HD 63454 b
Astrophysical Synthesis & Habitability Characterization
HD 63454 b is a confirmed gas giant exoplanet orbiting the star HD 63454, located approximately 122.9 light-years (37.69 parsecs) from the Solar System. First announced in 2005 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.31 Earth radii (1.1 Jupiter radii) and has a measured mass of 79.458 Earth masses (0.25 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.23 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.52 g⊕ (5.1 m/s²), and an escape velocity of 28.4 km/s.
In its orbital architecture around HD 63454, HD 63454 b completes one full revolution every 2.818 Earth days at a semi-major axis of 0.04 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 154.4 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1018 K (+745°C / +1373°F) and receiving 159.91 S⊕ (~217,640 W/m²), HD 63454 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 63454 is classified as an orange K-type star of spectral type K4 V with an effective photospheric temperature of 4,812 K, a radius of 0.77 R☉, a mass of 0.42 M☉, an estimated bolometric luminosity of 0.285 L☉. Stellar evolution modeling indicates an estimated stellar age of 1 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, HD 63454 shines at apparent V-band magnitude 9.37 (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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 63454 |
| Spectral Type | K4 V |
| Effective Temp (Teff) | 4,812 K |
| Stellar Radius | 0.7700 R☉ |
| Stellar Mass | 0.4200 M☉ |
| Bolometric Luminosity | 0.285 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 1.000 Gyr |
| Apparent Magnitude | V: 9.370 · G: 9.054 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.040000 AU |
| Orbital Period | 2.818 days |
| Mean Orbital Velocity | 154.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.23 g/cm³ (28.4 km/s vesc) |
| Insolation Flux | 159.9116 S⊕ (~217,640 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 122.900 LY (37.689 pc) |