The relics of the old galactic core, when our galaxy was still young, are a scattering of stars dispersed across the Milky Way’s center. Astronomers now have proof of that, and it is genuinely incredible!
A team of astronomers had discovered 18,000 stars from the ancient days of the Milky Way when it was just a compact cluster of proto-galaxies coming together to dream of greater things. This work was tremendously challenging, but the astronomers did that using measurement from the most precise three-dimensional map of the galaxy ever created.
Discover the fascinating story below.
Milky Way and Its Ancient ‘Heart’ Unveiled For the First Time
[…] our results significantly flesh out the existing picture by showing that there is indeed a tightly bound in situ ‘iceberg,’ whose tips have been recognized before, explained the team of researchers led by the incredible astronomer Hans-Walter Rix of the Max Planck Institute for Astronomy.
The Milky Way’s 13 billion years of history are a challenging jigsaw that must be pieced together from the galaxy’s current condition. Luckily, our team of astronomers here was brave enough to learn more about that!
How did they do it?
For years, the Gaia satellite observatory has been monitoring the stars and recording measurements of their three-dimensional locations and movements within the galaxy while orbiting Earth around the Sun. What’s best is that Gaia also collects data that enables estimations of the metallicity of the stars.
So, the team examined red giant stars a few thousand light-years from the Milky Way via all the Gaia data. Doing that was successful enough because they located 2 million stars, and a neural network that could identify metallicities examined their light.
Finally, the astronomers discovered a population of stars with comparable ages, orbits, and abundances, indicating that they existed prior to the Milky Way being entirely populated with stars and expanding due to collisions with other galaxies, which began around 11 billion years ago.
Because they are extremely ancient, metal-poor, and located in the galaxy’s center, Rix has dubbed them, in a funny way, the “poor old heart” of the Milky Way. According to the team, the population consists of the remains of proto-galaxies. Quite impressive, isn’t it?!
The wretched old heart stars are the offspring of the proto-galaxy stars’ demise, not of their birth in these proto-galaxies. More curious is that they are more than 12.5 billion years old, according to the team.
Now, astronomers need to continue their investigations to unveil even more details!