A Zombie Star is a star that is created when a supernova Type 1ax explosion occurs that doesn't obliterate itself thereby re-inventing itself as a zombie star in the wake. The zombie star can become a vampire star by consuming fuel and energy from a nearby star to revive itself. It gets its name from the supernatural creation where the monster has died but comes back alive to feast on the living.
Zombie stars tend to appear in binary star systems. The Zombie star was once the bigger of the two stars but was consumed by the more massive star and shrinks into a white dwarf. The star can come back from the dead even though its a dead white dwarf star. The Zombie Star can suck back hydrogen from its nearby Vampire star therefore becoming a Vampire Star itself. When the Zombie star gets roughly the size of a planet, it can go supernova and destroy the original vampire star. Ref: Zombie Stars
Zombie stars don't just feed off stars, they can in the case WD 1145+017 in the constellation of Virgo feast on the energy and materials of its extrasolar planets that orbit the star. Scientists discovered that there were six objects in orbit, each with a comet like tail which indicated that something was not right with the solar system. The star had noticeably more heavier materials on the dwarf star, those materials should have sunk inside the star. The only possible reason was that the metals were being refreshed in a vampirical like way. Ref: A.B.C.
The picture from N.A.S.A. is of a potential zombie star that is located in another galaxy NGC 1301 in the constellation of Eridanus, the river. The picture was taken from the Hubble space telescope and shows what the area in both 2005/6 and 2013 and how it brightened up over a period of time. The star is located about 110 Million Light Years away. Given the time that light takes to travel, the incident would have taken place millions of years ago, about the time of the dinosaurs. Ref: NASA/ESA
You might think that a Zombie Star might just die once and that'll be the end of it. That is not the case, the star iPTF14hls in the constellation of Ursa Major in the northern hemisphere is a star that has exploded multiple times. The star is located 156 Million parsecs away from our solar system so there's no cause for concern from its explosions.