TOI-4342 b
Astrophysical Synthesis & Habitability Characterization
TOI-4342 b is a confirmed sub-neptune exoplanet orbiting the star TOI-4342, located approximately 200.7 light-years (61.52 parsecs) from the Solar System. First announced in 2023 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1275% across the stellar disk), this world measures 2.329 Earth radii and has a measured mass of 7.3 Earth masses. Combining its mass and radius yields a mean bulk density of 3.19 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.35 g⊕ (13.24 m/s²), and an escape velocity of 19.8 km/s.
In its orbital architecture around TOI-4342, TOI-4342 b completes one full revolution every 5.538 Earth days at a semi-major axis of 0.0519 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 101.9 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 639 K (+366°C / +691°F) and receiving 27.80 S⊕ (~37,836 W/m²), TOI-4342 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4342 is classified as a low-mass red dwarf of spectral type M0 V with an effective photospheric temperature of 3,866 K, a radius of 0.598 R☉, a mass of 0.587 M☉, an estimated bolometric luminosity of 0.072 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.26 dex (metal-rich relative to the Sun). From Earth, TOI-4342 shines at apparent V-band magnitude 12.669 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The TOI-4342 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-4342 b sharing its stellar neighborhood alongside TOI-4342 c.
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-4342 |
| Spectral Type | M0 V |
| Effective Temp (Teff) | 3,866 K |
| Stellar Radius | 0.5980 R☉ |
| Stellar Mass | 0.5870 M☉ |
| Bolometric Luminosity | 0.072 L☉ |
| Metallicity [Fe/H] | 0.260 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.669 · G: 11.982 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.051900 AU |
| Orbital Period | 5.538 days |
| Mean Orbital Velocity | 101.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.8300° |
| Mean Bulk Density | 3.19 g/cm³ (19.8 km/s vesc) |
| Insolation Flux | 27.8000 S⊕ (~37,836 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 200.700 LY (61.520 pc) |