Astronomers Using White Dwarf Orbiting Massive Neutron Star to Test General Relativity

Posted on April 26, 2013

White Dwarf orbiting massive neutron star

Astronomers announced today that they have been using ESO's Very Large Telescope to observe what they call "a bizarre stellar pair." The bizarre pairing consists of a white dwarf star orbiting the most massive neutron star ever observed. The heavy neutron star is a pulsar that spins 25 times each second and is orbited every two and a half hours by the white dwarf star. This pulsar is named PSR J0348+0432.

Astronomers say the strange combination enables them to test Einstein's theory of gravity in ways that were previously impossible. The astronomers also say Einstein's theory is holding up so far. The research was presented in a paper "A Massive Pulsar in a Compact Relativistic Orbit," by John Antoniadis et al., in the journal Science.

John Antoniadis, a PhD student at the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn and lead author of the paper, said in a statement, "I was observing the system with ESO’s Very Large Telescope, looking for changes in the light emitted from the white dwarf caused by its motion around the pulsar. A quick on-the-spot analysis made me realise that the pulsar was quite a heavyweight. It is twice the mass of the Sun, making it the most massive neutron star that we know of and also an excellent laboratory for fundamental physics."

Here is an artist's animation of the pulsar and orbiting white dwarf. Take a look:

Image: ESO/L. Calcada