Kepler-49 d
Astrophysical Synthesis & Habitability Characterization
Kepler-49 d is a confirmed super-earth exoplanet orbiting the star Kepler-49, located approximately 1015.1 light-years (311.22 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0689% across the stellar disk), this world measures 1.6 Earth radii and has a measured mass of 235.982 Earth masses (0.74 Jupiter masses). Combining its mass and radius yields a mean bulk density of 317.68 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 92.18 g⊕ (903.98 m/s²), and an escape velocity of 135.8 km/s.
In its orbital architecture around Kepler-49, Kepler-49 d completes one full revolution every 2.577 Earth days at a semi-major axis of 0.031 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 130.9 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 717 K (+444°C / +831°F) and receiving 64.39 S⊕ (~87,635 W/m²), Kepler-49 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-49 is classified as a low-mass red dwarf of spectral type M1 V with an effective photospheric temperature of 4,252 K, a radius of 0.559 R☉, a mass of 0.549 M☉, an estimated bolometric luminosity of 0.092 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-49 shines at apparent V-band magnitude 15.655 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-49 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-49 d sharing its stellar neighborhood alongside Kepler-49 b, Kepler-49 c, Kepler-49 e.
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-49 |
| Spectral Type | M1 V |
| Effective Temp (Teff) | 4,252 K |
| Stellar Radius | 0.5590 R☉ |
| Stellar Mass | 0.5490 M☉ |
| Bolometric Luminosity | 0.092 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 2.880 Gyr |
| Apparent Magnitude | V: 15.655 · G: 15.229 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.031000 AU |
| Orbital Period | 2.577 days |
| Mean Orbital Velocity | 130.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.1400° |
| Mean Bulk Density | 317.68 g/cm³ (135.8 km/s vesc) |
| Insolation Flux | 64.3900 S⊕ (~87,635 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1015.100 LY (311.222 pc) |