A couple of stars in the planetary nebula Henize 2-428 are close, and getting closer. The two white dwarfs are circling each other every 4 hours or so at a pretty high rate of speed for such massive objects. The rotation and its speed mean that the orbit decays and they gradually draw near each other.
When that happens, the two will fuse and form a single star just under twice the size of the sun -- for a little while, anyway. Then they'll blow up in a Type Ia supernova and could be brighter than most of the other stars in the sky.
But although this is almost ready to happen in cosmic terms, there's no need to get the sunscreen ready for any outside nighttime activity. According to the measurements made by astronomers, the collision and explosion will happen sometime in 700,002,015 A.D.
Give or take.