Artist’s impression of a red giant star spewing clouds of smoke and dust
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Astronomers have discovered a star that appears to be spewing smoke. Dubbed “Old Smokers,” they challenge our ideas about what happens at the end of a big star’s life.
Generally, red giant stars begin to pulsate as they age. It lightens, darkens, and becomes brighter again, all the while shedding its outer layers. These pulsating stars are called Mira variable stars, and their pulsations are thought to be caused by waves of plasma moving within the star, helping to eject material into space.
when philip lucas and his colleagues from the University of Hertfordshire in the UK peered into the center of the galaxy using the Visible and Infrared Astronomical Survey Telescope in Chile and discovered many Mira variable stars, but also many more. I discovered. “These old red giants don’t pulsate – they You just sit there normally and then suddenly it goes dark for six months to a few years,” Lucas says. “This is almost unprecedented.”
Further observations revealed that the stars were emitting huge dust plumes that seemed to be blocking starlight from reaching us. The smoke takes months to years to dissipate, providing an explanation for the long-term dimming. This may be a new way for giant stars to end their lives, but it’s unclear how and why it happens.
Because these stars are massive, they create strong gravitational fields that make it difficult to blow away their material. The fact that it’s not pulsating makes the smoke plume even more difficult to explain. Lucas suggests that it may be related to the high concentration of relatively heavy elements near the galactic center, where most of these older smokers are located. This can make it easier for dust particles to form and drift as smoke. “There’s a good chance it’s not, but it’s the only really odd thing that could be relevant in that area,” he says.
Researchers are now looking for more of these strange stars and have found about 90 so far, Lucas said. Their prevalence suggests that they may be important to the environment at the center of the Milky Way, and even more important in other galaxies containing heavier elements.
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