GPX-1 b
Astrophysical Synthesis & Habitability Characterization
GPX-1 b is a confirmed gas giant exoplanet orbiting the star GPX-1, located approximately 2136.4 light-years (655.01 parsecs) from the Solar System. First announced in 2021 by Acton Sky Portal Observatory using the Transit detection technique (producing an estimated primary transit depth of 0.9377% across the stellar disk), this world measures 16.477 Earth radii (1.47 Jupiter radii) and has a measured mass of 6261.22 Earth masses (19.7 Jupiter masses). Combining its mass and radius yields a mean bulk density of 7.72 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 23.06 g⊕ (226.14 m/s²), and an escape velocity of 218.1 km/s.
In its orbital architecture around GPX-1, GPX-1 b completes one full revolution every 1.745 Earth days at a semi-major axis of 0.0338 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 210.8 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 2300 K (+2027°C / +3681°F) and receiving 4,650.00 S⊕ (~6,328,650 W/m²), GPX-1 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star GPX-1 is classified as a warm F-type star of spectral type F2 with an effective photospheric temperature of 7,000 K, a radius of 1.56 R☉, a mass of 1.68 M☉, an estimated bolometric luminosity of 5.242 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.27 Gyr and a metallicity of [Fe/H] = 0.35 dex (metal-rich relative to the Sun). From Earth, GPX-1 shines at apparent V-band magnitude 12.316 (faint and requiring research-grade or CCD telescopic photometry) 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: Acton Sky Portal Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GPX-1 |
| Spectral Type | F2 |
| Effective Temp (Teff) | 7,000 K |
| Stellar Radius | 1.5600 R☉ |
| Stellar Mass | 1.6800 M☉ |
| Bolometric Luminosity | 5.242 L☉ |
| Metallicity [Fe/H] | 0.350 dex |
| Stellar Age | 0.270 Gyr |
| Apparent Magnitude | V: 12.316 · G: 12.223 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.033800 AU |
| Orbital Period | 1.745 days |
| Mean Orbital Velocity | 210.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 79.9000° |
| Mean Bulk Density | 7.72 g/cm³ (218.1 km/s vesc) |
| Insolation Flux | 4650.0000 S⊕ (~6,328,650 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2136.400 LY (655.013 pc) |