GJ 3090 c
Astrophysical Synthesis & Habitability Characterization
GJ 3090 c is a confirmed sub-neptune exoplanet orbiting the star GJ 3090, located approximately 73.3 light-years (22.48 parsecs) from the Solar System. First announced in 2026 by Multiple Facilities using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 3.14 Earth radii (0.28 Jupiter radii) and has a measured mass of 10 Earth masses. Combining its mass and radius yields a mean bulk density of 1.78 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.01 g⊕ (9.9 m/s²), and an escape velocity of 20 km/s.
In its orbital architecture around GJ 3090, GJ 3090 c completes one full revolution every 15.941 Earth days at a semi-major axis of 0.0997 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 68 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 407 K (+134°C / +273°F) and receiving 4.58 S⊕ (~6,233 W/m²), GJ 3090 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star GJ 3090 is classified as a low-mass red dwarf of spectral type M2 V with an effective photospheric temperature of 3,707 K, a radius of 0.516 R☉, a mass of 0.519 M☉, an estimated bolometric luminosity of 0.045 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.12 dex (metal-rich relative to the Sun). From Earth, GJ 3090 shines at apparent V-band magnitude 11.403 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The GJ 3090 system is a multi-planet architecture hosting 2 confirmed worlds, with GJ 3090 c sharing its stellar neighborhood alongside GJ 3090 b.
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 Facilities · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 3090 |
| Spectral Type | M2 V |
| Effective Temp (Teff) | 3,707 K |
| Stellar Radius | 0.5160 R☉ |
| Stellar Mass | 0.5190 M☉ |
| Bolometric Luminosity | 0.045 L☉ |
| Metallicity [Fe/H] | 0.120 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 11.403 · G: 10.552 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.099700 AU |
| Orbital Period | 15.941 days |
| Mean Orbital Velocity | 68 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.78 g/cm³ (20 km/s vesc) |
| Insolation Flux | 4.5800 S⊕ (~6,233 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 73.300 LY (22.475 pc) |