TOI-283 b
Astrophysical Synthesis & Habitability Characterization
TOI-283 b is a confirmed sub-neptune exoplanet orbiting the star TOI-283, located approximately 269.7 light-years (82.7 parsecs) from the Solar System. First announced in 2025 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0637% across the stellar disk), this world measures 2.34 Earth radii and has a measured mass of 6.54 Earth masses. Combining its mass and radius yields a mean bulk density of 2.81 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 18.7 km/s.
In its orbital architecture around TOI-283, TOI-283 b completes one full revolution every 17.617 Earth days at a semi-major axis of 0.123 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 76 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.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 661 K (+388°C / +730°F) and receiving 30.40 S⊕ (~41,374 W/m²), TOI-283 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-283 is classified as an orange K-type star of spectral type K with an effective photospheric temperature of 5,213 K, a radius of 0.85 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.479 L☉. Stellar evolution modeling indicates an estimated stellar age of 10.4 Gyr and a metallicity of [Fe/H] = -0.09 dex (near-solar heavy-element abundance). From Earth, TOI-283 shines at apparent V-band magnitude 10.41 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-283 |
| Spectral Type | K |
| Effective Temp (Teff) | 5,213 K |
| Stellar Radius | 0.8500 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.479 L☉ |
| Metallicity [Fe/H] | -0.090 dex |
| Stellar Age | 10.400 Gyr |
| Apparent Magnitude | V: 10.410 · G: 10.197 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.123000 AU |
| Orbital Period | 17.617 days |
| Mean Orbital Velocity | 76 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.1200° |
| Mean Bulk Density | 2.81 g/cm³ (18.7 km/s vesc) |
| Insolation Flux | 30.4000 S⊕ (~41,374 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 269.700 LY (82.701 pc) |