eps Ind A b
Astrophysical Synthesis & Habitability Characterization
eps Ind A b is a confirmed gas giant exoplanet orbiting the star eps Ind A, located approximately 11.9 light-years (3.64 parsecs) from the Solar System. First announced in 2019 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.7 Earth radii (1.13 Jupiter radii) and has a measured mass of 2065.885 Earth masses (6.5 Jupiter masses). Combining its mass and radius yields a mean bulk density of 5.56 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 12.81 g⊕ (125.62 m/s²), and an escape velocity of 142.7 km/s.
In its orbital architecture around eps Ind A, eps Ind A b completes one full revolution every 25450 Earth days (69.68Julian years) at a semi-major axis of 15.76 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 6.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.25, swinging from 11.82 AU at periapsis out to 19.7 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.700 R⊕, eps Ind A 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 eps Ind A is classified as an orange K-type star of spectral type K5 V with an effective photospheric temperature of 4,700 K, a radius of 0.713 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.223 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.48 Gyr and a metallicity of [Fe/H] = -0.17 dex (metal-poor relative to the Sun). From Earth, eps Ind A shines at apparent V-band magnitude 4.69 (visible to the unaided human eye under dark skies) in the Southern 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | eps Ind A |
| Spectral Type | K5 V |
| Effective Temp (Teff) | 4,700 K |
| Stellar Radius | 0.7130 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.223 L☉ |
| Metallicity [Fe/H] | -0.170 dex |
| Stellar Age | 3.480 Gyr |
| Apparent Magnitude | V: 4.690 · G: 4.346 |
| System Architecture | 3 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 15.760000 AU |
| Orbital Period | 25450 days |
| Mean Orbital Velocity | 6.7 km/s |
| Orbital Eccentricity (e) | 0.25000 |
| Orbital Inclination (i) | 102.1800° |
| Mean Bulk Density | 5.56 g/cm³ (142.7 km/s vesc) |
| Insolation Flux | 0.0010 S⊕ (~1 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 11.900 LY (3.639 pc) |