PSR B1257+12 b
Astrophysical Synthesis & Habitability Characterization
PSR B1257+12 b is a confirmed sub-earth exoplanet orbiting the star PSR B1257+12, located approximately 1956.9 light-years (600 parsecs) from the Solar System. First announced in 1994 by Arecibo Observatory using the Pulsar Timing detection technique, this world measures 0.338 Earth radii and has a measured mass of 0.02 Earth masses. Combining its mass and radius yields a mean bulk density of 2.86 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 0.18 g⊕ (1.77 m/s²), and an escape velocity of 2.7 km/s.
In its orbital architecture around PSR B1257+12, PSR B1257+12 b completes one full revolution every 25.262 Earth days at a semi-major axis of 0.19 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 81.8 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.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for PSR B1257+12 b place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star PSR B1257+12 is classified as a stellar host with a mass of 1.4 M☉. Stellar evolution modeling indicates an estimated stellar age of 3 Gyr. The PSR B1257+12 system is a multi-planet architecture hosting 3 confirmed worlds, with PSR B1257+12 b sharing its stellar neighborhood alongside PSR B1257+12 c, PSR B1257+12 d.
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: Arecibo Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | PSR B1257+12 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | — |
| Stellar Radius | — |
| Stellar Mass | 1.4000 M☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 3.000 Gyr |
| Apparent Magnitude | — |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.190000 AU |
| Orbital Period | 25.262 days |
| Mean Orbital Velocity | 81.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 50.0000° |
| Mean Bulk Density | 2.86 g/cm³ (2.7 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1956.900 LY (600.000 pc) |