Kepler-773 b
Astrophysical Synthesis & Habitability Characterization
Kepler-773 b is a confirmed super-earth exoplanet orbiting the star Kepler-773, located approximately 1784.2 light-years (547.03 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0168% across the stellar disk), this world measures 1.43 Earth radii and has a measured mass of 2.63 Earth masses. Combining its mass and radius yields a mean bulk density of 4.96 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 15.2 km/s.
In its orbital architecture around Kepler-773, Kepler-773 b completes one full revolution every 3.749 Earth days at a semi-major axis of 0.04682 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 135.9 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 1160 K (+887°C / +1629°F) and receiving 490.71 S⊕ (~667,852 W/m²), Kepler-773 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-773 is classified as a stellar host with an effective photospheric temperature of 5,850 K, a radius of 1.01 R☉, a mass of 1.04 M☉, an estimated bolometric luminosity of 1.072 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.82 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-773 shines at apparent V-band magnitude 13.387 (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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-773 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,850 K |
| Stellar Radius | 1.0100 R☉ |
| Stellar Mass | 1.0400 M☉ |
| Bolometric Luminosity | 1.072 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | 2.820 Gyr |
| Apparent Magnitude | V: 13.387 · G: 13.280 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.046820 AU |
| Orbital Period | 3.749 days |
| Mean Orbital Velocity | 135.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 80.2400° |
| Mean Bulk Density | 4.96 g/cm³ (15.2 km/s vesc) |
| Insolation Flux | 490.7070 S⊕ (~667,852 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1784.200 LY (547.026 pc) |