TOI-1806.01
Astrophysical Synthesis & Habitability Characterization
TOI-1806.01 is a confirmed sub-neptune exoplanet orbiting the star TOI-1806, located approximately 181.1 light-years (55.52 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 0.606% across the stellar disk), this world measures 3.41 Earth radii (0.3 Jupiter radii) and has a measured mass of 11.5 Earth masses. Combining its mass and radius yields a mean bulk density of 1.6 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.99 g⊕ (9.71 m/s²), and an escape velocity of 20.5 km/s.
In its orbital architecture around TOI-1806, TOI-1806.01 completes one full revolution every 15.145 Earth days at a semi-major axis of 0.087735 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 63 km/s (compared to Earth's 29.8 km/s).
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 3.410 R⊕, TOI-1806.01 exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star TOI-1806 is classified as a stellar host with an effective photospheric temperature of 3,272 K, a radius of 0.4016 R☉, a mass of 0.3929 M☉, an estimated bolometric luminosity of 0.017 L☉. From Earth, TOI-1806 shines at apparent V-band magnitude 15.193 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1806 system is a multi-planet architecture hosting 3 confirmed worlds, with TOI-1806.01 sharing its stellar neighborhood alongside TOI-1806 c, TOI-1806 d.
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-1806 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,272 K |
| Stellar Radius | 0.4016 R☉ |
| Stellar Mass | 0.3929 M☉ |
| Bolometric Luminosity | 0.017 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 15.193 · G: 13.927 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.087735 AU |
| Orbital Period | 15.145 days |
| Mean Orbital Velocity | 63 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.6 g/cm³ (20.5 km/s vesc) |
| Insolation Flux | 2.1473 S⊕ (~2,922 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 181.100 LY (55.521 pc) |