Guessing someone’s age at a carnival might be a whimsical game, but for astronomers, determining the ages of stars presents a real challenge. Despite the serene appearance of stars like our Sun once they settle into steady nuclear fusion, understanding their ages remains elusive. However, advancements in technology, such as NASA’s upcoming Nancy Grace Roman Space Telescope, are poised to revolutionize our understanding of stellar populations in the Milky Way galaxy.
Stars are born spinning rapidly, but over billions of years, stars similar in mass to our Sun gradually slow down due to interactions between their magnetic fields and stellar winds. This phenomenon, known as magnetic braking, provides a crucial clue to a star’s age. By measuring the rotation periods of hundreds of thousands of stars, astronomers can estimate their ages and delve into the formation and evolution of our galaxy.
One innovative approach involves analyzing changes in a star’s brightness caused by starspots, akin to sunspots on our Sun. Using artificial intelligence, particularly convolutional neural networks, astronomers can extract rotation periods from these observations. This method, pioneered by a team at the University of Florida, holds promise for accurately measuring stellar rotation periods even with data from telescopes like NASA’s TESS.
The Nancy Grace Roman Space Telescope, set to launch by May 2027, will play a pivotal role in this quest for stellar ages. Through its Galactic Bulge Time Domain Survey, the telescope will observe hundreds of millions of stars in the crowded region near the center of our galaxy. These observations will not only aid in understanding stellar rotation rates but also facilitate diverse scientific investigations, from detecting exoplanets to unraveling the mysteries of star formation.
As the astronomical community continues to refine survey strategies for the Roman Space Telescope, studies like the one funded by NASA on stellar rotation will provide valuable insights. By leveraging cutting-edge technology and collaboration across institutions, astronomers are poised to unlock the secrets of the cosmos, one star at a time.