Black hole jet and accompanying erupting nova (artist's concept)

This is an artist's concept looking down into the core of the giant elliptical galaxy M87. A supermassive black hole ejects a 3,000-light-year-long jet of plasma, travelling at nearly the speed of light. In the foreground, to the right is a binary star system. The system is far from the black hole, but in the vicinity of the jet. In the system, an ageing, swelled-up, normal star spills hydrogen onto a burned-out white dwarf companion star. As the hydrogen accumulates on the surface of the dwarf, it reaches a tipping point where it explodes like a hydrogen bomb. Novae frequently pop-off throughout the giant galaxy of 1 trillion stars, but those near the jet seem to explode more frequently. So far, it's anybody's guess why black hole jets enhance the rate of nova eruptions.

[Image description: An artist’s concept looks down into the core of the galaxy M87, which is just left of centre and appears as a large blue dot. A bright blue-white, narrow and linear jet of plasma transects the illustration from centre left to upper right. It begins at the source of the jet, the galaxy’s black hole, which is surrounded by a blue spiral of material. At lower right is a red giant star that is far from the black hole and close to the viewer. A bridge of glowing gas links the star to a smaller white dwarf star companion immediately to its left. Engorged with infalling hydrogen from the red giant star, the smaller star exploded in a blue-white flash, which looks like numerous diffraction spikes emitted in all directions. Thousands of stars are in the background.]