TOI-2345 c
Astrophysical Synthesis & Habitability Characterization
TOI-2345 c is a confirmed sub-neptune exoplanet orbiting the star TOI-2345, located approximately 266.3 light-years (81.65 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 0.095% across the stellar disk), this world measures 2.451 Earth radii and has a measured mass of 7.27 Earth masses. Combining its mass and radius yields a mean bulk density of 2.72 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 19.3 km/s.
In its orbital architecture around TOI-2345, TOI-2345 c completes one full revolution every 21.064 Earth days at a semi-major axis of 0.1257 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 64.9 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 544 K (+271°C / +520°F) and receiving 14.57 S⊕ (~19,830 W/m²), TOI-2345 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2345 is classified as an orange K-type star of spectral type K with an effective photospheric temperature of 4,687 K, a radius of 0.729 R☉, a mass of 0.727 M☉, an estimated bolometric luminosity of 0.23 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.3 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, TOI-2345 shines at apparent V-band magnitude 11.483 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The TOI-2345 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-2345 c sharing its stellar neighborhood alongside TOI-2345 b.
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-2345 |
| Spectral Type | K |
| Effective Temp (Teff) | 4,687 K |
| Stellar Radius | 0.7290 R☉ |
| Stellar Mass | 0.7270 M☉ |
| Bolometric Luminosity | 0.23 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 6.300 Gyr |
| Apparent Magnitude | V: 11.483 · G: 11.028 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.125700 AU |
| Orbital Period | 21.064 days |
| Mean Orbital Velocity | 64.9 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.9140° |
| Mean Bulk Density | 2.72 g/cm³ (19.3 km/s vesc) |
| Insolation Flux | 14.5700 S⊕ (~19,830 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 266.300 LY (81.654 pc) |