Astrophysicists have found the best evidence yet for a low-frequency “hum” of gravitational waves rippling through the cosmos, based on 15 years’ worth of ultra-precise measurements checking the timing of radio pulses from distant stars.
The evidence, newly published in the Astrophysical Journal Letters, comes from several teams of researchers working in the U.S. and Canada as well as Europe, India, Australia and China.
The teams monitored radio emissions from a total of 115 ultra-dense, spinning stars known as pulsars. Nearly 70 of those pulsars were observed by the North American Nanohertz Observatory for Gravitational Waves, known as NANOGrav.
“This is key evidence for gravitational waves at very low frequencies,” Vanderbilt University’s Stephen Taylor, who co-led the search and is the current chair of the NANOGrav Collaboration, said today in a news release. “After years of work, NANOGrav is opening an entirely new window on the gravitational-wave universe.”