Philip Lucas/University of Hertfordshire
The artist’s illustration depicts an old smoking star, or aging red giant star, emitting thick clouds of smoke and dust.
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A decade-long study of the night sky has revealed a mysterious new type of star that astronomers call an “old smoker.”
These previously hidden stars are aging and the giant stars are closer to Earth. center of the milky way galaxy. The star has been inactive for decades, dimming until it is almost invisible, then spewing out clouds of smoke and dust. Astronomers believe that stars may play a role in distributing elements throughout the universe.
4 studies Details of the observations published in the Monthly Notices of the Royal Astronomical Society on January 25th.
Astronomers observed the old smoker star for the first time in a survey that monitors about 1 billion stars in infrared light, which is invisible to the human eye.
The observations were made with a visible and infrared surveying telescope located at the Cerro Paranal Observatory, a vantage point high in the Chilean Andes.
The research team’s initial goal was to search for newborn stars. The stars are difficult to detect in visible light because they are covered in dust and gas from the Milky Way. However, infrared light can penetrate galaxies’ high concentrations of dust and reveal hidden or faint objects.
Philip Lucas, a professor of astrophysics at the University of Hertfordshire, said two-thirds of the stars were easy to classify, but the rest were more difficult, so the team used the European Southern Observatory’s Super Large He said he used a telescope to study individual stars.Lucas was the lead author one study I am a co-author of the other three books.
Philip Lucas/University of Hertfordshire
This diagram shows an eruption occurring in a swirling disk of material around a newborn star.
Astronomers monitored hundreds of millions of stars and tracked 222 that experienced significant changes in brightness. The researchers determined that 32 of them were newborn stars whose brightness increased by at least 40 times, and some by as much as 300 times. Most of the eruptions are ongoing, allowing astronomers to continue monitoring how the star evolves over time.
“Our main goal was to find rarely seen newborn stars, also called protostars, while they are experiencing massive explosions that last for months, years, or even decades.” said Dr. Zhen Guo, a postdoctoral researcher at Von Desight University. This was announced by Chilean club Valparaiso in a statement.Mr. Guo main author two the studyand the other two books are co-authors.
Philip Lucas/University of Hertfordshire
Astronomers used infrared telescopes to spy on the star, which has gradually become 40 times brighter over two years and has remained bright since 2015.
“These explosions occur within the slowly rotating disk of material that is forming the new solar system. They help the newborn star in the center grow, but make planet formation difficult. “We still don’t know why the disk becomes unstable like this,” Guo said.
While observing stars near the center of the galaxy, the research team identified 21 red stars that experienced unusual brightness changes that puzzled astronomers.
“Whether these stars are protostars that have started erupting, are recovering from a dip in brightness caused by a disk or dust shell in front of the star, or are older stars that are ejecting material in their later stages. We didn’t know if it was a giant star in their life,” Lucas said.
The researchers focused on seven of the stars and compared the new data they collected with data from previous surveys, determining that the stars were a new type of red giant.
Philip Lucas/University of Hertfordshire
Infrared images show a red giant star near the center of the Milky Way, 30,000 light-years away. The star disappeared and reappeared several years later.
Red giant stars form when a star exhausts its supply of hydrogen for nuclear fusion and begins to die. In about 5 or 6 billion years, our sun will likely become a red giant star, swelling and expanding as it sheds layers of material and vaporizing the inner planets of our solar system, but the fate of Earth remains unknown. It is said that it is. NASA.
However, the stars discovered during the survey are different.
“These old stars sit quietly for years or decades, and then, completely unexpectedly, they let out smoke,” said Dr. Study co-author Dante Miniti said: statement. “For several years, it can appear so dark and red that you can’t see it at all.”
Stars are primarily found in the Milky Way’s innermost core disk, where they have higher concentrations of heavy elements. Understanding how old smokers release elements into space could change the way astronomers think about how such elements are distributed throughout the universe.
Astronomers are still trying to understand the processes behind stars emitting dense smoke and what happens next.
“Material ejected from old stars plays an important role in the life cycle of elements and helps form the next generation of stars and planets,” Lucas said. “This was thought to occur mainly in a well-studied type of star called a Mira variable star. But the discovery of a new type of star that throws off material is a new type of star that can be found in metal-rich nuclear disks or in other galaxies. This may have broader implications for the diffusion of heavy elements in this region.”