Kepler-449 b
Astrophysical Synthesis & Habitability Characterization
Kepler-449 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-449, located approximately 789.1 light-years (241.95 parsecs) from the Solar System. First announced in 2015 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0165% across the stellar disk), this world measures 2.056 Earth radii and has a measured mass of 4.88 Earth masses. Combining its mass and radius yields a mean bulk density of 3.1 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.15 g⊕ (11.28 m/s²), and an escape velocity of 17.2 km/s.
In its orbital architecture around Kepler-449, Kepler-449 b completes one full revolution every 12.582 Earth days at a semi-major axis of 0.1027 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 88.8 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.03 (ranging from 0.0996 AU at periapsis to 0.1058 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 917 K (+644°C / +1191°F) and receiving 167.41 S⊕ (~227,845 W/m²), Kepler-449 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-449 is classified as a stellar host with an effective photospheric temperature of 5,649 K, a radius of 1.467 R☉, a mass of 1.02 M☉, an estimated bolometric luminosity of 1.966 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.77 Gyr and a metallicity of [Fe/H] = -0.165 dex (metal-poor relative to the Sun). From Earth, Kepler-449 shines at apparent V-band magnitude 11.448 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-449 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-449 b sharing its stellar neighborhood alongside Kepler-449 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-449 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,649 K |
| Stellar Radius | 1.4670 R☉ |
| Stellar Mass | 1.0200 M☉ |
| Bolometric Luminosity | 1.966 L☉ |
| Metallicity [Fe/H] | -0.165 dex |
| Stellar Age | 9.770 Gyr |
| Apparent Magnitude | V: 11.448 · G: 11.226 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.102700 AU |
| Orbital Period | 12.582 days |
| Mean Orbital Velocity | 88.8 km/s |
| Orbital Eccentricity (e) | 0.03000 |
| Orbital Inclination (i) | 89.8300° |
| Mean Bulk Density | 3.1 g/cm³ (17.2 km/s vesc) |
| Insolation Flux | 167.4100 S⊕ (~227,845 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 789.100 LY (241.949 pc) |