Rare Supernova Sheds Light on its Mysterious Origins

Type Ia supernovae are some of the most rare and dazzling phenomena in the Universe, and yet astronomers were recently lucky enough to catch a glimpse of one in action. And now, their discovery is shedding light on the mysterious origins of such spectacles, according to a new study.

These explosive events are produced when small dense stars called white dwarfs burst with ferocious intensity. At their peak, these supernovae can outshine an entire galaxy. Although thousands of Type Ia supernovae have been found in the last few decades, the process by which they occur has long been debated by scientists.

That is, until a team of Caltech astronomers working on a robotic observing system known as the intermediate Palomar Transient Factory (iPTF) observed a Type Ia supernova, named iPTF14atg, in a nearby galaxy located 300 million light-years away. The data, described in the journal Nature, lends support to one of two popular theories about the origin of white dwarf supernovae.

First off, it is generally believed that when it comes to Type Ia supernovae, the white dwarf that eventually explodes is one of a pair of stars orbiting around a common center of mass. However, it's the interaction between these two stars where scientists tend to disagree.

One theory - referred to as the double-degenerate model - contends that the companion to the exploding white dwarf is also a white dwarf, and when the two objects merge it causes a stellar explosion. (Scroll to read on...)