Strange things are going on in the Milky Way.
According to a new study of Gaia satellite data, the nearest star collection to our Solar System is currently torn apart – disturbed not only by conventional processes, but also by gravitational pull- mind something big that we will never see.
This riot, astronomers say, could lead to the impression that an invisible lump of dark matter is nearby, destroying gravitational damage to anything that is accessible.
In fact, star clusters are inevitable to be dismantled by gravitational forces. A collection of stars, as the name suggests, is a tight, dense density of stars. Even internally, the gravitational interactions can be quite stormy.
Between these interactions with external galactic tidal forces – the pressure exerted by the galaxy itself – star clusters can be pulled apart in star-shaped rivers: something like called a tidal current.
These currents are difficult to see in the sky, as stellar distances are often difficult to measure, so group stars together. But the Gaia satellite has been working to map the Milky Way galaxy in three dimensions with the most accurate and highest achievable information, and the most accurate positioning and distance data on as many stars as possible.
Because stars drawn from a star group still share the same distance (more or less) as the stars into the collection, the Gaia data has helped astronomers identify many previously unidentified tidal currents, and star-studded tusks – strands of stars that have begun to emerge from the group both in front of and behind him.
In 2019, astronomers revealed they had found evidence in the second Gaia data release of tidal tails emanating from the Hyades; at 153 light-years away, it is the closest star cluster to Earth.
This caught the attention of astronaut Tereza Jerabkova and her colleagues from the European Space Agency and the Southern European Observatory. When Gaia Data Release 2.5 (DR2.5) and DR3 became available, they came in, expanding the scan parameters to capture the stars that the earlier detections were missing.
They found hundreds and hundreds of stars associated with the Hyades. The main group is about 60 light-years across; the tidal tails cycle thousands of light years.
Getting tails like that is pretty normal for a star browser bothered by tidal forces, but the team noticed something strange. They ran symbols of the cluster riot, and found many more stars in the tail of the simulation slash. In the real group, some stars are missing.
The team ran more simulations to find out what might cause these stars to stray – and found that interacting with something large, about 10 million times the mass of the sun, the surprise seen.
“There must have been a close interaction with this horrible lump, and the Hyades just broke,” Jerabkova said.
The big problem with that situation is that we don’t currently see anything major anywhere nearby. However, the Universe is full of invisible matter – a dark matter, the name we give to the mysterious mass that we can only determine by its gravitational effects on what we see.
Based on these gravitational effects, scientists have found that about 80 percent of everything in the Universe is a dark matter. Dark matter is thought to be an essential part of galaxy creation – large lumps of it early in the Universe gathered their usual shape into the galaxies we see today.
Story diagram of our galaxy dark subject halo. (Digital World / American Museum of Natural History)
These lumps of dark matter are found today in expanded ‘dark halos’ around galleries. The Milky Way is estimated to be 1.9 million light-years across. Inside these halos, astronauts predict dense lumps, called subhalos of dark matter, just moving around.
Future investigations could turn up a potentially extinct structure of stars in Hyades’ s slender tail; if they do not, the researchers believe the riot could be a dark case subhalo work.
The discovery also suggests that tidal currents and tidal tails could be great places to look for sources of secret grave interactions.
“With Gaia, the way we see the Milky Way has completely changed,” Jerabkova said. “And with these findings, we will be able to map the Milky Way substructures much better than ever before.”
The research was published in Astronomy & Astronomy.