G. Stinson / MPIA
Artistic rendering of the Milky Way, based on the ages of 80,000 stars: the oldest stars appear in red and the younger ones in blueG. Stinson / MPIABased on information from 80,000 stars, an international group of astronomers has created the largest “growth chart” of the Milky Way. The chart confirms that over the past ten billion years the galaxy that houses the solar system has grown outward from its center. Presented on January 8, 2016, at a meeting of the American Astronomical Society (AAS), the chart is the work of a team led by Melissa Ness and Marie Martig, both of the Max Planck Institute of Astronomy in Heidelberg, Germany. The researchers calculated the ages of 80,000 stars located at distances of up to 65,000 light-years away from the galactic center. The chart helps visualize the history of the galaxy’s formation. Stars more than ten billion years old, which appeared when the galaxy was young and much smaller, are concentrated at the center of the Milky Way. Far from the center lie the younger stars, born in the past three billion years, when the galaxy had practically reached its current size and acquired a spiral shape, its curved arms stretching out from its center. To calculate the age of the stars precisely, the astronomers combined observations made using NASA’s Kepler space telescope with observations of the same stars from the APOGEE survey, part of the broader Sloan Digital Sky Survey (SDSS).
Republish