Kepler-1408 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1408 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1408, located approximately 1745.1 light-years (535.05 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0037% across the stellar disk), this world measures 0.89 Earth radii and has a measured mass of 0.64 Earth masses. Combining its mass and radius yields a mean bulk density of 5.01 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.81 g⊕ (7.94 m/s²), and an escape velocity of 9.5 km/s.
In its orbital architecture around Kepler-1408, Kepler-1408 b completes one full revolution every 2.998 Earth days at a semi-major axis of 0.04218 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 153.1 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 1616 K (+1343°C / +2449°F) and receiving 1,982.27 S⊕ (~2,697,867 W/m²), Kepler-1408 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1408 is classified as a stellar host with an effective photospheric temperature of 6,170 K, a radius of 1.35 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 2.37 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.57 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-1408 shines at apparent V-band magnitude 12.124 (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-1408 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,170 K |
| Stellar Radius | 1.3500 R☉ |
| Stellar Mass | 1.2100 M☉ |
| Bolometric Luminosity | 2.37 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 2.570 Gyr |
| Apparent Magnitude | V: 12.124 · G: 11.962 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.042180 AU |
| Orbital Period | 2.998 days |
| Mean Orbital Velocity | 153.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.2400° |
| Mean Bulk Density | 5.01 g/cm³ (9.5 km/s vesc) |
| Insolation Flux | 1982.2680 S⊕ (~2,697,867 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1745.100 LY (535.048 pc) |