TOI-3629 b
Astrophysical Synthesis & Habitability Characterization
TOI-3629 b is a confirmed gas giant exoplanet orbiting the star TOI-3629, located approximately 424.3 light-years (130.09 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 1.6065% across the stellar disk), this world measures 8.295 Earth radii (0.74 Jupiter radii) and has a measured mass of 82.635 Earth masses (0.26 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.8 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.2 g⊕ (11.77 m/s²), and an escape velocity of 35.3 km/s.
In its orbital architecture around TOI-3629, TOI-3629 b completes one full revolution every 3.937 Earth days at a semi-major axis of 0.043 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 118.8 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.05 carries the world between 0.0409 AU at periapsis and 0.0451 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 690 K (+417°C / +783°F) and receiving 39.00 S⊕ (~53,079 W/m²), TOI-3629 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3629 is classified as a low-mass red dwarf of spectral type M1 with an effective photospheric temperature of 3,870 K, a radius of 0.6 R☉, a mass of 0.63 M☉, an estimated bolometric luminosity of 0.072 L☉. Stellar evolution modeling indicates an estimated stellar age of 7 Gyr and a metallicity of [Fe/H] = 0.4 dex (metal-rich relative to the Sun). From Earth, TOI-3629 shines at apparent V-band magnitude 14.639 (faint and requiring research-grade or CCD telescopic photometry) 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-3629 |
| Spectral Type | M1 |
| Effective Temp (Teff) | 3,870 K |
| Stellar Radius | 0.6000 R☉ |
| Stellar Mass | 0.6300 M☉ |
| Bolometric Luminosity | 0.072 L☉ |
| Metallicity [Fe/H] | 0.400 dex |
| Stellar Age | 7.000 Gyr |
| Apparent Magnitude | V: 14.639 · G: 13.838 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.043000 AU |
| Orbital Period | 3.937 days |
| Mean Orbital Velocity | 118.8 km/s |
| Orbital Eccentricity (e) | 0.05000 |
| Orbital Inclination (i) | 89.1000° |
| Mean Bulk Density | 0.8 g/cm³ (35.3 km/s vesc) |
| Insolation Flux | 39.0000 S⊕ (~53,079 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 424.300 LY (130.091 pc) |