Kepler-1530 d
Astrophysical Synthesis & Habitability Characterization
Kepler-1530 d is a confirmed sub-neptune exoplanet orbiting the star Kepler-1530, located approximately 1597.8 light-years (489.88 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0532% across the stellar disk), this world measures 3.279 Earth radii (0.29 Jupiter radii) and has a measured mass of 10.8 Earth masses. Combining its mass and radius yields a mean bulk density of 1.69 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1 g⊕ (9.81 m/s²), and an escape velocity of 20.3 km/s.
In its orbital architecture around Kepler-1530, Kepler-1530 d completes one full revolution every 9.208 Earth days at a semi-major axis of 0.08276 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 97.8 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 972 K (+699°C / +1290°F) and receiving 69.20 S⊕ (~94,181 W/m²), Kepler-1530 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1530 is classified as a stellar host with an effective photospheric temperature of 5,678 K, a radius of 1.303 R☉, a mass of 1.015 M☉, an estimated bolometric luminosity of 1.583 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.17 Gyr and a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, Kepler-1530 shines at apparent V-band magnitude 14.15 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1530 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-1530 d sharing its stellar neighborhood alongside Kepler-1530 b, Kepler-1530 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-1530 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,678 K |
| Stellar Radius | 1.3030 R☉ |
| Stellar Mass | 1.0150 M☉ |
| Bolometric Luminosity | 1.583 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | 1.170 Gyr |
| Apparent Magnitude | V: 14.150 · G: 14.006 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.082760 AU |
| Orbital Period | 9.208 days |
| Mean Orbital Velocity | 97.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.3000° |
| Mean Bulk Density | 1.69 g/cm³ (20.3 km/s vesc) |
| Insolation Flux | 69.2000 S⊕ (~94,181 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1597.800 LY (489.876 pc) |