TOI-1260 c
Astrophysical Synthesis & Habitability Characterization
TOI-1260 c is a confirmed sub-neptune exoplanet orbiting the star TOI-1260, located approximately 240 light-years (73.6 parsecs) from the Solar System. First announced in 2021 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1418% across the stellar disk), this world measures 2.76 Earth radii and has a measured mass of 13.2 Earth masses. Combining its mass and radius yields a mean bulk density of 3.46 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.73 g⊕ (16.97 m/s²), and an escape velocity of 24.5 km/s.
In its orbital architecture around TOI-1260, TOI-1260 c completes one full revolution every 7.493 Earth days at a semi-major axis of 0.0657 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 95.4 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 651 K (+378°C / +712°F) and receiving 29.81 S⊕ (~40,571 W/m²), TOI-1260 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1260 is classified as an orange K-type star of spectral type K6 V with an effective photospheric temperature of 4,227 K, a radius of 0.672 R☉, a mass of 0.679 M☉, an estimated bolometric luminosity of 0.129 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.7 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, TOI-1260 shines at apparent V-band magnitude 11.922 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1260 system is a multi-planet architecture hosting 3 confirmed worlds, with TOI-1260 c sharing its stellar neighborhood alongside TOI-1260 b, TOI-1260 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-1260 |
| Spectral Type | K6 V |
| Effective Temp (Teff) | 4,227 K |
| Stellar Radius | 0.6720 R☉ |
| Stellar Mass | 0.6790 M☉ |
| Bolometric Luminosity | 0.129 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 6.700 Gyr |
| Apparent Magnitude | V: 11.922 · G: 11.574 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.065700 AU |
| Orbital Period | 7.493 days |
| Mean Orbital Velocity | 95.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.9700° |
| Mean Bulk Density | 3.46 g/cm³ (24.5 km/s vesc) |
| Insolation Flux | 29.8100 S⊕ (~40,571 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 240.000 LY (73.598 pc) |