Evan Pugh Professor of Astronomy & Astrophysics
M.Sc., N. Copernicus University, Torun, Poland, 1969Ph.D., N. Copernicus University, Torun, Poland, 1975
Alex Wolszczan's research interests concentrate on neutron stars, their structure, magnetospheres and, above all, the applications of rotation-powered neutron stars (radio pulsars) as probes of numerous phenomena in physics and astrophysics, such as turbulence in the ionized interstellar medium, dynamics and evolution of globular clusters, relativistic gravity, and extrasolar planetary systems. Among various pulsar discoveries by Wolszczan and his collaborators, a 10-hour binary system of two neutron stars, PSR B1534+12, and a 6.2-ms pulsar, PSR B1257+12, which is orbited by at least three terrestrial mass bodies, deserve particular attention.
PSR B1534+12 represents an excellent probe of gravity under strong field conditions. It is considered to become even more useful in this respect than the famous Hulse-Taylor binary. These two binary systems have been used to study relativistic orbital effects and their utility to test General Relativity and the competing gravity theories in the conditions that cannot be reproduced on the Earth or anywhere in the solar system.
The PSR B1257+12 planets are the first ones ever found beyond the solar system and the first new planets detected since Tombaugh's discovery of Pluto in 1930. Wolszczan has confirmed their existence by an experimental demonstration that the predicted gravitational perturbations between the 1257+12 planets do exist. A confirmed discovery of the first extrasolar planetary system has provided a long awaited breakthrough for planetary search programs, and was followed by a series of detections of giant planets around Sun-like stars by optical astronomers.
Continuing pulsar surveys by Wolszczan and his students and collaborators have led to further discoveries, such as PSR J1713+07, possibly the most accurate pulsar clock and PSR J0538+28, a new pulsar-supernova remnant association. The pulsar backend hardware designed by Wolszczan and constructed at Penn State (the Penn State Pulsar Machines) is expected to help unraveling new types of astrophysical objects, such as ultra-fast rotating neutron stars and neutron star-black hole binaries.
Right: A comparison of orbits and sizes of the inner solar system planets (top) and the three planets detected around PSR B1257+12 (bottom). The sun and the pulsar are not drawn to scale.
