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.