TOI-2981 b
Astrophysical Synthesis & Habitability Characterization
TOI-2981 b is a confirmed gas giant exoplanet orbiting the star TOI-2981, located approximately 1721.4 light-years (527.79 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 1.2939% across the stellar disk), this world measures 13.4 Earth radii (1.2 Jupiter radii) and has a measured mass of 638 Earth masses (2.01 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.46 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.55 g⊕ (34.81 m/s²), and an escape velocity of 77.2 km/s.
In its orbital architecture around TOI-2981, TOI-2981 b completes one full revolution every 3.602 Earth days at a semi-major axis of 0.048 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 145 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.035 (ranging from 0.0463 AU at periapsis to 0.0497 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1358 K (+1085°C / +1985°F) and receiving 556.62 S⊕ (~757,554 W/m²), TOI-2981 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2981 is classified as a stellar host with an effective photospheric temperature of 5,940 K, a radius of 1.08 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.303 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.5 Gyr and a metallicity of [Fe/H] = -0.11 dex (metal-poor relative to the Sun). From Earth, TOI-2981 shines at apparent V-band magnitude 13.361 (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-2981 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,940 K |
| Stellar Radius | 1.0800 R☉ |
| Stellar Mass | 1.0300 M☉ |
| Bolometric Luminosity | 1.303 L☉ |
| Metallicity [Fe/H] | -0.110 dex |
| Stellar Age | 4.500 Gyr |
| Apparent Magnitude | V: 13.361 · G: 13.187 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.048000 AU |
| Orbital Period | 3.602 days |
| Mean Orbital Velocity | 145 km/s |
| Orbital Eccentricity (e) | 0.03500 |
| Orbital Inclination (i) | 87.9800° |
| Mean Bulk Density | 1.46 g/cm³ (77.2 km/s vesc) |
| Insolation Flux | 556.6160 S⊕ (~757,554 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1721.400 LY (527.789 pc) |