<p>Astronomers for the first time have detected sound waves emanating from a supermassive black hole, researchers said yesterday. With a frequency of 10 million years, the wave is the deepest "note" ever found in the universe -- a B-flat that is 57 octaves below a piano's middle C.</p>
<p>Researchers said heat generated by the sound wave may explain why gases moving within clusters of galaxies do not cool down to form more stars -- an anomaly that has puzzled astrophysicists for years.</p>