TOI-4156 b
Astrophysical Synthesis & Habitability Characterization
TOI-4156 b is a confirmed sub-neptune exoplanet orbiting the star TOI-4156, located approximately 697.1 light-years (213.72 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 0.0501% across the stellar disk), this world measures 2.538 Earth radii and has a measured mass of 6.98 Earth masses. Combining its mass and radius yields a mean bulk density of 2.35 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 18.6 km/s.
In its orbital architecture around TOI-4156, TOI-4156 b completes one full revolution every 4.462 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1289 K (+1016°C / +1861°F) and receiving 459.50 S⊕ (~625,373 W/m²), TOI-4156 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4156 is classified as a stellar host with an effective photospheric temperature of 5,972 K, a radius of 1.0396 R☉, a mass of 1.1 M☉, an estimated bolometric luminosity of 1.233 L☉. From Earth, TOI-4156 shines at apparent V-band magnitude 11.504 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-4156 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-4156 b sharing its stellar neighborhood alongside TOI-4156 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-4156 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,972 K |
| Stellar Radius | 1.0396 R☉ |
| Stellar Mass | 1.1000 M☉ |
| Bolometric Luminosity | 1.233 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 11.504 · G: 11.126 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 4.462 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 87.0930° |
| Mean Bulk Density | 2.35 g/cm³ (18.6 km/s vesc) |
| Insolation Flux | 459.4950 S⊕ (~625,373 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 697.100 LY (213.719 pc) |