HD 25463 b
Astrophysical Synthesis & Habitability Characterization
HD 25463 b is a confirmed sub-neptune exoplanet orbiting the star HD 25463, located approximately 148.8 light-years (45.62 parsecs) from the Solar System. First announced in 2023 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0271% across the stellar disk), this world measures 2.545 Earth radii and has a measured mass of 8.7 Earth masses. Combining its mass and radius yields a mean bulk density of 2.91 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.34 g⊕ (13.14 m/s²), and an escape velocity of 20.7 km/s.
In its orbital architecture around HD 25463, HD 25463 b completes one full revolution every 7.049 Earth days at a semi-major axis of 0.076 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 117.3 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 1198 K (+925°C / +1697°F) and receiving 461.40 S⊕ (~627,965 W/m²), HD 25463 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 25463 is classified as a stellar host with an effective photospheric temperature of 6,353 K, a radius of 1.4182 R☉, a mass of 1.251 M☉, an estimated bolometric luminosity of 2.94 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.3 Gyr and a metallicity of [Fe/H] = -0.018 dex (near-solar heavy-element abundance). From Earth, HD 25463 shines at apparent V-band magnitude 6.911 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 25463 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 25463 b sharing its stellar neighborhood alongside HD 25463 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 25463 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,353 K |
| Stellar Radius | 1.4182 R☉ |
| Stellar Mass | 1.2510 M☉ |
| Bolometric Luminosity | 2.94 L☉ |
| Metallicity [Fe/H] | -0.018 dex |
| Stellar Age | 2.300 Gyr |
| Apparent Magnitude | V: 6.911 · G: 6.776 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.076000 AU |
| Orbital Period | 7.049 days |
| Mean Orbital Velocity | 117.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.91 g/cm³ (20.7 km/s vesc) |
| Insolation Flux | 461.4000 S⊕ (~627,965 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 148.800 LY (45.618 pc) |