The PSR B1257+12 system contains 3 exoplanets. It is located 1956.94 light years away from the solar system.
| Mass | 1.4 solar masses |
| Radius | 1.2 solar radiae |
| Temperature | - kelvin |
| Stellar Metallicity | - decimal exponent |
| Age | 3 billion years |
With a mass below 5 Earth masses, a density of 2.85, and a semi-major axis of 0.19 astronomical units, PSR B1257+12 b could, potentially, be an ocean world - a planet with no dry land.
| Mass | 0.020 Earth masses |
| Density | 2.850 grams per cubic centimeter |
| Radius | 0.338 Earth radiae |
| Semi-major Axis | 0.19 AU |
| Eccentricity | 0 |
| Orbital Period | 25.262 days |
| Discovery Method | Pulsar Timing |
| Discovery Facility | Arecibo Observatory |
| Discovery Telescope | 305 m Arecibo Radio Telescope |
| Discovery Instrument | Arecibo Radio Reciever |
| Discovery Date | 1994-04 |
| Reference | Wolszczan 1994 |
With a mass below 5 Earth masses, a density of 3.39, and a semi-major axis of 0.36 astronomical units, PSR B1257+12 c could, potentially, be an ocean world - a planet with no dry land.
| Mass | 4.300 Earth masses |
| Density | 3.390 grams per cubic centimeter |
| Radius | 1.910 Earth radiae |
| Semi-major Axis | 0.36 AU |
| Eccentricity | 0.0186 |
| Orbital Period | 66.542 days |
| Discovery Method | Pulsar Timing |
| Discovery Facility | Arecibo Observatory |
| Discovery Telescope | 305 m Arecibo Radio Telescope |
| Discovery Instrument | Arecibo Radio Reciever |
| Discovery Date | 1992-01 |
| Reference | Wolszczan et al. 1992 |
At 3.902 Earth masses, PSR B1257+12 d is a so called Super Earth. Super Earths could be terrestrial worlds like Earth, but they could also be ocean worlds or terrestrial worlds wrapped in a substantial atmosphere, in which case some refer to them as Mini Neptunes.
| Mass | 3.900 Earth masses |
| Density | 3.670 grams per cubic centimeter |
| Radius | 1.800 Earth radiae |
| Semi-major Axis | 0.46 AU |
| Eccentricity | 0.0264 |
| Orbital Period | 98.211 days |
| Discovery Method | Pulsar Timing |
| Discovery Facility | Arecibo Observatory |
| Discovery Telescope | 305 m Arecibo Radio Telescope |
| Discovery Instrument | Arecibo Radio Reciever |
| Discovery Date | 1992-01 |
| Reference | Wolszczan et al. 1992 |