A new type of star: Researchers find 'ancient smokers' in the Milky Way

As of 5:22 p.m| Reading time: 3 minutes

OLD: A new type of star in the middle of the Milky Way

While searching for very young stars, an international research team unexpectedly found a new type of very old star in the central region of the Milky Way. They emit thick clouds of dust, which is why astronomers call them ancient smokers.

Scientists reported in the magazine that the emitted dust could play an important role in the formation of new stars and planets in some regions of the galaxy.Monthly Notices of the Royal Astronomical Society“We were actually looking for something completely different

“Our actual goal was to discover so-called protostars, which exhibit huge bursts of brightness that last for months or even many years,” says Zhen Guo of Valparaiso University in Chile. “These explosions occur in the rotating disk of gas and dust around newly born stars, and can complicate the process of planet formation.”

Until now, astronomers do not know the cause of the explosions. That's why Gu and his colleagues wanted to record as many of these outbreaks as possible and track them as they progressed.

In their research, the researchers used data from an observation project running since 2010 at the European Southern Observatory's VESTA telescope in Chile, which measures the brightness of about a billion stars in the central thickness of the Milky Way.

Vista observes in the infrared and is therefore particularly suitable for detecting newly born stars. These elements are often hidden behind clouds of dust and therefore invisible to optical telescopes, but infrared radiation can penetrate the dust.

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The team was successful: Gu and his colleagues identified 32 protostars that contained flares that increased in brightness by up to three hundred times. Many of these eruptions are still ongoing, allowing researchers for the first time to follow the mysterious phenomena throughout their path.

But in addition to what they were already looking for, the team also discovered something completely unexpected in the Vista data: ancient red stars at the heart of the Milky Way that had changed their brightness in mysterious ways over the years. The researchers identified a total of 21 of these celestial bodies.

They initially had no explanation for the fact that these stars were barely visible at first, but then became much brighter. Finally, additional observations of seven of these objects provided an explanation: the stars apparently ejected huge clouds of dense dust that dulled their brightness.

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These “ancient smokers,” as astronomers call the new type of star, are located in a disc-shaped structure at the center of the Milky Way. Astronomers write that the stars in this disk contain a higher percentage of heavy elements than the stars in the Milky Way. This, according to Gu and colleagues, could also be an explanation for this phenomenon. Because if there are more heavy elements, more dust can form in the cold outer layers of stars.

However, why ancient smokers glow quietly for long periods of time and then suddenly emit their dust in large explosions remains a mystery. With the help of more observations of new stars, researchers want to find out what causes dust explosions.

It is possible that dust emitted from ancient stars in the central region of the Milky Way and other galaxies plays an important role in redistributing heavy elements in space. These heavy elements, in turn, affect the formation of new stars and planets, especially rocky planets like our Earth.