TOI-2989 b
Astrophysical Synthesis & Habitability Characterization
TOI-2989 b is a confirmed gas giant exoplanet orbiting the star TOI-2989, located approximately 638.6 light-years (195.8 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 2.2934% across the stellar disk), this world measures 12.554 Earth radii (1.12 Jupiter radii) and has a measured mass of 953.485 Earth masses (3 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.66 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 6.05 g⊕ (59.33 m/s²), and an escape velocity of 97.5 km/s.
In its orbital architecture around TOI-2989, TOI-2989 b completes one full revolution every 3.123 Earth days at a semi-major axis of 0.0384 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 133.8 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 1001 K (+728°C / +1342°F) and receiving 124.00 S⊕ (~168,764 W/m²), TOI-2989 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2989 is classified as an orange K-type star of spectral type K4 V with an effective photospheric temperature of 4,672 K, a radius of 0.76 R☉, a mass of 0.77 M☉, an estimated bolometric luminosity of 0.247 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, TOI-2989 shines at apparent V-band magnitude 13.859 (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-2989 |
| Spectral Type | K4 V |
| Effective Temp (Teff) | 4,672 K |
| Stellar Radius | 0.7600 R☉ |
| Stellar Mass | 0.7700 M☉ |
| Bolometric Luminosity | 0.247 L☉ |
| Metallicity [Fe/H] | -0.040 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 13.859 · G: 13.476 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.038400 AU |
| Orbital Period | 3.123 days |
| Mean Orbital Velocity | 133.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.1000° |
| Mean Bulk Density | 2.66 g/cm³ (97.5 km/s vesc) |
| Insolation Flux | 124.0000 S⊕ (~168,764 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 638.600 LY (195.795 pc) |