HD 16141 b
Astrophysical Synthesis & Habitability Characterization
HD 16141 b is a confirmed gas giant exoplanet orbiting the star HD 16141, located approximately 123.2 light-years (37.79 parsecs) from the Solar System. First announced in 2000 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 10.9 Earth radii (0.97 Jupiter radii) and has a measured mass of 82.636 Earth masses (0.26 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.35 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 30.8 km/s.
In its orbital architecture around HD 16141, HD 16141 b completes one full revolution every 75.523 Earth days at a semi-major axis of 0.36 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 51.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.25, swinging from 0.27 AU at periapsis out to 0.45 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 563 K (+290°C / +554°F) and receiving 17.91 S⊕ (~24,369 W/m²), HD 16141 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 16141 is classified as a solar-type yellow star of spectral type G5 IV with an effective photospheric temperature of 5,757 K, a radius of 1.48 R☉, a mass of 1.11 M☉, an estimated bolometric luminosity of 2.159 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.51 Gyr and a metallicity of [Fe/H] = 0.13 dex (metal-rich relative to the Sun). From Earth, HD 16141 shines at apparent V-band magnitude 6.834 (accessible to binoculars and small amateur telescopes) in the Southern 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 16141 |
| Spectral Type | G5 IV |
| Effective Temp (Teff) | 5,757 K |
| Stellar Radius | 1.4800 R☉ |
| Stellar Mass | 1.1100 M☉ |
| Bolometric Luminosity | 2.159 L☉ |
| Metallicity [Fe/H] | 0.130 dex |
| Stellar Age | 7.510 Gyr |
| Apparent Magnitude | V: 6.834 · G: 6.658 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.360000 AU |
| Orbital Period | 75.523 days |
| Mean Orbital Velocity | 51.9 km/s |
| Orbital Eccentricity (e) | 0.25000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.35 g/cm³ (30.8 km/s vesc) |
| Insolation Flux | 17.9052 S⊕ (~24,369 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 123.200 LY (37.786 pc) |