TOI-2180 b
Astrophysical Synthesis & Habitability Characterization
TOI-2180 b is a confirmed gas giant exoplanet orbiting the star TOI-2180, located approximately 380.6 light-years (116.69 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 0.4025% across the stellar disk), this world measures 11.321 Earth radii (1.01 Jupiter radii) and has a measured mass of 875.617 Earth masses (2.75 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.33 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 6.83 g⊕ (66.98 m/s²), and an escape velocity of 98.4 km/s.
In its orbital architecture around TOI-2180, TOI-2180 b completes one full revolution every 260.79 Earth days at a semi-major axis of 0.828 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 34.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.3683, swinging from 0.523 AU at periapsis out to 1.133 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 11.321 R⊕, TOI-2180 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star TOI-2180 is classified as a solar-type yellow star of spectral type G5 with an effective photospheric temperature of 5,695 K, a radius of 1.636 R☉, a mass of 1.111 M☉, an estimated bolometric luminosity of 2.526 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.1 Gyr and a metallicity of [Fe/H] = 0.253 dex (metal-rich relative to the Sun). From Earth, TOI-2180 shines at apparent V-band magnitude 9.162 (accessible to binoculars and small amateur telescopes) 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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-2180 |
| Spectral Type | G5 |
| Effective Temp (Teff) | 5,695 K |
| Stellar Radius | 1.6360 R☉ |
| Stellar Mass | 1.1110 M☉ |
| Bolometric Luminosity | 2.526 L☉ |
| Metallicity [Fe/H] | 0.253 dex |
| Stellar Age | 8.100 Gyr |
| Apparent Magnitude | V: 9.162 · G: 9.011 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.828000 AU |
| Orbital Period | 260.79 days |
| Mean Orbital Velocity | 34.5 km/s |
| Orbital Eccentricity (e) | 0.36830 |
| Orbital Inclination (i) | 89.9550° |
| Mean Bulk Density | 3.33 g/cm³ (98.4 km/s vesc) |
| Insolation Flux | 2.7100 S⊕ (~3,688 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 380.600 LY (116.685 pc) |