If you live in the southern hemisphere, the next time you will have the opportunity to go outside and look at the night sky. Most of this heavenly plain is covered by a stellar cluster that is torn by galactic tidal forces, and now flows past us like a gigantic river of more than 4,000 stars.
Although this may be simply apparent, it has just been revealed, disclosed by Gaia, which further contributed to the most accurate 3D map of the galaxy.
What makes this stellar stream fascinating is its proximity to the Earth. It's only 100 parsecs (326 light years), giving you an unprecedented opportunity to look into the dynamics of an impaired cluster.
"The identification of adjacent disc streams is how to look for a needle in a haystack. Astronomers have been looking at and through this new stream for a long time since it covers most of the night sky, but only now it realizes that it is, and it is huge, and shockingly close to the Sun, "says astrophysicist Joao Alves of the University of.
"Finding things close to home is very helpful, it means they are not too weak and not too blurry for further detailed study, as astronomers dream."
Stars usually form in clustered star nurseries, but they usually do not hold on for long ̵
It may be hard to see how Alves said, because we need a lot of information to be able to star the stars with each other. But this is what Gaia provided. Not only did he give the exact places in the 3D space for the stars, he gave us his speed, and excited astronomers used this data to identify stellar streams.
So, when the University of Vienna astronomers noticed a group of moving stars moving together, they looked more closely. They discovered that the group had signed the star cluster that was torn apart and now became a stellar stream
Due to the limitations of Gaia's sensitivity, they could analyze 200 stars in detail, but on the basis of the interactions between the stars, the team extrapolated that the stream should contain at least 4,000 stars.
This stellar river is significant, about 200 parsecs (652 light years) wide and 400 parsecs (1,3505 light years) long. These sizes also help assess his age.
The stream, according to the team, is no different from the open Hyades cluster. About 625 million years ago the Hyadis show signs of a tidal tail; this is in the early stages of the violation.
Thus, the researchers believe that this flow is older than Hyadi. Based on this comparison and the collection of star isochronous data (used to calculate the age of stars), the team set the age of the stream about 1 billion years.
This means that about four full-length orbits completed the Milky Way (the Sun takes about 230 million years to orbit the galactic core), which is enough time to pull it into a weakened form.
"As soon as we investigated this particular group of stars in more detail, we knew that we had found what we were looking for: an everlasting current-like structure that spans hundreds of parsecs by one-third of the entire sky," said astronomer Verena Furncrence, actually rotating outside galactic disk, and much more – but the location of this stream inside the disc can make it a valuable tool.
It may also help to shed light on how galaxies get stars, and to test the Milky Way's gravity field, said the experiment
With the help of According to Gay, they plan to look for more such streams in the night sky, hiding in a prominent place.
The team's research was published in the journal Astronomy and Astrophysics .