HD 93351 b
Astrophysical Synthesis & Habitability Characterization
HD 93351 b is a confirmed super-earth exoplanet orbiting the star HD 93351, located approximately 183.2 light-years (56.16 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 1.69 Earth radii and has a measured mass of 3.496 Earth masses. Combining its mass and radius yields a mean bulk density of 3.99 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 16.1 km/s.
In its orbital architecture around HD 93351, HD 93351 b completes one full revolution every 2.459 Earth days at a semi-major axis of 0.035 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 154.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.549, swinging from 0.0158 AU at periapsis out to 0.0542 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1331 K (+1058°C / +1936°F) and receiving 522.58 S⊕ (~711,238 W/m²), HD 93351 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 93351 is classified as a stellar host with an effective photospheric temperature of 5,408 K, a radius of 0.9114 R☉, a mass of 0.94 M☉, an estimated bolometric luminosity of 0.637 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.23 dex (metal-poor relative to the Sun). From Earth, HD 93351 shines at apparent V-band magnitude 9.12 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 93351 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 93351 b sharing its stellar neighborhood alongside HD 93351 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 93351 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,408 K |
| Stellar Radius | 0.9114 R☉ |
| Stellar Mass | 0.9400 M☉ |
| Bolometric Luminosity | 0.637 L☉ |
| Metallicity [Fe/H] | -0.230 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 9.120 · G: 8.947 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.035000 AU |
| Orbital Period | 2.459 days |
| Mean Orbital Velocity | 154.8 km/s |
| Orbital Eccentricity (e) | 0.54900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 3.99 g/cm³ (16.1 km/s vesc) |
| Insolation Flux | 522.5845 S⊕ (~711,238 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 183.200 LY (56.163 pc) |