GJ 1002 b
Astrophysical Synthesis & Habitability Characterization
GJ 1002 b is a confirmed terrestrial exoplanet orbiting the star GJ 1002, located approximately 15.8 light-years (4.85 parsecs) from the Solar System. First announced in 2022 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.03 Earth radii and has a measured mass of 1.08 Earth masses. Combining its mass and radius yields a mean bulk density of 5.45 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.02 g⊕ (10 m/s²), and an escape velocity of 11.5 km/s.
In its orbital architecture around GJ 1002, GJ 1002 b completes one full revolution every 10.347 Earth days at a semi-major axis of 0.0457 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 48.1 km/s (compared to Earth's 29.8 km/s).
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 231 K (-42°C / -44°F) and an incident stellar irradiance of 0.67 S⊕ (~912 W/m²), GJ 1002 b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star GJ 1002 is classified as a low-mass red dwarf of spectral type M5.5 V with an effective photospheric temperature of 3,024 K, a radius of 0.137 R☉, a mass of 0.12 M☉, an estimated bolometric luminosity of 0.00141 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.25 dex (metal-poor relative to the Sun). From Earth, GJ 1002 shines at apparent V-band magnitude 13.76 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The GJ 1002 system is a multi-planet architecture hosting 2 confirmed worlds, with GJ 1002 b sharing its stellar neighborhood alongside GJ 1002 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 1002 |
| Spectral Type | M5.5 V |
| Effective Temp (Teff) | 3,024 K |
| Stellar Radius | 0.1370 R☉ |
| Stellar Mass | 0.1200 M☉ |
| Bolometric Luminosity | 0.00141 L☉ |
| Metallicity [Fe/H] | -0.250 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 13.760 · G: 11.780 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.045700 AU |
| Orbital Period | 10.347 days |
| Mean Orbital Velocity | 48.1 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 5.45 g/cm³ (11.5 km/s vesc) |
| Insolation Flux | 0.6700 S⊕ (~912 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 15.800 LY (4.849 pc) |