TOI-4552 b
Astrophysical Synthesis & Habitability Characterization
TOI-4552 b is a confirmed terrestrial exoplanet orbiting the star TOI-4552, located approximately 88.9 light-years (27.27 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1258% across the stellar disk), this world measures 1.11 Earth radii and has a measured mass of 1.83 Earth masses. Combining its mass and radius yields a mean bulk density of 7.38 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 1.49 g⊕ (14.61 m/s²), and an escape velocity of 14.4 km/s.
In its orbital architecture around TOI-4552, TOI-4552 b completes one full revolution every 0.301 Earth days at a semi-major axis of 0.005626 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 203.3 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 1122 K (+849°C / +1560°F) and receiving 263.00 S⊕ (~357,943 W/m²), TOI-4552 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4552 is classified as a low-mass red dwarf of spectral type M4.5 V with an effective photospheric temperature of 3,258 K, a radius of 0.2869 R☉, a mass of 0.2619 M☉, an estimated bolometric luminosity of 0.00832 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.07 dex (near-solar heavy-element abundance). From Earth, TOI-4552 shines at apparent V-band magnitude 14.44 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-4552 |
| Spectral Type | M4.5 V |
| Effective Temp (Teff) | 3,258 K |
| Stellar Radius | 0.2869 R☉ |
| Stellar Mass | 0.2619 M☉ |
| Bolometric Luminosity | 0.00832 L☉ |
| Metallicity [Fe/H] | -0.070 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 14.440 · G: 13.239 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.005626 AU |
| Orbital Period | 0.301 days |
| Mean Orbital Velocity | 203.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.7700° |
| Mean Bulk Density | 7.38 g/cm³ (14.4 km/s vesc) |
| Insolation Flux | 263.0000 S⊕ (~357,943 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 88.900 LY (27.268 pc) |