TOI-2876 b
Astrophysical Synthesis & Habitability Characterization
TOI-2876 b is a confirmed gas giant exoplanet orbiting the star TOI-2876, located approximately 736.3 light-years (225.74 parsecs) from the Solar System. First announced in 2025 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 1.0249% across the stellar disk), this world measures 9.64 Earth radii (0.86 Jupiter radii) and has a measured mass of 54.031 Earth masses (0.17 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.33 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.58 g⊕ (5.69 m/s²), and an escape velocity of 26.5 km/s.
In its orbital architecture around TOI-2876, TOI-2876 b completes one full revolution every 6.3 Earth days at a semi-major axis of 0.0654 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 112.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.13 carries the world between 0.0569 AU at periapsis and 0.0739 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 929 K (+656°C / +1213°F) and receiving 124.20 S⊕ (~169,036 W/m²), TOI-2876 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2876 is classified as a stellar host with an effective photospheric temperature of 5,271 K, a radius of 0.873 R☉, a mass of 0.939 M☉, an estimated bolometric luminosity of 0.528 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.8 Gyr and a metallicity of [Fe/H] = 0.353 dex (metal-rich relative to the Sun). From Earth, TOI-2876 shines at apparent V-band magnitude 12.401 (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-2876 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,271 K |
| Stellar Radius | 0.8730 R☉ |
| Stellar Mass | 0.9390 M☉ |
| Bolometric Luminosity | 0.528 L☉ |
| Metallicity [Fe/H] | 0.353 dex |
| Stellar Age | 3.800 Gyr |
| Apparent Magnitude | V: 12.401 · G: 12.257 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.065400 AU |
| Orbital Period | 6.3 days |
| Mean Orbital Velocity | 112.9 km/s |
| Orbital Eccentricity (e) | 0.13000 |
| Orbital Inclination (i) | 87.1300° |
| Mean Bulk Density | 0.33 g/cm³ (26.5 km/s vesc) |
| Insolation Flux | 124.2000 S⊕ (~169,036 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 736.300 LY (225.744 pc) |