TOI-1670 c
Astrophysical Synthesis & Habitability Characterization
TOI-1670 c is a confirmed gas giant exoplanet orbiting the star TOI-1670, located approximately 548.2 light-years (168.07 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 0.594% across the stellar disk), this world measures 11.063 Earth radii (0.99 Jupiter radii) and has a measured mass of 200.232 Earth masses (0.63 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.82 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.64 g⊕ (16.08 m/s²), and an escape velocity of 47.6 km/s.
In its orbital architecture around TOI-1670, TOI-1670 c completes one full revolution every 40.75 Earth days at a semi-major axis of 0.249 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 66.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.09 carries the world between 0.2266 AU at periapsis and 0.2714 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 684 K (+411°C / +772°F) and receiving 14.55 S⊕ (~19,804 W/m²), TOI-1670 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1670 is classified as a warm F-type star of spectral type F7 V with an effective photospheric temperature of 6,170 K, a radius of 1.316 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 2.252 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.53 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, TOI-1670 shines at apparent V-band magnitude 9.889 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The TOI-1670 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-1670 c sharing its stellar neighborhood alongside TOI-1670 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-1670 |
| Spectral Type | F7 V |
| Effective Temp (Teff) | 6,170 K |
| Stellar Radius | 1.3160 R☉ |
| Stellar Mass | 1.2100 M☉ |
| Bolometric Luminosity | 2.252 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 2.530 Gyr |
| Apparent Magnitude | V: 9.889 · G: 9.819 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.249000 AU |
| Orbital Period | 40.75 days |
| Mean Orbital Velocity | 66.5 km/s |
| Orbital Eccentricity (e) | 0.09000 |
| Orbital Inclination (i) | 88.8400° |
| Mean Bulk Density | 0.82 g/cm³ (47.6 km/s vesc) |
| Insolation Flux | 14.5514 S⊕ (~19,804 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 548.200 LY (168.067 pc) |