Here's the info from Hubble.com:
"X" Structure at Core of Whirlpool Galaxy (M51)
This image of the core of the nearby spiral galaxy M51, taken
with the Wide Field Planetary camera (in PC mode) on NASA's Hubble Space
Telescope, shows a striking , dark "X" silhouetted across the galaxy's nucleus.
The "X" is due to absorption by dust and marks the exact position of a black
hole which may have a mass equivalent to one-million stars like the
Makes you think, don't it?