Astronomers possibly discovered the Milky Way’s first case of a peculiar stellar explosion. The discovery was made with help from NASA’s Chandra X-ray Observatory. It adds to the knowledge of how individual stars shatter and infuse the surrounding universe with elements vital to support life on Earth.
The unique object, found near the middle of the galaxy, is a supernova remnant known as Sagittarius A East, or Sgr A East for short.
According to Chandra data, astronomers formerly labeled the object as what was left of a massive star that blew up in a supernova, one of the multiple variations of exploded stars that scientists have identified.
Chandra’s observations helped a team of astronomers conclude that the object results from a different version of a supernova. It is the explosion of a white dwarf, a fuel-depleted star similar to Earth’s Sun. When a small dwarf draws too much material from a nearby star or merges with a similar white dwarf, it gets destroyed in a show of flashes of light.
Astronomers use the “Type la supernovae” as most of them emit approximately the same quantity of light at all times, regardless of their location. That helps scientists use them to precisely determine distances across space and analyze the universe’s expansion.
Chandra data suggested that Sgr A East isn’t the result of an ordinary Type la. Instead, it looks like it belongs to a particular sort of supernovae that result in various amounts of elements that regular Type las do and less violent explosions.
The subset is called “Type lax,” a likely important supernova family individual.
Ping Zhou of the Nanjing University in China, who conducted the new study at the University of Amsterdam, said:
“While we’ve found Type Iax supernovae in other galaxies, we haven’t identified evidence for one in the Milky Way until now. […] This discovery is important for getting a handle of the myriad ways white dwarfs explode.”
The explosions of white dwarfs are among the most significant universal sources of elements like nickel, iron, and chromium. The only place that scientists know these elements can be synthesized is inside of the so-called nuclear furnace of exploding stars.
Chi Leung, the co-author, said:
“This result shows us the diversity of types and causes of white dwarf explosions, and the different ways that they make these essential elements. […] If we’re right about the identity of this supernova’s remains, it would be the nearest known example to Earth.”
Astronomers are still trying to figure out the reason why Type lax supernova explosions occur. Still, the leading theory is that they result from thermonuclear reactions that travel a lot slower through the star than those found in Type la supernovae.
The relatively slow speed of the blast results in weaker explosions, and, thus, different quantities of elements resulted from the explosion. Also, it’s believed that a particular part of the white dwarf is left behind.
In other galaxies, scientists recorded Type lax supernovae occurring at a rate of approximately 33% that of Type la supernovae.
There have been reported three confirmed Type la supernova remnants in our galaxy and two possible candidates that are less than 2,000 years old, according to an age when remnants are still significantly bright before fading additionally.
Suppose Sgr A East is younger than 2,000 years, and it is the result of a Type lax supernova. In that case, the study may prove that the Milky Way is in alignment concerning the relative numbers of Type lax supernovae observed in other galaxies.