Astronomers have discovered a new type of star nicknamed “Smoking Gun” in the center of the Milky Way. (University of Hertfordshire)
Text/Reporter Chen Juncun
Astronomers recently announced the discovery of a huge new type of old star hidden in the center of the Milky Way. The never-before-seen ancient red giant stars are nicknamed “old smokers” because of the plumes of smoke they emit.
The University of Hertfordshire in the UK stated in a press release that an international research team led by Philip Lucas, professor of astrophysics at the school, discovered that such stars exist in the center of the Milky Way and they can be quiet. It stays there for decades, gradually dimming to the point where it is almost invisible, and then suddenly puffs out clouds of smoke.
Lucas told AFP that scientists had never seen this strange behavior in a red giant star before. “What’s surprising about this new discovery is that we see stars sitting there, doing nothing.”
Then, these stars suddenly dim by 40 to 100 times, sometimes so dim that telescopes can hardly detect them using infrared light. But after a few years, they return to their previous brightness without warning.
Lucas said that based on the known data, this is a situation where the star is emitting smoke, but the cause is unknown. The smoke emitted by these stars temporarily obscures them, making them difficult to see.
During a 10-year study, researchers from the United Kingdom, Chile, South Korea, Brazil, Germany and Italy used the Visible and Infrared Survey Telescope for Astronomy in Chile to observe approximately one billion stars. The result was this groundbreaking discovery.
They also discovered 32 very rare, newly born stars called protostars. They undergo Big Bangs over the course of months, years, or decades as part of the formation of new star systems.
These are newborn stars called protostars. (University of Hertfordshire)
Most of the newly discovered stars are hidden in the vast amounts of dust and gas in the Milky Way and cannot be observed with visible light, but infrared light can penetrate them, allowing scientists to find them for the first time.
Lucas said that among the many stars they observed, about 2/3 were easy to classify, and the rest were more difficult to classify, so they used the Very Large Telescope of the European Southern Observatory to obtain Individual spectra of the remaining stars.
Spectra allow researchers to know how much light they can see at different wavelengths, allowing them to better determine what objects they are seeing.
Researchers say the discovery could change humanity’s understanding of how elements are distributed in space. “Material ejected from ancient stars plays a key role in the life cycles of elements and helps form the next generation of stars and planets,” Lucas explained.
In the study, researchers found at least 21 so-called “smoking stars” whose brightness elusively changed over the 10-year study period. Researchers compared the spectra of seven of the stars with previous data and concluded that they were new types of red giants.
The research results have been published in the British “Monthly Notices of the Royal Astronomical Society”. ◇
