HD 63935 b
Astrophysical Synthesis & Habitability Characterization
HD 63935 b is a confirmed sub-neptune exoplanet orbiting the star HD 63935, located approximately 159.7 light-years (48.97 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 0.0776% across the stellar disk), this world measures 2.916 Earth radii and has a measured mass of 10.5 Earth masses. Combining its mass and radius yields a mean bulk density of 2.34 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 21.2 km/s.
In its orbital architecture around HD 63935, HD 63935 b completes one full revolution every 9.059 Earth days at a semi-major axis of 0.083 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 99.7 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 825 K (+552°C / +1026°F) and receiving 115.60 S⊕ (~157,332 W/m²), HD 63935 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 63935 is classified as a stellar host with an effective photospheric temperature of 5,513 K, a radius of 0.9598 R☉, a mass of 0.9406 M☉, an estimated bolometric luminosity of 0.763 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.6 Gyr and a metallicity of [Fe/H] = 0.107 dex (metal-rich relative to the Sun). From Earth, HD 63935 shines at apparent V-band magnitude 8.58 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 63935 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 63935 b sharing its stellar neighborhood alongside HD 63935 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 | HD 63935 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,513 K |
| Stellar Radius | 0.9598 R☉ |
| Stellar Mass | 0.9406 M☉ |
| Bolometric Luminosity | 0.763 L☉ |
| Metallicity [Fe/H] | 0.107 dex |
| Stellar Age | 6.600 Gyr |
| Apparent Magnitude | V: 8.580 · G: 8.394 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.083000 AU |
| Orbital Period | 9.059 days |
| Mean Orbital Velocity | 99.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.4900° |
| Mean Bulk Density | 2.34 g/cm³ (21.2 km/s vesc) |
| Insolation Flux | 115.6000 S⊕ (~157,332 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 159.700 LY (48.974 pc) |