“The surviving star is a bit like Obi-Wan Kenobi from ‘Star Wars’ returning as a force ghost,” Andy Howell, a professor at the University of California, Santa Barbara, said in a statement. Pour the star, but it came back stronger than we thought. It’s still the same star, but in a different form. It’s beyond death.”
Howell is a co-author of a paper published in the Astrophysical Journal that documents the star not only survived but also brighter than before.
“No one expected to see a surviving star get brighter. That’s a real puzzle,” said Curtis McCully, lead author of the study. He is a postdoctoral fellow at the University of California, Santa Barbara and the Las Cumbres Observatory.
There are indications that SN 2012Z was an unusual supernova explosion. It’s dimmer and slower, and some astronomers think the supernova could be related to a failed supernova that could leave a black hole behind.
In this case, it appears that the star has undergone a half-explosion, becoming swollen and bright in the process. But the explosion wasn’t strong enough to tear apart the star and blow all its material into deep space and to form the brilliant nebula often left behind by supernovae.
Supernovae are not a particularly well understood phenomenon. The researchers hope that bizarre outliers like this zombie star may help change that. “Now we need to understand what makes a supernova fail,” McCully said.
