TOI-5388.01
Astrophysical Synthesis & Habitability Characterization
TOI-5388.01 is a confirmed terrestrial exoplanet orbiting the star TOI-5388, located approximately 60.4 light-years (18.52 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 0.0915% across the stellar disk), this world measures 0.99 Earth radii and has a measured mass of 2.2 Earth masses. Combining its mass and radius yields a mean bulk density of 12.5 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 2.24 g⊕ (21.97 m/s²), and an escape velocity of 16.7 km/s.
In its orbital architecture around TOI-5388, TOI-5388.01 completes one full revolution every 2.595 Earth days at a semi-major axis of 0.024336 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 102 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 488 K (+215°C / +419°F) and receiving 3.30 S⊕ (~4,494 W/m²), TOI-5388.01 orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5388 is classified as a low-mass red dwarf of spectral type M3.0 V with an effective photospheric temperature of 3,440 K, a radius of 0.3 R☉, a mass of 0.292 M☉, an estimated bolometric luminosity of 0.011 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.36 dex (metal-poor relative to the Sun). From Earth, TOI-5388 shines at apparent V-band magnitude 12.728 (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-5388 |
| Spectral Type | M3.0 V |
| Effective Temp (Teff) | 3,440 K |
| Stellar Radius | 0.3000 R☉ |
| Stellar Mass | 0.2920 M☉ |
| Bolometric Luminosity | 0.011 L☉ |
| Metallicity [Fe/H] | -0.360 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.728 · G: 11.728 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.024336 AU |
| Orbital Period | 2.595 days |
| Mean Orbital Velocity | 102 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.8000° |
| Mean Bulk Density | 12.5 g/cm³ (16.7 km/s vesc) |
| Insolation Flux | 3.3023 S⊕ (~4,494 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 60.400 LY (18.523 pc) |