"There are many theories about what happens to matter under such extreme conditions," John Antoniadis, with the Max Planck Institute for Radio Astronomy in Bonn, Germany, told Discovery News.
Making the measurements required patience and extreme precision, but in the end the gravitational impact predicted by Einstein's theory proved correct. In this case, the loss of energy due to gravity waves from the system escaping into space slowed the pair's orbital period by eight-millionths of a second per year.
"It is essential to know the masses of the pulsar and white dwarf to high accuracy because these are the actual inputs that General Relativity or other theories use to predict the orbital decay," said astronomer Ryan Lynch, with McGill University in Montreal, Canada.
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Astronomers also needed a way to precisely measure the pair's orbital period. The pulsating neutron star served as their clock.
"These things came together to make J0348 a power tool," Lynch wrote in an email to Discovery News.