TOI-7189 b
Astrophysical Synthesis & Habitability Characterization
TOI-7189 b is a confirmed gas giant exoplanet orbiting the star TOI-7189, located approximately 626.5 light-years (192.09 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 2.859% across the stellar disk), this world measures 10.9 Earth radii (0.97 Jupiter radii) and has a measured mass of 159.04 Earth masses (0.5 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.68 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.34 g⊕ (13.14 m/s²), and an escape velocity of 42.7 km/s.
In its orbital architecture around TOI-7189, TOI-7189 b completes one full revolution every 2.891 Earth days at a semi-major axis of 0.03294 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 124 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.0601 carries the world between 0.031 AU at periapsis and 0.0349 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 738 K (+465°C / +869°F) and receiving 49.30 S⊕ (~67,097 W/m²), TOI-7189 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-7189 is classified as a low-mass red dwarf of spectral type M1 V with an effective photospheric temperature of 3,775 K, a radius of 0.591 R☉, a mass of 0.612 M☉, an estimated bolometric luminosity of 0.064 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.47 dex (metal-rich relative to the Sun). From Earth, TOI-7189 shines at apparent V-band magnitude 15.88 (faint and requiring research-grade or CCD telescopic photometry) in the Northern 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-7189 |
| Spectral Type | M1 V |
| Effective Temp (Teff) | 3,775 K |
| Stellar Radius | 0.5910 R☉ |
| Stellar Mass | 0.6120 M☉ |
| Bolometric Luminosity | 0.064 L☉ |
| Metallicity [Fe/H] | 0.470 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 15.880 · G: 14.903 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.032940 AU |
| Orbital Period | 2.891 days |
| Mean Orbital Velocity | 124 km/s |
| Orbital Eccentricity (e) | 0.06010 |
| Orbital Inclination (i) | 88.4100° |
| Mean Bulk Density | 0.68 g/cm³ (42.7 km/s vesc) |
| Insolation Flux | 49.3000 S⊕ (~67,097 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 626.500 LY (192.090 pc) |