellar Radius | 0.6320 R☉ |
| Stellar Mass | 0.6500 M☉ |
| Bolometric Luminosity | 0.099 L☉ |
| Metallicity [Fe/H] | -0.110 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 13.627 · G: 13.060 |
| System Architecture | 2 Stars, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.077400 AU |
| Orbital Period | 9.758 days |
| Mean Orbital Velocity | 86.3 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.16 g/cm³ (15.9 km/s vesc) |
| Insolation Flux | 16.8000 S⊕ (~22,865 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 405.900 LY (124.458 pc) |