PSR B1257+12 is a millisecond pulsar, the remnant of a supernova. PSR B1257+12 hosts the first confirmed exoplanets, found in 1992 by pulsar timing, including a companion only about as massive as the Moon. PSR B1257+12 b is a 0.0-Earth-mass planet, with an orbital period of 25.3 days, at 0.190 AU from its star, discovered in 1994 via pulsar timing. PSR B1257+12 c is a 4.3-Earth-mass planet, with an orbital period of 66.5 days, at 0.360 AU from its star, discovered in 1992 via pulsar timing. PSR B1257+12 d is a 3.9-Earth-mass planet, with an orbital period of 98.2 days, at 0.460 AU from its star, discovered in 1992 via pulsar timing.