New type of gravitational waves reveal the breath of the cosmos

Independent observations made by the most powerful radio telescopes around the world including the Sardinia Radio Telescope have discovered new gravitational waves that oscillate very slowly and pervade every corner of the universe with a regular rhythm reminiscent of breathing. Astronomers say the discovery of the ultra long, very low frequency gravitational waves opens a new chapter in astrophysics, allowing phenomena that were previously hard to detect to be studied.

The findings, published in multiple papers in the journals Astronomy and Astrophysics and Astrophysical Journal Letters and on the arXiv platform, are the work of five groups: the European Pulsar Timing Array (Epta), in which Italy participated with the National Institute of Astrophysics, through its Cagliari section, the Sardinia Radio Telescope and the University of Milan Bicocca; the Indian Pulsar Timing Array (InPta) collaboration involving India and Japan; the Nird America with NanoGrav; Australia with Ppta; and China with Cpta.

But the breath of space-time could be captured above all thanks to pulsars, namely extremely dense stars that rotate on themselves and whose rhythm is altered by the passage of new gravitational waves.

Radio telescopes measured these alterations with precision, obtaining a kind of portrait of the dilations and compressions of space-time. Besides the Sardinia RadioTelescope, the European radio telescopes that took part in the discovery are the Effelsberg Radio Telescope in Germany, the Lovell Telescope at the Jodrell Bank Observatory in the United Kingdom, the Nancay Radio Telescope in France and the Westerbork Radio Synthesis Telescope in the Netherlands.