HD 141399 b
Astrophysical Synthesis & Habitability Characterization
HD 141399 b is a confirmed gas giant exoplanet orbiting the star HD 141399, located approximately 120.7 light-years (37.02 parsecs) from the Solar System. First announced in 2014 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14.3 Earth radii (1.28 Jupiter radii) and has a measured mass of 143.341 Earth masses (0.45 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.27 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.7 g⊕ (6.86 m/s²), and an escape velocity of 35.4 km/s.
In its orbital architecture around HD 141399, HD 141399 b completes one full revolution every 94.44 Earth days at a semi-major axis of 0.415 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 47.8 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.04 (ranging from 0.3984 AU at periapsis to 0.4316 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 494 K (+221°C / +430°F) and receiving 9.23 S⊕ (~12,565 W/m²), HD 141399 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 141399 is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 5,600 K, a radius of 1.3872 R☉, a mass of 1.07 M☉, an estimated bolometric luminosity of 1.698 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.35 dex (metal-rich relative to the Sun). From Earth, HD 141399 shines at apparent V-band magnitude 7.209 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 141399 system is a multi-planet architecture hosting 4 confirmed worlds, with HD 141399 b sharing its stellar neighborhood alongside HD 141399 c, HD 141399 d, HD 141399 e.
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 141399 |
| Spectral Type | K0 |
| Effective Temp (Teff) | 5,600 K |
| Stellar Radius | 1.3872 R☉ |
| Stellar Mass | 1.0700 M☉ |
| Bolometric Luminosity | 1.698 L☉ |
| Metallicity [Fe/H] | 0.350 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 7.209 · G: 7.009 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.415000 AU |
| Orbital Period | 94.44 days |
| Mean Orbital Velocity | 47.8 km/s |
| Orbital Eccentricity (e) | 0.04000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.27 g/cm³ (35.4 km/s vesc) |
| Insolation Flux | 9.2321 S⊕ (~12,565 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 120.700 LY (37.017 pc) |