TOI-1260 d
Astrophysical Synthesis & Habitability Characterization
TOI-1260 d 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 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1812% across the stellar disk), this world measures 3.12 Earth radii (0.28 Jupiter radii) and has a measured mass of 11.84 Earth masses. Combining its mass and radius yields a mean bulk density of 2.15 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 21.8 km/s.
In its orbital architecture around TOI-1260, TOI-1260 d completes one full revolution every 16.608 Earth days at a semi-major axis of 0.1116 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73.1 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 499 K (+226°C / +439°F) and receiving 10.32 S⊕ (~14,046 W/m²), TOI-1260 d 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 d sharing its stellar neighborhood alongside TOI-1260 b, TOI-1260 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-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) | 0.111600 AU |
| Orbital Period | 16.608 days |
| Mean Orbital Velocity | 73.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.1400° |
| Mean Bulk Density | 2.15 g/cm³ (21.8 km/s vesc) |
| Insolation Flux | 10.3200 S⊕ (~14,046 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 240.000 LY (73.598 pc) |