HD 156098 c
Astrophysical Synthesis & Habitability Characterization
HD 156098 c is a confirmed gas giant exoplanet orbiting the star HD 156098, located approximately 157.4 light-years (48.25 parsecs) from the Solar System. First announced in 2022 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.8 Earth radii (1.14 Jupiter radii) and has a measured mass of 1661.607 Earth masses (5.23 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.37 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 10.14 g⊕ (99.44 m/s²), and an escape velocity of 127.4 km/s.
In its orbital architecture around HD 156098, HD 156098 c completes one full revolution every 7841.584 Earth days (21.47Julian years) at a semi-major axis of 8.415 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 11.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.391, swinging from 5.1247 AU at periapsis out to 11.7053 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 177 K (-96°C / -141°F) and an incident flux of 0.16 S⊕ (~223 W/m²), surface water and volatile species on HD 156098 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 156098 is classified as a stellar host with an effective photospheric temperature of 6,419 K, a radius of 2.7572 R☉, a mass of 1.29 M☉, an estimated bolometric luminosity of 11.58 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.12 dex (metal-rich relative to the Sun). From Earth, HD 156098 shines at apparent V-band magnitude 5.53 (visible to the unaided human eye under dark skies) in the Southern celestial hemisphere. The HD 156098 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 156098 c sharing its stellar neighborhood alongside HD 156098 b.
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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 156098 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,419 K |
| Stellar Radius | 2.7572 R☉ |
| Stellar Mass | 1.2900 M☉ |
| Bolometric Luminosity | 11.58 L☉ |
| Metallicity [Fe/H] | 0.120 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 5.530 · G: 5.412 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 8.415000 AU |
| Orbital Period | 7841.584 days |
| Mean Orbital Velocity | 11.7 km/s |
| Orbital Eccentricity (e) | 0.39100 |
| Orbital Inclination (i) | 23.4620° |
| Mean Bulk Density | 4.37 g/cm³ (127.4 km/s vesc) |
| Insolation Flux | 0.1642 S⊕ (~223 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 157.400 LY (48.249 pc) |