HIP 70849 b
Astrophysical Synthesis & Habitability Characterization
HIP 70849 b is a confirmed gas giant exoplanet orbiting the star HIP 70849, located approximately 78.5 light-years (24.06 parsecs) from the Solar System. First announced in 2011 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.9 Earth radii (1.15 Jupiter radii) and has a measured mass of 1430.228 Earth masses (4.5 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.67 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 8.59 g⊕ (84.24 m/s²), and an escape velocity of 117.8 km/s.
In its orbital architecture around HIP 70849, HIP 70849 b completes one full revolution every 3649 Earth days (9.99Julian years) at a semi-major axis of 3.99 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 11.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.65, swinging from 1.3965 AU at periapsis out to 6.5835 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 79 K (-194°C / -317°F) and an incident flux of 0.01 S⊕ (~8 W/m²), surface water and volatile species on HIP 70849 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HIP 70849 is classified as an orange K-type star of spectral type K7 V with an effective photospheric temperature of 4,105 K, a radius of 0.6331 R☉, a mass of 0.65 M☉, an estimated bolometric luminosity of 0.102 L☉. Stellar evolution modeling indicates an estimated stellar age of 3 Gyr. From Earth, HIP 70849 shines at apparent V-band magnitude 10.421 (faint and requiring research-grade or CCD telescopic photometry) 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 | HIP 70849 |
| Spectral Type | K7 V |
| Effective Temp (Teff) | 4,105 K |
| Stellar Radius | 0.6331 R☉ |
| Stellar Mass | 0.6500 M☉ |
| Bolometric Luminosity | 0.102 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 3.000 Gyr |
| Apparent Magnitude | V: 10.421 · G: 9.698 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.990000 AU |
| Orbital Period | 3649 days |
| Mean Orbital Velocity | 11.9 km/s |
| Orbital Eccentricity (e) | 0.65000 |
| Orbital Inclination (i) | 96.0000° |
| Mean Bulk Density | 3.67 g/cm³ (117.8 km/s vesc) |
| Insolation Flux | 0.0056 S⊕ (~8 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 78.500 LY (24.057 pc) |