Kepler-1655 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1655 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1655, located approximately 695.6 light-years (213.26 parsecs) from the Solar System. First announced in 2018 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0388% across the stellar disk), this world measures 2.213 Earth radii and has a measured mass of 5.4 Earth masses. Combining its mass and radius yields a mean bulk density of 2.75 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 17.5 km/s.
In its orbital architecture around Kepler-1655, Kepler-1655 b completes one full revolution every 11.873 Earth days at a semi-major axis of 0.1029 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 94.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.19 carries the world between 0.0833 AU at periapsis and 0.1225 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 938 K (+665°C / +1229°F) and receiving 129.10 S⊕ (~175,705 W/m²), Kepler-1655 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1655 is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 6,148 K, a radius of 1.03 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.36 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.56 Gyr and a metallicity of [Fe/H] = -0.24 dex (metal-poor relative to the Sun). From Earth, Kepler-1655 shines at apparent V-band magnitude 11.045 (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-1655 |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 6,148 K |
| Stellar Radius | 1.0300 R☉ |
| Stellar Mass | 1.0300 M☉ |
| Bolometric Luminosity | 1.36 L☉ |
| Metallicity [Fe/H] | -0.240 dex |
| Stellar Age | 2.560 Gyr |
| Apparent Magnitude | V: 11.045 · G: 11.014 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.102900 AU |
| Orbital Period | 11.873 days |
| Mean Orbital Velocity | 94.3 km/s |
| Orbital Eccentricity (e) | 0.19000 |
| Orbital Inclination (i) | 87.6200° |
| Mean Bulk Density | 2.75 g/cm³ (17.5 km/s vesc) |
| Insolation Flux | 129.1000 S⊕ (~175,705 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 695.600 LY (213.260 pc) |