HD 238914 b
Astrophysical Synthesis & Habitability Characterization
HD 238914 b is a confirmed gas giant exoplanet orbiting the star HD 238914, located approximately 1694.2 light-years (519.45 parsecs) from the Solar System. First announced in 2018 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.8 Earth radii (1.14 Jupiter radii) and has a measured mass of 1906.98 Earth masses (6 Jupiter masses). Combining its mass and radius yields a mean bulk density of 5.01 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 11.64 g⊕ (114.15 m/s²), and an escape velocity of 136.5 km/s.
In its orbital architecture around HD 238914, HD 238914 b completes one full revolution every 4100 Earth days (11.23Julian years) at a semi-major axis of 5.7 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 15.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.56, swinging from 2.508 AU at periapsis out to 8.892 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.800 R⊕, HD 238914 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 HD 238914 is classified as an orange K-type star of spectral type K7 with an effective photospheric temperature of 4,769 K, a radius of 12.73 R☉, a mass of 1.47 M☉, an estimated bolometric luminosity of 75.207 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.25 dex (metal-poor relative to the Sun). From Earth, HD 238914 shines at apparent V-band magnitude 8.77 (accessible to binoculars and small amateur telescopes) 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 238914 |
| Spectral Type | K7 |
| Effective Temp (Teff) | 4,769 K |
| Stellar Radius | 12.7300 R☉ |
| Stellar Mass | 1.4700 M☉ |
| Bolometric Luminosity | 75.207 L☉ |
| Metallicity [Fe/H] | -0.250 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 8.770 · G: 8.497 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 5.700000 AU |
| Orbital Period | 4100 days |
| Mean Orbital Velocity | 15.1 km/s |
| Orbital Eccentricity (e) | 0.56000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 5.01 g/cm³ (136.5 km/s vesc) |
| Insolation Flux | 2.1790 S⊕ (~2,966 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1694.200 LY (519.452 pc) |