The first detection of X-ray emission from the Perseus cluster (astronomical designation Per XR-1) occurred during an Aerobee rocket flight on March 1, 1970.

[5] In 2003, a team of astronomers led by Andrew Fabian at Cambridge University discovered one of the deepest notes ever detected, after 53 hours of Chandra observations.

[6] No human will actually hear the note, because its time period between oscillations is 9.6 million years, which is 57 octaves below the keys in the middle of a piano.

In May 2022, NASA reported the sonification (converting astronomical data associated with pressure waves into sound) of the black hole at the center of the Perseus galaxy cluster.

[7][8] A similar case also happens in the nearby Virgo Cluster, generated by an even larger supermassive black hole in the galaxy Messier 87, also detected by Chandra.