TOI-4336 A b
Astrophysical Synthesis & Habitability Characterization
TOI-4336 A b is a confirmed sub-neptune exoplanet orbiting the star TOI-4336 A, located approximately 73.5 light-years (22.55 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.3612% across the stellar disk), this world measures 2.137 Earth radii and has a measured mass of 3.33 Earth masses. Combining its mass and radius yields a mean bulk density of 1.88 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.73 g⊕ (7.16 m/s²), and an escape velocity of 14 km/s.
In its orbital architecture around TOI-4336 A, TOI-4336 A b completes one full revolution every 16.336 Earth days at a semi-major axis of 0.0849 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 56.5 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 309 K (+36°C / +97°F) and an incident stellar irradiance of 1.53 S⊕ (~2,082 W/m²), TOI-4336 A b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star TOI-4336 A is classified as a low-mass red dwarf of spectral type M3.5 V with an effective photospheric temperature of 3,307 K, a radius of 0.326 R☉, a mass of 0.306 M☉, an estimated bolometric luminosity of 0.011 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.7 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, TOI-4336 A shines at apparent V-band magnitude 13.6 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The TOI-4336 A system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-4336 A b sharing its stellar neighborhood alongside TOI-4336 A c.
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-4336 A |
| Spectral Type | M3.5 V |
| Effective Temp (Teff) | 3,307 K |
| Stellar Radius | 0.3260 R☉ |
| Stellar Mass | 0.3060 M☉ |
| Bolometric Luminosity | 0.011 L☉ |
| Metallicity [Fe/H] | 0.140 dex |
| Stellar Age | 6.700 Gyr |
| Apparent Magnitude | V: 13.600 · G: 12.257 |
| System Architecture | 3 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.084900 AU |
| Orbital Period | 16.336 days |
| Mean Orbital Velocity | 56.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4920° |
| Mean Bulk Density | 1.88 g/cm³ (14 km/s vesc) |
| Insolation Flux | 1.5300 S⊕ (~2,082 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 73.500 LY (22.546 pc) |