TOI-2427 c
Astrophysical Synthesis & Habitability Characterization
TOI-2427 c is a confirmed sub-neptune exoplanet orbiting the star TOI-2427, located approximately 93 light-years (28.52 parsecs) from the Solar System. First announced in 2025 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 2.43 Earth radii and has a measured mass of 6.46 Earth masses. Combining its mass and radius yields a mean bulk density of 2.48 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.09 g⊕ (10.69 m/s²), and an escape velocity of 18.2 km/s.
In its orbital architecture around TOI-2427, TOI-2427 c completes one full revolution every 5.15 Earth days at a semi-major axis of 0.05 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 105.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.089 carries the world between 0.0456 AU at periapsis and 0.0545 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 730 K (+457°C / +855°F) and receiving 44.00 S⊕ (~59,884 W/m²), TOI-2427 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2427 is classified as an orange K-type star of spectral type K7 V with an effective photospheric temperature of 4,203 K, a radius of 0.648 R☉, a mass of 0.639 M☉, an estimated bolometric luminosity of 0.118 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.58 Gyr and a metallicity of [Fe/H] = -0.21 dex (metal-poor relative to the Sun). From Earth, TOI-2427 shines at apparent V-band magnitude 10.295 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The TOI-2427 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-2427 c sharing its stellar neighborhood alongside TOI-2427 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-2427 |
| Spectral Type | K7 V |
| Effective Temp (Teff) | 4,203 K |
| Stellar Radius | 0.6480 R☉ |
| Stellar Mass | 0.6390 M☉ |
| Bolometric Luminosity | 0.118 L☉ |
| Metallicity [Fe/H] | -0.210 dex |
| Stellar Age | 1.580 Gyr |
| Apparent Magnitude | V: 10.295 · G: 9.818 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050000 AU |
| Orbital Period | 5.15 days |
| Mean Orbital Velocity | 105.6 km/s |
| Orbital Eccentricity (e) | 0.08900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.48 g/cm³ (18.2 km/s vesc) |
| Insolation Flux | 44.0000 S⊕ (~59,884 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 93.000 LY (28.515 pc) |