TOI-2202 c
Astrophysical Synthesis & Habitability Characterization
TOI-2202 c is a confirmed gas giant exoplanet orbiting the star TOI-2202, located approximately 769.5 light-years (235.93 parsecs) from the Solar System. First announced in 2021 by Multiple Observatories using the Transit Timing Variations detection technique (producing an estimated primary transit depth of 2.3939% across the stellar disk), this world measures 13.4 Earth radii (1.2 Jupiter radii) and has a measured mass of 117.279 Earth masses (0.37 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.27 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.65 g⊕ (6.37 m/s²), and an escape velocity of 33.1 km/s.
In its orbital architecture around TOI-2202, TOI-2202 c completes one full revolution every 24.674 Earth days at a semi-major axis of 0.15544 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 68.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.0622 carries the world between 0.1458 AU at periapsis and 0.1651 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 561 K (+288°C / +550°F) and receiving 16.43 S⊕ (~22,363 W/m²), TOI-2202 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2202 is classified as an orange K-type star of spectral type K8 V with an effective photospheric temperature of 5,144 K, a radius of 0.794 R☉, a mass of 0.823 M☉, an estimated bolometric luminosity of 0.396 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.48 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, TOI-2202 shines at apparent V-band magnitude 13.004 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The TOI-2202 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-2202 c sharing its stellar neighborhood alongside TOI-2202 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 Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-2202 |
| Spectral Type | K8 V |
| Effective Temp (Teff) | 5,144 K |
| Stellar Radius | 0.7940 R☉ |
| Stellar Mass | 0.8230 M☉ |
| Bolometric Luminosity | 0.396 L☉ |
| Metallicity [Fe/H] | 0.040 dex |
| Stellar Age | 7.480 Gyr |
| Apparent Magnitude | V: 13.004 · G: 12.761 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.155440 AU |
| Orbital Period | 24.674 days |
| Mean Orbital Velocity | 68.5 km/s |
| Orbital Eccentricity (e) | 0.06220 |
| Orbital Inclination (i) | 84.7000° |
| Mean Bulk Density | 0.27 g/cm³ (33.1 km/s vesc) |
| Insolation Flux | 16.4310 S⊕ (~22,363 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 769.500 LY (235.933 pc) |