Kepler-148 d
Astrophysical Synthesis & Habitability Characterization
Kepler-148 d is a confirmed gas giant exoplanet orbiting the star Kepler-148, located approximately 2580.4 light-years (791.16 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.9652% across the stellar disk), this world measures 8.68 Earth radii (0.77 Jupiter radii) and has a measured mass of 56.3 Earth masses (0.18 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.47 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.75 g⊕ (7.35 m/s²), and an escape velocity of 28.5 km/s.
In its orbital architecture around Kepler-148, Kepler-148 d completes one full revolution every 51.847 Earth days at a semi-major axis of 0.2607 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 54.7 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 413 K (+140°C / +284°F) and receiving 6.53 S⊕ (~8,890 W/m²), Kepler-148 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-148 is classified as a stellar host with an effective photospheric temperature of 5,172 K, a radius of 0.81 R☉, a mass of 0.86 M☉, an estimated bolometric luminosity of 0.421 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.68 Gyr and a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, Kepler-148 shines at apparent V-band magnitude 15.398 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-148 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-148 d sharing its stellar neighborhood alongside Kepler-148 b, Kepler-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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-148 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,172 K |
| Stellar Radius | 0.8100 R☉ |
| Stellar Mass | 0.8600 M☉ |
| Bolometric Luminosity | 0.421 L☉ |
| Metallicity [Fe/H] | 0.070 dex |
| Stellar Age | 4.680 Gyr |
| Apparent Magnitude | V: 15.398 · G: 15.336 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.260700 AU |
| Orbital Period | 51.847 days |
| Mean Orbital Velocity | 54.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4500° |
| Mean Bulk Density | 0.47 g/cm³ (28.5 km/s vesc) |
| Insolation Flux | 6.5320 S⊕ (~8,890 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2580.400 LY (791.163 pc) |