TrES-4 b

Astrophysical Synthesis & Habitability Characterization

TrES-4 b is a confirmed gas giant exoplanet orbiting the star TrES-4, located approximately 1682.9 light-years (515.98 parsecs) from the Solar System. First announced in 2007 by TrES using the Transit detection technique (producing an estimated primary transit depth of 0.9933% across the stellar disk), this world measures 18.046 Earth radii (1.61 Jupiter radii) and has a measured mass of 247.907 Earth masses (0.78 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.23 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.76 g⊕ (7.45 m/s²), and an escape velocity of 41.5 km/s.

In its orbital architecture around TrES-4, TrES-4 b completes one full revolution every 3.554 Earth days at a semi-major axis of 0.05084 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 155.6 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 1778 K (+1505°C / +2741°F) and receiving 2,276.30 S⊕ (~3,098,037 W/m²), TrES-4 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star TrES-4 is classified as a warm F-type star of spectral type F8 V with an effective photospheric temperature of 6,200 K, a radius of 1.66 R☉, a mass of 1.08 M☉, an estimated bolometric luminosity of 3.653 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.2 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, TrES-4 shines at apparent V-band magnitude 11.932 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

Discovery Facility: TrES · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).