Kepler-1772 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1772 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1772, located approximately 2842.7 light-years (871.56 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0695% across the stellar disk), this world measures 2.686 Earth radii and has a measured mass of 7.68 Earth masses. Combining its mass and radius yields a mean bulk density of 2.19 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 18.9 km/s.
In its orbital architecture around Kepler-1772, Kepler-1772 b completes one full revolution every 3.215 Earth days at a semi-major axis of 0.04391 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 148.6 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 1155 K (+882°C / +1620°F) and receiving 1,485.00 S⊕ (~2,021,085 W/m²), Kepler-1772 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1772 is classified as a stellar host with an effective photospheric temperature of 5,541 K, a radius of 0.934 R☉, a mass of 0.942 M☉, an estimated bolometric luminosity of 0.738 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.94 Gyr and a metallicity of [Fe/H] = 0.12 dex (metal-rich relative to the Sun). From Earth, Kepler-1772 shines at apparent V-band magnitude 13.546 (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-1772 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,541 K |
| Stellar Radius | 0.9340 R☉ |
| Stellar Mass | 0.9420 M☉ |
| Bolometric Luminosity | 0.738 L☉ |
| Metallicity [Fe/H] | 0.120 dex |
| Stellar Age | 7.940 Gyr |
| Apparent Magnitude | V: 13.546 · G: 13.395 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.043910 AU |
| Orbital Period | 3.215 days |
| Mean Orbital Velocity | 148.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 63.9900° |
| Mean Bulk Density | 2.19 g/cm³ (18.9 km/s vesc) |
| Insolation Flux | 1485.0000 S⊕ (~2,021,085 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2842.700 LY (871.564 pc) |