Zombie Star! Astronomers discover a new type of supernova that leaves its 'victim' partially alive!
Meteorologist/Science Writer
Thursday, October 30, 2014, 4:07 PM - Yes, you read that headline correctly. There are stars out there in the universe that die, tear off parts of their living companion star to feed themselves, then erupt into spectacular explosions, but ... rather than being completely destroyed, they're left in a kind of 'undead' state in the end.
Hank Green, from SciShow Space, describes this whole process in the video above.
Although the most common thing that pops into mind when someone mentions a supernova is very likely the explosion that occurs when an incredibly massive star reaches the point where it's so old that it has fused iron in its core. At that point, no star is big enough to fuse iron together into anything else, the fusion process stops and the immense weight of the star causes it to collapse in upon itself. However, there's more than one type of supernova. The core collapse of a massive star (as was just described) actually covers more than one type of supernova, as there are subtle but important differences between them.
The process that creates a zombie star is a Type 1a supernova, which is shown in pictorial form below.
Credit: NASA/ESA/A. Feild
Now, that's what normally happens, though. When it comes to a zombie star, something different happens in the second-last and last panel of the sequence. Astronomers and astrophysicists are still working on the why, but somehow, rather than the white dwarf star being completely obliterated by the supernova explosion it sets off during the above process, some part of the star remains behind to live on.
Quite frankly, even the basic description of how a white dwarf - which is the dead remnant of a Sun-like or similar star - tears matter from its companion star to feed itself is enough to evoke the idea of a zombie, but the fact that this type of star then survives the supernova explosion that should destroy it ... now that's just weird.
I guess the supernova wasn't a head-shot.
H/T to Hank Green & SciShow
(Teaser image credit: ESO/M Kornmesser)
