TOI-5531 b
Astrophysical Synthesis & Habitability Characterization
TOI-5531 b is a confirmed super-earth exoplanet orbiting the star TOI-5531, located approximately 263 light-years (80.64 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 0.0147% across the stellar disk), this world measures 1.46 Earth radii and has a measured mass of 2.73 Earth masses. Combining its mass and radius yields a mean bulk density of 4.84 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.28 g⊕ (12.55 m/s²), and an escape velocity of 15.3 km/s.
In its orbital architecture around TOI-5531, TOI-5531 b completes one full revolution every 4.535 Earth days. 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 1150 K (+877°C / +1611°F) and receiving 413.86 S⊕ (~563,258 W/m²), TOI-5531 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5531 is classified as a stellar host with an effective photospheric temperature of 5,788 K, a radius of 1.1026 R☉, a mass of 1.04 M☉, an estimated bolometric luminosity of 1.224 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.336 dex (metal-poor relative to the Sun). From Earth, TOI-5531 shines at apparent V-band magnitude 9.12 (accessible to binoculars and small amateur telescopes) 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-5531 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,788 K |
| Stellar Radius | 1.1026 R☉ |
| Stellar Mass | 1.0400 M☉ |
| Bolometric Luminosity | 1.224 L☉ |
| Metallicity [Fe/H] | -0.336 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 9.120 · G: 8.987 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 4.535 days |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.84 g/cm³ (15.3 km/s vesc) |
| Insolation Flux | 413.8560 S⊕ (~563,258 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 263.000 LY (80.640 pc) |