HD 220074 b
Astrophysical Synthesis & Habitability Characterization
HD 220074 b is a confirmed gas giant exoplanet orbiting the star HD 220074, located approximately 1058.5 light-years (324.54 parsecs) from the Solar System. First announced in 2012 by Bohyunsan Optical Astronomical Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.2 Earth radii (1.09 Jupiter radii) and has a measured mass of 5288.691 Earth masses (16.64 Jupiter masses). Combining its mass and radius yields a mean bulk density of 16.06 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 35.53 g⊕ (348.43 m/s²), and an escape velocity of 232.9 km/s.
In its orbital architecture around HD 220074, HD 220074 b completes one full revolution every 672.1 Earth days (1.84Julian years) at a semi-major axis of 1.6 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 25.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.14 carries the world between 1.376 AU at periapsis and 1.824 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1070 K (+797°C / +1467°F) and receiving 305.70 S⊕ (~416,064 W/m²), HD 220074 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 220074 is classified as a low-mass red dwarf of spectral type M2 III with an effective photospheric temperature of 3,787 K, a radius of 54.92 R☉, a mass of 2.2 M☉, an estimated bolometric luminosity of 556.586 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.5 Gyr and a metallicity of [Fe/H] = -0.25 dex (metal-poor relative to the Sun). From Earth, HD 220074 shines at apparent V-band magnitude 6.406 (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: Bohyunsan Optical Astronomical Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 220074 |
| Spectral Type | M2 III |
| Effective Temp (Teff) | 3,787 K |
| Stellar Radius | 54.9200 R☉ |
| Stellar Mass | 2.2000 M☉ |
| Bolometric Luminosity | 556.586 L☉ |
| Metallicity [Fe/H] | -0.250 dex |
| Stellar Age | 4.500 Gyr |
| Apparent Magnitude | V: 6.406 · G: 5.627 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.600000 AU |
| Orbital Period | 672.1 days |
| Mean Orbital Velocity | 25.9 km/s |
| Orbital Eccentricity (e) | 0.14000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 16.06 g/cm³ (232.9 km/s vesc) |
| Insolation Flux | 305.7049 S⊕ (~416,064 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1058.500 LY (324.540 pc) |