HIP 116454 b
Astrophysical Synthesis & Habitability Characterization
HIP 116454 b is a confirmed sub-neptune exoplanet orbiting the star HIP 116454, located approximately 203.7 light-years (62.45 parsecs) from the Solar System. First announced in 2014 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0892% across the stellar disk), this world measures 2.469 Earth radii and has a measured mass of 9.7 Earth masses. Combining its mass and radius yields a mean bulk density of 3.55 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.59 g⊕ (15.59 m/s²), and an escape velocity of 22.2 km/s.
In its orbital architecture around HIP 116454, HIP 116454 b completes one full revolution every 9.1 Earth days at a semi-major axis of 0.0792 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 94.7 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.215 carries the world between 0.0622 AU at periapsis and 0.0962 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 753 K (+480°C / +896°F) and receiving 51.29 S⊕ (~69,800 W/m²), HIP 116454 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HIP 116454 is classified as an orange K-type star of spectral type K1 with an effective photospheric temperature of 5,048 K, a radius of 0.758 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.335 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.5 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, HIP 116454 shines at apparent V-band magnitude 10.19 (faint and requiring research-grade or CCD telescopic photometry) 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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 116454 |
| Spectral Type | K1 |
| Effective Temp (Teff) | 5,048 K |
| Stellar Radius | 0.7580 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.335 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 5.500 Gyr |
| Apparent Magnitude | V: 10.190 · G: 9.932 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.079200 AU |
| Orbital Period | 9.1 days |
| Mean Orbital Velocity | 94.7 km/s |
| Orbital Eccentricity (e) | 0.21500 |
| Orbital Inclination (i) | 88.9100° |
| Mean Bulk Density | 3.55 g/cm³ (22.2 km/s vesc) |
| Insolation Flux | 51.2858 S⊕ (~69,800 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 203.700 LY (62.449 pc) |