Further Observations of the Planets Pulsar
A. Wolszczan
The Pennsylvania State University, Department of Astronomy & Astrophysics,
525 Davey Laboratory, University Park, PA
Recent results of timing observations of the planets pulsar, PSR B1257+12, are discussed. The current timing model includes significant contributions from the second and the third-order period derivatives. If these contributions are related to dynamical effects induced by a fourth distant planet, it could be a Saturn--mass object in a ~170 year orbit around the pulsar.