Question about the Black Hole B-Flat

The reports say that the black hole discovered by CHANDRA is emitting
a frequency "57 octaves below middle C". Middle C is usually accepted
to be 256 Hz; 57 octaves below that is around 3.5E-15 Hz - a period of
almost 9 million years (all BOE calculations.)

I'm fascinated to know: how'd they detect and measure this?

Thanks,

- L
--
Larry Huntley Beaverton, Oregon
Skep-Ti-Cult® Member #130-978649-969 http://www.skepticult.org/
"Skepticult subculture -- the dark underbelly of Usenet"
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If you really work at it, you can clutter up many types of music with
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