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Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Astronomers have uncovered a previously unseen "river of stars" past the Earth

Astronomers have uncovered a previously unseen "river of stars" past the Earth



If you live in the southern hemisphere, the next time you get the chance, go out and look at the night sky. Most of this celestial plane is covered with star clusters that are torn apart by galactic tidal forces and now run alongside us like a giant river of over 4000 stars.

Although it may be prominent, it is only open, revealed by Gaia's data, which further facilitates the most accurate 3D map of the galaxy.

What makes this stellar stream exciting is its proximity to the Earth. It is only 100 parse (326 light years), offering an unprecedented opportunity to look at the dynamics of the torn cluster.

"Identifying the nearby streams of discs is like searching for the proverbial needle in a haystack, and in this new stream for a long time since it covers most of the night sky but is only now aware that it is there, and is huge and shocking near the Sun, "says astrophysicist João Alves of the University of California,

" Finding things close to home is very useful, it means they are not too weak or too blurry for further details study, as astronomers dream. " Usually they do not last long ̵

1; maybe a few hundred thousand years. There is a lot of mass needed to build enough gravity to hold a bunch together – even the small galaxies that surround the Milky Way can be torn apart by its tidal forces and end up stretching in long rivers of stars circling around the galactic core. They can be difficult to look at, as Alves says, because we need a lot of information so we can connect the stars to each other. But that is what Gaia has provided. Not only has he assigned exact locations in the 3D space for stars, he has given us his speeds, but the excited astronomers have used this data to identify stellar streams.

So when the astronomers at the University of Vienna noticed a group of stars moving together, they looked closer. They found that the group had the signatures of a star cluster that had been torn, and now it's a star-like stream.

 southern river The river of stars in the southern sky. (Gaia DR2 skymap)

Due to Gaia's sensitivity limitations, they were able to analyze only 200 stars in detail, but based on interactions between the stars, the team extrapolated that the stream should contain at least 4,000 stars

This star river is tangible, about 200 parse (652 light years) wide and 400 parse (1,305 light years) long. These dimensions also help to estimate his age.

The flow, the teams say, does not differ from the open clandestine of the Hyades. About 625 million years ago, the Hyades show evidence of a tidal tail; this is in the early stages of disruption.

Therefore, the researchers believe that this stream is older than the Hyades. Based on this comparison and dataset of star isochrons (used to calculate the age of the stars), the team set the age of flow to about 1 billion years.

This means that it is completed around four full orbits of the Milky Way (the Sun takes about 230 million years to travel around the galactic core), which is enough time to stretch into its attenuated form. "As soon as we explored this particular group of stars in more detail, I knew we had found what we were looking for: a centuries-old structure that stretches for hundreds of parsees in a third of the whole sky," said astronomer Verena Furankranz actually go beyond the galactic disk and are much larger – but the location of this stream inside the disk can make it a valuable tool, for example, it can be used to curb the mass distribution of the Milky Way. shed holy on the way galaxies get stars and test the gravitational field of the Milky Way, researchers have said.

With the help of the Gaia Data, they plan to seek more such streams in the night sky, hiding in a clear view

is published in the journal Astronomy and Astrophysics


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