This Hubble Space Telescope image of the core of the spiral galaxy M51 shows a dark “X” silhouetted across the galaxy’s nucleus. The “X” is caused by absorption of light by dust and marks the position of a black hole which may have a mass about one-million times the mass of the Sun. The darkest bar may be an edge-on view of a dust ring 100 light-years in diameter. It blocks the black hole its accretion disk as seen from Earth. The second bar of the “X” could be a second disk seen edge on, or it might be rotating gas and dust in M51 intersecting with the jets and ionization cones from the black hole.

Image Credit: NASA