HD 142245 b
Astrophysical Synthesis & Habitability Characterization
HD 142245 b is a confirmed gas giant exoplanet orbiting the star HD 142245, located approximately 317.1 light-years (97.23 parsecs) from the Solar System. First announced in 2011 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.1 Earth radii (1.17 Jupiter radii) and has a measured mass of 975.738 Earth masses (3.07 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.39 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 5.69 g⊕ (55.8 m/s²), and an escape velocity of 96.5 km/s.
In its orbital architecture around HD 142245, HD 142245 b completes one full revolution every 1299 Earth days (3.56Julian years) at a semi-major axis of 2.78 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 23.3 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.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.100 R⊕, HD 142245 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star HD 142245 is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 4,922 K, a radius of 4.63 R☉, a mass of 3.5 M☉, an estimated bolometric luminosity of 11.288 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.3 Gyr and a metallicity of [Fe/H] = 0.17 dex (metal-rich relative to the Sun). From Earth, HD 142245 shines at apparent V-band magnitude 7.46 (accessible to binoculars and small amateur telescopes) 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 142245 |
| Spectral Type | K0 |
| Effective Temp (Teff) | 4,922 K |
| Stellar Radius | 4.6300 R☉ |
| Stellar Mass | 3.5000 M☉ |
| Bolometric Luminosity | 11.288 L☉ |
| Metallicity [Fe/H] | 0.170 dex |
| Stellar Age | 2.300 Gyr |
| Apparent Magnitude | V: 7.460 · G: 7.189 |
| System Architecture | 3 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.780000 AU |
| Orbital Period | 1299 days |
| Mean Orbital Velocity | 23.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.39 g/cm³ (96.5 km/s vesc) |
| Insolation Flux | 1.7468 S⊕ (~2,377 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 317.100 LY (97.231 pc) |