TOI-969 b
Astrophysical Synthesis & Habitability Characterization
TOI-969 b is a confirmed sub-neptune exoplanet orbiting the star TOI-969, located approximately 252 light-years (77.26 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 0.1427% across the stellar disk), this world measures 2.765 Earth radii and has a measured mass of 9.1 Earth masses. Combining its mass and radius yields a mean bulk density of 2.37 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 20.3 km/s.
In its orbital architecture around TOI-969, TOI-969 b completes one full revolution every 1.824 Earth days at a semi-major axis of 0.02636 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 157.2 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 941 K (+668°C / +1234°F) and receiving 188.00 S⊕ (~255,868 W/m²), TOI-969 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-969 is classified as an orange K-type star of spectral type K V with an effective photospheric temperature of 4,435 K, a radius of 0.671 R☉, a mass of 0.734 M☉, an estimated bolometric luminosity of 0.156 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.03 Gyr and a metallicity of [Fe/H] = 0.175 dex (metal-rich relative to the Sun). From Earth, TOI-969 shines at apparent V-band magnitude 11.646 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-969 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-969 b sharing its stellar neighborhood alongside TOI-969 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-969 |
| Spectral Type | K V |
| Effective Temp (Teff) | 4,435 K |
| Stellar Radius | 0.6710 R☉ |
| Stellar Mass | 0.7340 M☉ |
| Bolometric Luminosity | 0.156 L☉ |
| Metallicity [Fe/H] | 0.175 dex |
| Stellar Age | 2.030 Gyr |
| Apparent Magnitude | V: 11.646 · G: 11.267 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.026360 AU |
| Orbital Period | 1.824 days |
| Mean Orbital Velocity | 157.2 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 86.7500° |
| Mean Bulk Density | 2.37 g/cm³ (20.3 km/s vesc) |
| Insolation Flux | 188.0000 S⊕ (~255,868 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 252.000 LY (77.255 pc) |