19 April 2001CfA Colloquium


Title: Neutron Star Planets for Fun and Profit

Speaker: Aleksander Wolszczan

Abstract: The three terrestrial-mass planets in orbit around a billion-year old neutron star, PSR B1257+12, have been discovered in 1992. It was a superb precision of the pulse timing technique that has made this detection possible. A subsequent measurement of perturbations between the two larger planets was first used to confirm the planets and then to determine true masses and orbital inclinations of these objects. Most recently, a fourth, very low-mass body in a 4-year, highly eccentric orbit around the pulsar has been discovered. A possibility that the innermost planet is an artifact of radio signal propagation in the solar wind has been verified and dismissed. A giant planet-mass body has been found to orbit a binary pulsar, PSR B1620-26, in the M4 globular cluster. A long standing possibility of two planets around a "normal" pulsar, PSR B1257+54, has not been confirmed.

We will describe these and other developments in the pulsar planet research, outline the current understanding of planet formation around neutron stars and discuss a relationship of this process to planets around Sun-like stars.

Reference for students:

Lunch with the students will be on Friday, April 20th at 12:00 in the classroom.