PSR 1257+12 (or PSR B1257+12 or PSR J1300+1240)
is a pulsar and the first star for which an
extra-solar planet was detected, which was accomplished in 1992 through
pulsar timing.
It is a planetary system with at least three planets,
PSR 1257+12 A, B, and C (The system's first exoplanet
name was coined before the convention to designate exoplanets with
lower case letters beginning with b, and the three planets are
now also confusingly known by the
conventional designators, PSR 1257+12 b, c, and d).
The term pulsar planet is used for such planets, i.e.,
orbiting pulsars, often also meaning found through pulsar timing,
virtually the only method by which they are identified.