Astronomers routinely provide the ages of the stars they study. But the methods of measuring ages aren\u2019t 100% accurate. Measuring the ages of distant stars is a difficult task. <\/p>\n
The Nancy Grace Roman Space Telescope should make some progress.<\/p>\n
<\/p>\n Stars like our Sun settle into their main sequence lives of fusion and change very little for billions of years. It\u2019s like watching middle-aged adults go about their business during their working lives. They get up, drive to work, sit at a desk, then drive home. <\/p>\n But what can change over time is their rotation rate. The Sun now rotates about once a month. When it was first formed, it rotated more rapidly. <\/p>\n But over time, the Sun\u2019s rotation rate, and the rotation rate of stars the same mass or lower than the Sun\u2019s, will slow down. The slowdown is caused by interactions between the star\u2019s magnetic fields and the stellar wind, the stream of high-energy protons and electrons emitted by stars. Over time, these interactions reduce a star\u2019s angular momentum, and its rotation slows. The phenomenon is called \u201cmagnetic braking,\u201d and it depends on the strength of a star\u2019s magnetic fields. <\/p>\n The more rapidly a star initially spins, the stronger its magnetic fields. That means they slow down faster. After about one billion years of life, stars of the same age and mass will spin at the same rate. Once astronomers know a star\u2019s mass and rotation rate, they can estimate its age. Knowing stars\u2019 ages is critical in research. It makes everything astronomers do more accurate, including piecing together the Milky Way\u2019s history. <\/p>\n The problem is that measuring rotation rates is challenging. One method is to observe spots on stars\u2019 surfaces and watch as they come into and out of view. All stars have star spots, though their characteristics vary quite a bit. In fact, stars can have dozens of spots, and the spots change locations. Therein lies the difficulty. It\u2019s extremely difficult to figure out the periodicity when dozens of spots change locations on the star\u2019s surface. <\/p>\n This is where the Nancy Grace Roman Space Telescope (the Roman) comes in. It\u2019s scheduled for launch in May 2027 to begin its five-year mission. It\u2019s a wide-field infrared survey telescope with multiple science objectives. One of its main programs is the Galactic Bulge Time Domain Survey. That effort will gather detailed information on hundreds of millions of stars in the Milky Way\u2019s galactic bulge. <\/p>\n The Roman will generate an enormous amount of data. Much of it will be measurements of how the brightness of hundreds of thousands of stars changes. But untangling those measurements and figuring out what those changes in brightness mean for stellar rotation requires help from AI.<\/p>\n Astronomers at the University of Florida are developing AI to extract stellar rotation periods from all that data.<\/p>\n Zachary Claytor is a postdoc at the University of Florida and the AI project\u2019s science principal investigator. Their AI is called a convolutional neural network. This type of AI is well-suited to analyzing images and is used in image classification and medical image analysis, among other things. <\/p>\n \n![\"This](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2024\/04\/Roman-simulate-MW-core.jpg\")