It was considered for some time that our galaxy of roughly the same shape formed after merging with another, smaller galaxy – Gaia-Enceladus. This was supposed to happen about 10 billion years ago.
According to scientists from several affiliated universities, including Ohio State University and the University of Birmingham, the Milky Way was already containing a large number of stars at the time of galaxies merging. Today most of them are supposed to form the center and circumference of the galaxy, while most of the stars in Gaia-Enceladus lie at the fringes of the Milky Way.
The analyzes regarding the behavior of the different stars are also interesting. According to the research team, Gaia-Enceladus stars behave “differently” from the original stars of the Milky Way. They have different chemical compositions and different orbits.
Scientists have determined the age of the stars with the help of stellar seismology (the science of stellar earthquakes), and it is still a relatively young science.Which deals with the internal structure of the stars. Science studies the oscillations in stars, and the sound waves that pass through their inner spaces. Thanks to new methods and computer simulations, researchers are able to estimate the age of stars more accurately than ever before.
Astronomy was supplemented by spectroscopy, which allows them to determine the chemical composition of the stars; Even this leads to a better determination of the age of the star. The chemical composition of stars changes drastically over time.
The study’s first published results are available in the peer-reviewed journal Natural AstronomyIt is only a preliminary step to much deeper discoveries, which in turn should lead to a more accurate time estimate of how our galaxy has evolved.