TOI-5542 b
Astrophysical Synthesis & Habitability Characterization
TOI-5542 b is a confirmed gas giant exoplanet orbiting the star TOI-5542, located approximately 1137.8 light-years (348.85 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 0.9605% across the stellar disk), this world measures 11.31 Earth radii (1.01 Jupiter radii) and has a measured mass of 419.533 Earth masses (1.32 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.6 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.28 g⊕ (32.17 m/s²), and an escape velocity of 68.1 km/s.
In its orbital architecture around TOI-5542, TOI-5542 b completes one full revolution every 75.124 Earth days at a semi-major axis of 0.332 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 48.1 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.018 (ranging from 0.326 AU at periapsis to 0.338 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 441 K (+168°C / +334°F) and receiving 9.60 S⊕ (~13,066 W/m²), TOI-5542 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5542 is classified as a solar-type yellow star of spectral type G3 V with an effective photospheric temperature of 5,700 K, a radius of 1.058 R☉, a mass of 0.89 M☉, an estimated bolometric luminosity of 1.06 L☉. Stellar evolution modeling indicates an estimated stellar age of 10.8 Gyr and a metallicity of [Fe/H] = -0.21 dex (metal-poor relative to the Sun). From Earth, TOI-5542 shines at apparent V-band magnitude 12.42 (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-5542 |
| Spectral Type | G3 V |
| Effective Temp (Teff) | 5,700 K |
| Stellar Radius | 1.0580 R☉ |
| Stellar Mass | 0.8900 M☉ |
| Bolometric Luminosity | 1.06 L☉ |
| Metallicity [Fe/H] | -0.210 dex |
| Stellar Age | 10.800 Gyr |
| Apparent Magnitude | V: 12.420 · G: 12.282 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.332000 AU |
| Orbital Period | 75.124 days |
| Mean Orbital Velocity | 48.1 km/s |
| Orbital Eccentricity (e) | 0.01800 |
| Orbital Inclination (i) | 89.6430° |
| Mean Bulk Density | 1.6 g/cm³ (68.1 km/s vesc) |
| Insolation Flux | 9.6000 S⊕ (~13,066 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1137.800 LY (348.849 pc) |