supernova-breakout
The brilliant flash of an exploding star's shockwave — what astronomers call the hock breakout — is illustrated in an artist concept. NASA/JPL

Astronomers recently discovered a star that came back from the dead and is expected to cause a supernova event. According to their findings, it was formed when two dead stars merged.

Götz Gräfener of the Argelander Institute of Astronomy in Germany’s University of Bonn discovered the rare star with his colleagues while observing the Cassiopeia constellation. They named the star J005311 and published their study in the international scientific journal Nature.

The nature of the star baffled them because even though it shined 40,000 times brighter than the Sun, it lacked hydrogen and helium. The astronomers explained that these two elements are the last sources of fuel that power stars.

Based on their observations, the astronomers noted that J005311 was exhibiting characteristics of a dead star. Since it was still emitting infrared light despite the absence of hydrogen and helium, Gräfener and his team theorized that J005311 may have been reanimated.

After going through simulations, the astronomers concluded that the star was formed due to a double white dwarf merger event. Nobert Langer, the co-author of the study, explained that this event occurs when two white dwarfs form next to each other.

In certain cases, the two white dwarfs would circle each other and generate gravitational waves, which are space-time distortions. Eventually, the creation of these waves would cause the stars to lose their energy and drift closer to one another. The astronomers speculated that the dead stars may have collided and merged, transforming into a reanimated one with enough mass to start burning again.

Gräfener emphasized the importance of their findings due to the vastness of the galaxy.

“Such an event is extremely rare,” he said in a statement to Phys.org. “There are probably not even half a dozen such objects in the Milky Way, and we have discovered one of them.”

The idea of creating a super bright star out of two dead stars may seem like a happy ending for these cosmic bodies. Unfortunately, this isn’t always the case, especially for J005311. According to the astronomers, the new star will eventually burn through its remaining energy reserve. Once this happens, it will collapse due to its own gravity and cause a supernova. The huge explosion is expected to happen within a few thousand years.

supernova
Pictured, a remnant of Kepler's supernova, the famous explosion that was discovered by Johannes Kepler in 1604. The red, green and blue colors show low, intermediate and high energy X-rays observed with NASA's Chandra X-ray Observatory, and the star field is from the Digitized Sky Survey. X-ray: NASA/CXC/NCSU/M.Burkey et al; Infrared: NASA/JPL-Caltech