The first growth map of the Milky Way has been revealed thanks to the collaborative efforts of scientists working under the Sloan Digital Sky Survey project umbrella.
The growth map of our galaxy is no meager feat for science. It is only due to recent technological developments and methodological approaches that this breakthrough was possible. Data collected under the Sloan Digital Sky Survey and the sub-project Apache Point Observatory Galaxy Evolution Experiment (APOGEE) have been crucial in the creation of Milky Way’s growth map.
The growth map takes into consideration the age of the stars, their growth and the subsequent growth of the spiral galaxy. Encompassing age data of 70,000 stars galaxy wide, the Milky Way growth map shows stars as far away as 50,000 light years from our solar system.
The first growth map of the Milky Way has been revealed and thoroughly explained during the American Astronomical Society meeting taking place in Kissimmee, Florida.
Milky Way’s growth map reveals how the galaxy has evolved and grew from the inside to outside. The spiral galaxy’s central disk was the first to form. Red giant stars located here have been dated to be 13 billion years old. Red giant stars are clustered to the center of the galaxy’s central disk. The outskirts or the disk’s edge is populated by younger stars date to be about 1 billion years old.
According to Melissa Ness working with the Max Planck Institute for Astronomy (Germany), plotting the stars’ ages helped create Milky Way’s growth map. When Milky Way was a young, just forming galaxy, there were only the now red giant stars at the center of the galaxy’s central disk. The spiral galaxy which is home to our solar system ‘grew up by growing out’ according to Melissa Ness.
The 70,000 stars encompassed in the Milky Way growth map were dated based on information obtained from studying approximately 2,000 red giant stars. The mass of these stars in addition to data retrieved from the Sloan survey spectra enabled the scientific team to develop an age-dating technique. The Kepler Space Telescope also helped in providing crucial data.
Previously, obtaining data on a star’s age was a difficult process. Now, using stellar spectra and the carbon-to-nitrogen ration in addition to a star’s mass has given birth to a new age-dating technique according to Marie Martig working with the Sloan Digital Sky Survey.
Photo Credits: i4u