A cosmic formation path of the Milky Way galaxy has been formulated by scientists. The chart was prepared by a new method to amalgamate information gathered from the ongoing Sloan Digital Sky Survey and an innovative technique to calculate the age of stars. The oldest-ever star and the youngest-ever galaxy have both been discovered by astronomers. The two discoveries can be instrumental in providing an insight into how everything originated.

The studies confirmed the speculations that the central disk of the galaxy grew outwards. The red giant stars are aged approximately 13 billion years and are gathered in the center, while the younger stars that are approximately 1 billion years old are near the periphery of the disk. The information was revealed by astronomer Melissa Ness of the Max Planck Institute for Astronomy in Heidelberg in Germany.

“What we’re able to do is understand how our galaxy has formed in detail, looking at the dispersion of ages, the gradient of the ages, how the ages change as a function of both the height from the (disk’s) plane and the radius”, said Ness.

The survey involves the use of age-dating technique that works on the basis of the size of the star. Star’s chemistry was assessed from the high-quality Sloan survey spectra that was used by the team in combination with the optical data gathered from NASA’s Kepler space telescope. The combination resulted in the creation of a model, which will determine the age of the star.

The astronomers were able to find the correlation between the age and carbon-to-nitrogen of the star where the latter can be determined by analyzing a star’s spectra. Older the star, higher will be the carbon-to-nitrogen ratio. The change in the ratio of 2,000 stars depending upon their mass was calculated. The outcome was inserted in a computer model that computed the masses and ages of 70,000 red giant stars observed in Sloan’s APOGEE survey.