Scientists Find Remnants of A Dwarf White Supernova—Zombie Star of the Cosmos

Like a headline straight from an episode of Star Trek, scientists at NASA confirm that they recently discovered remnants of a "Zombie star" in the galaxy "NGC 1309", nearly 110 million light-years away. Arising out of a very abnormal situation where an unusually weak supernova reaction obliterated only a portion of the white dwarf star, the researchers published their results yesterday, Aug. 7 in the journal Nature.

The resulting "Zombie star" that survived the blast was identified using NASA's Hubble Space Telescope, and a series of images that archived the years preceding the stellar explosion. From a blue star to a dead white dwarf, the weak supernova event is classified as a Type lax, which account for only about 30 documented supernova events;a particularly rare situation throughout the cosmos.

Although the rare white dwarf "Zombie star", designated "SN 2012Z", is of the rare Type lax supernova classification, researchers hope that the information they gather about this particular event will help expand their understanding of the much more common Type la supernovas that serve an important role in the study of space.

"Astronomers have been searching for decades for the star systems that produce Type Ia supernova explosions," Rutgers University Astronomer Saurabh Jha says. "Type Ia [supernovas] are important because they're used to measure vast cosmic distances and the expansion of the universe. But we have very few constraints on how any white dwarf explodes."

"The similarities between Type Iax's and normal Type Ia's make understanding Type Iax progenitors important, especially because no Type Ia progenitor has been conclusively identified" Jha says. "This discovery shows us one way that you can get a white dwarf explosion."

In sharpening and developing Hubble images, lead author Curtis McCully of Rutgers University was able to identify a peculiar object found within the images where he believes the supernova revealed its abnormality.

Analyzing the color composition, and running countless computer simulations of Type lax progenitor systems, McCully and his colleagues were able to confirm that what they saw was in fact a star that had lost its outer hydrogen envelope and revealing its inner helium core.

"I was very surprised to see anything at the location of the supernova" McCully says."We expected the progenitor system would be too faint to see, like in previous searches for normal Type Ia supernova progenitors; It is exciting when nature surprises us."

No longer active in reactions of fusion and fission, the "Zombie star" is the remnant of the white dwarf that should have been obliterated by the supernova that took place. A strange occurrence that likely was the result of an energy dual between a large blue and white dwarf star pair, SN 2012Z will continue to provide insights into the development of supernovas and the effects of siphoning matter between adjacent solar systems.