TOI-201 c
Astrophysical Synthesis & Habitability Characterization
TOI-201 c is a confirmed gas giant exoplanet orbiting the star TOI-201, located approximately 371.2 light-years (113.83 parsecs) from the Solar System. First announced in 2025 by Transiting Exoplanet Survey Satellite (TESS) using the Transit Timing Variations detection technique (producing an estimated primary transit depth of 0.5297% across the stellar disk), this world measures 10.4 Earth radii (0.93 Jupiter radii) and has a measured mass of 4990 Earth masses (15.7 Jupiter masses). Combining its mass and radius yields a mean bulk density of 24.46 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 46.14 g⊕ (452.48 m/s²), and an escape velocity of 245 km/s.
In its orbital architecture around TOI-201, TOI-201 c completes one full revolution every 2890 Earth days (7.91Julian years) at a semi-major axis of 4.37 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 16.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.651, swinging from 1.5251 AU at periapsis out to 7.2149 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 170 K (-103°C / -153°F) and an incident flux of 0.14 S⊕ (~186 W/m²), surface water and volatile species on TOI-201 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star TOI-201 is classified as a warm F-type star of spectral type F with an effective photospheric temperature of 6,423 K, a radius of 1.31 R☉, a mass of 1.32 M☉, an estimated bolometric luminosity of 2.62 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.666 Gyr and a metallicity of [Fe/H] = 0.24 dex (metal-rich relative to the Sun). From Earth, TOI-201 shines at apparent V-band magnitude 9.07 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The TOI-201 system is a multi-planet architecture hosting 3 confirmed worlds, with TOI-201 c sharing its stellar neighborhood alongside TOI-201 d, TOI-201 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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-201 |
| Spectral Type | F |
| Effective Temp (Teff) | 6,423 K |
| Stellar Radius | 1.3100 R☉ |
| Stellar Mass | 1.3200 M☉ |
| Bolometric Luminosity | 2.62 L☉ |
| Metallicity [Fe/H] | 0.240 dex |
| Stellar Age | 0.666 Gyr |
| Apparent Magnitude | V: 9.070 · G: 8.940 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 4.370000 AU |
| Orbital Period | 2890 days |
| Mean Orbital Velocity | 16.5 km/s |
| Orbital Eccentricity (e) | 0.65100 |
| Orbital Inclination (i) | 89.9200° |
| Mean Bulk Density | 24.46 g/cm³ (245 km/s vesc) |
| Insolation Flux | 0.1367 S⊕ (~186 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 371.200 LY (113.825 pc) |