HD 163607 b
Astrophysical Synthesis & Habitability Characterization
HD 163607 b is a confirmed gas giant exoplanet orbiting the star HD 163607, located approximately 221.1 light-years (67.79 parsecs) from the Solar System. First announced in 2012 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 13.9 Earth radii (1.24 Jupiter radii) and has a measured mass of 249.052 Earth masses (0.78 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.51 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 47.3 km/s.
In its orbital architecture around HD 163607, HD 163607 b completes one full revolution every 75.22 Earth days at a semi-major axis of 0.362 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 52.4 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.7441, swinging from 0.0926 AU at periapsis out to 0.6314 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 587 K (+314°C / +597°F) and receiving 20.07 S⊕ (~27,317 W/m²), HD 163607 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 163607 is classified as a solar-type yellow star of spectral type G5 with an effective photospheric temperature of 5,522 K, a radius of 1.76 R☉, a mass of 1.12 M☉, an estimated bolometric luminosity of 2.584 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.6 Gyr and a metallicity of [Fe/H] = 0.21 dex (metal-rich relative to the Sun). From Earth, HD 163607 shines at apparent V-band magnitude 8 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 163607 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 163607 b sharing its stellar neighborhood alongside HD 163607 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 163607 |
| Spectral Type | G5 |
| Effective Temp (Teff) | 5,522 K |
| Stellar Radius | 1.7600 R☉ |
| Stellar Mass | 1.1200 M☉ |
| Bolometric Luminosity | 2.584 L☉ |
| Metallicity [Fe/H] | 0.210 dex |
| Stellar Age | 8.600 Gyr |
| Apparent Magnitude | V: 8.000 · G: 7.813 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.362000 AU |
| Orbital Period | 75.22 days |
| Mean Orbital Velocity | 52.4 km/s |
| Orbital Eccentricity (e) | 0.74410 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.51 g/cm³ (47.3 km/s vesc) |
| Insolation Flux | 20.0716 S⊕ (~27,317 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 221.100 LY (67.786 pc) |