An unusual binary star produces the fastest nova ever recorded

The sudden bursts of light caused by the release of energy by the white dwarfs that make up a binary star system together with a companion star are called “novae”. A study published this Wednesday (15) in Research Notes from the American Astronomical Societyreports what astronomers call the fastest nova ever observed.

According to the website Phys, the unusual event drew scientists’ attention to an even more unusual star. As they study it, they may find answers not only to the nova’s many anomalous traits, but also to broader questions about the chemistry of our solar system, the death of stars, and the evolution of the universe.

Each nova is created by a white dwarf – the very dense core of a star’s leftovers – and a nearby companion star. Over time, the white dwarf absorbs matter from its neighbor and heats that material, causing an uncontrolled reaction that releases an explosion of energy at the speed of light. This process usually takes one to two weeks, normally.

However, on June 12, 2021, the nova named V1674 Hercules erupted so brightly that it was visible to the naked eye. In just over 24 hours, that glow disappeared completely, making this the fastest nova in the history of astronomical observations.

“The previous fastest nova was the one we studied in 1991, the V838 Hercules, which declined in about two to three days,” said Sumner Starrfield, an astrophysicist at the University of Minnesota’s School of Earth and Space Exploration (ASU. ), principal. .

In addition to being the fastest of all, the new V1674 Hercules has an unusual feature. According to the researchers, its light and the energy it gives off pulsate like the sound of a reverberating bell. Every 501 seconds, there is an oscillation that observers can see in both visible light waves and X-rays.

And more than a year after its explosion, the nova still shows this oscillation, which, according to scientists, has been going on even longer. “The most unusual thing is that this wobble was seen before the explosion, but it was also evident when the nova was about 10 magnitude brighter,” says co-author Mark Wagner of Ohio State University, who is also the head of science. of the Observatory. of the Large Binocular Telescope used to observe the nova.

Another strange thing was noticed as the astronomers monitored the matter ejected by the new explosion. A kind of wind, which may depend on the positions of the white dwarf and its companion star, is shaping the flow of material in space around the system.

While white dwarfs collect and alter matter from their companion stars, novae temper the surrounding space with new material during their explosions. This is an important part of the matter cycle in space, as what is ejected in these processes eventually forms new star systems.

For scientists, such events also helped shape our solar system, which means that studying these phenomena can provide answers to the composition of the Earth.

“We are always trying to understand how the solar system formed and where its chemical elements come from,” says Starrfield. “One of the things we will learn from this nova is, for example, how much lithium was produced by this explosion. We are now pretty sure that a significant fraction of the lithium we have on Earth was produced by these types of explosions. “

Additionally, explosions such as V1674 Hercules can tell more about how stars in binary systems evolve towards death, a process that is not yet well understood. They also act as living laboratories where scientists can see nuclear physics in action and test theoretical concepts.

The post Unusual Binary Star Produces Fastest Nova Ever Recorded first appeared on Digital Look.

Source: Olhar Digital