HD 715 b
Astrophysical Synthesis & Habitability Characterization
HD 715 b is a confirmed gas giant exoplanet orbiting the star HD 715, located approximately 545.5 light-years (167.25 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 0.1935% across the stellar disk), this world measures 11.994 Earth radii (1.07 Jupiter radii) and has a measured mass of 201.821 Earth masses (0.63 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.64 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.4 g⊕ (13.73 m/s²), and an escape velocity of 45.9 km/s.
In its orbital architecture around HD 715, HD 715 b completes one full revolution every 56.4 Earth days at a semi-major axis of 0.336 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 64.8 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.21 carries the world between 0.2654 AU at periapsis and 0.4066 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 798 K (+525°C / +977°F) and receiving 67.30 S⊕ (~91,595 W/m²), HD 715 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 715 is classified as a warm F-type star of spectral type F8 IV with an effective photospheric temperature of 6,070 K, a radius of 2.5 R☉, a mass of 1.6 M☉, an estimated bolometric luminosity of 7.612 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.1 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, HD 715 shines at apparent V-band magnitude 8.703 (accessible to binoculars and small amateur telescopes) 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 | HD 715 |
| Spectral Type | F8 IV |
| Effective Temp (Teff) | 6,070 K |
| Stellar Radius | 2.5000 R☉ |
| Stellar Mass | 1.6000 M☉ |
| Bolometric Luminosity | 7.612 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 2.100 Gyr |
| Apparent Magnitude | V: 8.703 · G: 8.579 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.336000 AU |
| Orbital Period | 56.4 days |
| Mean Orbital Velocity | 64.8 km/s |
| Orbital Eccentricity (e) | 0.21000 |
| Orbital Inclination (i) | 88.9100° |
| Mean Bulk Density | 0.64 g/cm³ (45.9 km/s vesc) |
| Insolation Flux | 67.3000 S⊕ (~91,595 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 545.500 LY (167.253 pc) |