TIC 172900988 b
Astrophysical Synthesis & Habitability Characterization
TIC 172900988 b is a confirmed gas giant exoplanet orbiting the star TIC 172900988 Aa, located approximately 818.5 light-years (250.96 parsecs) from the Solar System. First announced in 2021 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.5552% across the stellar disk), this world measures 11.25 Earth radii (1 Jupiter radii) and has a measured mass of 942 Earth masses (2.96 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.65 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 7.44 g⊕ (72.96 m/s²), and an escape velocity of 102.4 km/s.
In its orbital architecture around TIC 172900988 Aa, TIC 172900988 b completes one full revolution every 200.452 Earth days at a semi-major axis of 0.90281 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 49 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.0271 (ranging from 0.8783 AU at periapsis to 0.9273 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 361 K (+88°C / +190°F) and receiving 5.75 S⊕ (~7,829 W/m²), TIC 172900988 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TIC 172900988 Aa is classified as a warm F-type star of spectral type F9 with an effective photospheric temperature of 6,050 K, a radius of 1.3842 R☉, a mass of 1.2384 M☉, an estimated bolometric luminosity of 2.303 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.1 Gyr and a metallicity of [Fe/H] = 0.34 dex (metal-rich relative to the Sun). From Earth, TIC 172900988 Aa shines at apparent V-band magnitude 10.141 (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 | TIC 172900988 Aa |
| Spectral Type | F9 |
| Effective Temp (Teff) | 6,050 K |
| Stellar Radius | 1.3842 R☉ |
| Stellar Mass | 1.2384 M☉ |
| Bolometric Luminosity | 2.303 L☉ |
| Metallicity [Fe/H] | 0.340 dex |
| Stellar Age | 3.100 Gyr |
| Apparent Magnitude | V: 10.141 · G: 10.048 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.902810 AU |
| Orbital Period | 200.452 days |
| Mean Orbital Velocity | 49 km/s |
| Orbital Eccentricity (e) | 0.02710 |
| Orbital Inclination (i) | 91.7900° |
| Mean Bulk Density | 3.65 g/cm³ (102.4 km/s vesc) |
| Insolation Flux | 5.7522 S⊕ (~7,829 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 818.500 LY (250.956 pc) |