Mysterious ‘Old Smoker’ Stars Discovered in the Milky Way: Could Hold Key to Element Distribution in the Universe
Astronomers have made a groundbreaking discovery in the Milky Way galaxy that could revolutionize our understanding of element distribution in the universe. A decade-long survey of the night sky has revealed a new type of star known as an “old smoker.” These aging, giant stars are located near the heart of the Milky Way and have remained hidden until now. They go through periods of inactivity, fading until they are almost invisible before suddenly belching out clouds of smoke and dust. This phenomenon could play a crucial role in distributing elements across the universe.
The observations were carried out using the Visible and Infrared Survey Telescope, situated at the Cerro Paranal Observatory in the Chilean Andes. The team monitored nearly a billion stars in infrared light, which is invisible to the human eye. Infrared light was essential for this study as it can penetrate through the high concentrations of dust in the Milky Way, allowing astronomers to detect otherwise hidden or faint objects.
Initially, the team’s goal was to search for newborn stars, which are difficult to detect in visible light due to dust and gas obscuring their visibility. However, using infrared light, they were able to track 222 stars that experienced noticeable shifts in brightness. Out of these, 32 were identified as newborn stars that increased in brightness by at least 40 times, with some even reaching a staggering 300 times brighter. These eruptions can last for months, years, or even decades, providing astronomers with a unique opportunity to study the evolution of these stars over time.
Dr. Zhen Guo, Fondecyt Postdoc Fellow at the University of Valparaiso in Chile, explained that these outbursts occur in the slowly spinning disk of matter that is forming a new solar system. While they help the newborn star grow, they also make it more challenging for planets to form. The reason behind the instability of these disks is still unknown and requires further investigation.
During their observations, the team made an unexpected discovery. They identified 21 red stars near the galactic center that experienced unusual changes in luminosity. These changes puzzled astronomers, who were unsure whether these stars were protostars starting an eruption, recovering from a dip in brightness caused by dust, or older giant stars throwing off matter in the late stages of their life. To unravel this mystery, the team focused on seven of these stars and compared the new data with previous surveys. They determined that these stellar objects were a new type of red giant stars.
Red giants typically form when stars have depleted their hydrogen supply for nuclear fusion and begin to die. However, the old smoker stars are different. They remain inactive for years or even decades before emitting clouds of smoke in a completely unexpected way. Dante Minniti, a professor at Andrés Bello University in Chile, described how these stars appear dim and red for several years, sometimes becoming completely invisible.
The old smoker stars were primarily found in the innermost nuclear disc of the Milky Way, where heavy elements are more concentrated. Understanding how these stars release elements into space could revolutionize our understanding of element distribution across the universe. The matter ejected from old stars plays a crucial role in the formation of the next generation of stars and planets. Previously, this was thought to occur mainly in a well-studied type of star called a Mira variable. However, the discovery of a new type of star that throws off matter could have wider significance for the spread of heavy elements in the Nuclear Disc and metal-rich regions of other galaxies.
Astronomers are still working to understand the process behind the release of dense smoke by these old smoker stars and what happens afterward. The findings from this study open up new avenues for research and could potentially reshape our understanding of the universe’s composition and evolution. By studying these enigmatic stars, scientists hope to uncover the secrets of element distribution and gain insights into the formation of stars and planets. The discovery of the old smoker stars marks a significant milestone in our exploration of the cosmos and brings us one step closer to unraveling the mysteries of the universe.
