There are numerous theories about how our home galaxy came to be. However, a recent study may finally shed light on the origins of the Milky Way. The GAIA-ESO project recently released the details of a study that provides evidence regarding certain stars with specific chemical compositions that may hold the answers to questions about galactic evolution.
The GAIA-ESO project is one of the landmark projects of the European Southern Observatory. It is primarily a survey project with the aim of mapping out as much of the Milky Way as possible. It also focuses on gathering information about the history of the galaxy from its early beginnings to how it came to be in its present state. The GAIA-ESO project was able to gather and analyze data that indicates previous theories about the chemical composition of numerous stars in our galaxy's disc may be correct. The Milky Way's disc consists of billions of stars and is responsible for giving our galaxy its distinctive saucer like shape.
The project used data collected by one of the biggest terrestrial telescopes on the planet, the 8-m VLT in Chile. The team tracked specific elements like magnesium that are known to be present in stars that formed quickly and died relatively young. The amount of magnesium the inner sections of the Solar Circle, an imaginary circle tracking our sun's orbit around the galaxy, indicate that this region of the galaxy has high concentrations of "metal poor" stars that are older compared to stars that contain a lot of metals. This distribution of older and newer stars supports theories that say that the Milky Way formed "inside-out," which means that many older stars are close to the center of the galaxy while younger stars that were formed later are distributed in the outer part of the galactic disc. The team published its findings in the journal Astronomy and Astrophysics
Very large stars often have very short lifetimes. However, these stars die and explode causing violent supernovae. These supernovae cause the production and distribution of massive amounts of magnesium seeding entire areas with the element. After exploding in a violent death, the remnants of a massive star often form black holes or neutron stars. Moreover, the death throes of massive stars can also sometimes cause the birth of new stars. Scientists working on the GAIA-ESO project were able to map out areas that in the past, were full of massive stars that lived relatively short lives only to give birth to newer magnesium-rich stars. In contrast, the outer regions of the galaxy are packed with stars that have very low levels of magnesium indicating that these areas are a lot younger compared to the inner regions of the Milky Way.
