TOI-5720 b
Astrophysical Synthesis & Habitability Characterization
TOI-5720 b is a confirmed terrestrial exoplanet orbiting the star TOI-5720, located approximately 116.8 light-years (35.83 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0681% across the stellar disk), this world measures 1.09 Earth radii and has a measured mass of 4.3 Earth masses. Combining its mass and radius yields a mean bulk density of 18.31 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 3.62 g⊕ (35.5 m/s²), and an escape velocity of 22.2 km/s.
In its orbital architecture around TOI-5720, TOI-5720 b completes one full revolution every 1.434 Earth days at a semi-major axis of 0.018288 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 138.7 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 708 K (+435°C / +815°F) and receiving 41.70 S⊕ (~56,754 W/m²), TOI-5720 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5720 is classified as a low-mass red dwarf of spectral type M3.5 +/- 1.0 with an effective photospheric temperature of 3,325 K, a radius of 0.383 R☉, a mass of 0.383 M☉, an estimated bolometric luminosity of 0.016 L☉. Stellar evolution modeling indicates an estimated stellar age of 5 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, TOI-5720 shines at apparent V-band magnitude 13.847 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-5720 |
| Spectral Type | M3.5 +/- 1.0 |
| Effective Temp (Teff) | 3,325 K |
| Stellar Radius | 0.3830 R☉ |
| Stellar Mass | 0.3830 M☉ |
| Bolometric Luminosity | 0.016 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 5.000 Gyr |
| Apparent Magnitude | V: 13.847 · G: 12.822 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.018288 AU |
| Orbital Period | 1.434 days |
| Mean Orbital Velocity | 138.7 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.3000° |
| Mean Bulk Density | 18.31 g/cm³ (22.2 km/s vesc) |
| Insolation Flux | 41.7000 S⊕ (~56,754 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 116.800 LY (35.826 pc) |