Kepler-55 e
Astrophysical Synthesis & Habitability Characterization
Kepler-55 e is a confirmed super-earth exoplanet orbiting the star Kepler-55, located approximately 1887.8 light-years (578.8 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0527% across the stellar disk), this world measures 1.55 Earth radii and has a measured mass of 3.02 Earth masses. Combining its mass and radius yields a mean bulk density of 4.47 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.26 g⊕ (12.36 m/s²), and an escape velocity of 15.6 km/s.
In its orbital architecture around Kepler-55, Kepler-55 e completes one full revolution every 4.618 Earth days at a semi-major axis of 0.048 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 113.1 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 728 K (+455°C / +851°F) and receiving 73.16 S⊕ (~99,567 W/m²), Kepler-55 e orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-55 is classified as a stellar host with an effective photospheric temperature of 4,503 K, a radius of 0.619 R☉, a mass of 0.631 M☉, an estimated bolometric luminosity of 0.141 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.34 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-55 shines at apparent V-band magnitude 15.746 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-55 system is a multi-planet architecture hosting 5 confirmed worlds, with Kepler-55 e sharing its stellar neighborhood alongside Kepler-55 d, Kepler-55 f, Kepler-55 b, Kepler-55 c.
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-55 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,503 K |
| Stellar Radius | 0.6190 R☉ |
| Stellar Mass | 0.6310 M☉ |
| Bolometric Luminosity | 0.141 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 2.340 Gyr |
| Apparent Magnitude | V: 15.746 · G: 15.781 |
| System Architecture | 1 Star, 5 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.048000 AU |
| Orbital Period | 4.618 days |
| Mean Orbital Velocity | 113.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.9900° |
| Mean Bulk Density | 4.47 g/cm³ (15.6 km/s vesc) |
| Insolation Flux | 73.1570 S⊕ (~99,567 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1887.800 LY (578.796 pc) |