GJ 3090 b
Astrophysical Synthesis & Habitability Characterization
GJ 3090 b 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 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.15% across the stellar disk), this world measures 2.18 Earth radii and has a measured mass of 4.52 Earth masses. Combining its mass and radius yields a mean bulk density of 2.41 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 0.95 g⊕ (9.32 m/s²), and an escape velocity of 16.1 km/s.
In its orbital architecture around GJ 3090, GJ 3090 b completes one full revolution every 2.853 Earth days at a semi-major axis of 0.0316 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 120.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.25, swinging from 0.0237 AU at periapsis out to 0.0395 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 723 K (+450°C / +842°F) and receiving 45.40 S⊕ (~61,789 W/m²), GJ 3090 b 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 b sharing its stellar neighborhood alongside GJ 3090 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: Transiting Exoplanet Survey Satellite (TESS) · 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) | 0.031600 AU |
| Orbital Period | 2.853 days |
| Mean Orbital Velocity | 120.5 km/s |
| Orbital Eccentricity (e) | 0.25000 |
| Orbital Inclination (i) | 86.9000° |
| Mean Bulk Density | 2.41 g/cm³ (16.1 km/s vesc) |
| Insolation Flux | 45.4000 S⊕ (~61,789 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 73.300 LY (22.475 pc) |