deep bass note from deep black hole

Astronomers reported last week that black holes can sing bass — in a manner of speaking. Using NASA’s Chandra X-ray Observatory, they have detected the deepest note in the universe, a B-flat being emitted by a massive black hole in the Perseus galaxy cluster, 250 million light-years away. Though the researchers could identify it, they couldn’t hear it: The note is 57 octaves below middle-C, at a frequency more than a million billion times deeper than the limits of human hearing. Using observations from Chandra, the astronomers found ripples in the gas filling the galaxy cluster. It is the ripples that are evidence for the sound waves that have traveled from the black hole in the cluster’s center. The study’s team leader, Andrew Fabian of the Institute of Astronomy in Cambridge, England, stated in a press release: “We have observed the prodigious amounts of light and heat created by a black hole; now we have detected the sound.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 9/16/2003.