HIP 97166 b
Astrophysical Synthesis & Habitability Characterization
HIP 97166 b is a confirmed sub-neptune exoplanet orbiting the star HIP 97166, located approximately 215.1 light-years (65.95 parsecs) from the Solar System. First announced in 2021 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.073% across the stellar disk), this world measures 2.48 Earth radii and has a measured mass of 19.1 Earth masses. Combining its mass and radius yields a mean bulk density of 6.9 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 3.11 g⊕ (30.5 m/s²), and an escape velocity of 31 km/s.
In its orbital architecture around HIP 97166, HIP 97166 b completes one full revolution every 10.289 Earth days at a semi-major axis of 0.091 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 96.2 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.29, swinging from 0.0646 AU at periapsis out to 0.1174 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 702 K (+429°C / +804°F) and receiving 9.07 S⊕ (~12,342 W/m²), HIP 97166 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HIP 97166 is classified as an orange K-type star of spectral type K0 V with an effective photospheric temperature of 5,216 K, a radius of 0.8418 R☉, a mass of 0.9342 M☉, an estimated bolometric luminosity of 0.471 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.2 Gyr and a metallicity of [Fe/H] = 0.248 dex (metal-rich relative to the Sun). From Earth, HIP 97166 shines at apparent V-band magnitude 9.92 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HIP 97166 system is a multi-planet architecture hosting 2 confirmed worlds, with HIP 97166 b sharing its stellar neighborhood alongside HIP 97166 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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 97166 |
| Spectral Type | K0 V |
| Effective Temp (Teff) | 5,216 K |
| Stellar Radius | 0.8418 R☉ |
| Stellar Mass | 0.9342 M☉ |
| Bolometric Luminosity | 0.471 L☉ |
| Metallicity [Fe/H] | 0.248 dex |
| Stellar Age | 1.200 Gyr |
| Apparent Magnitude | V: 9.920 · G: 9.684 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.091000 AU |
| Orbital Period | 10.289 days |
| Mean Orbital Velocity | 96.2 km/s |
| Orbital Eccentricity (e) | 0.29000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 6.9 g/cm³ (31 km/s vesc) |
| Insolation Flux | 9.0686 S⊕ (~12,342 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 215.100 LY (65.950 pc) |