Our galaxy is mysteriously vibrating and scientists have just found out why
According to data collected by the Gaia satellite, the Milky Way is mysteriously undulating. Researchers have found the answer to this strange phenomenon.
Satellites are of great use in understanding the intriguing phenomena that are happening in our galaxy. This time, Gaia , developed by the European Space Agency (ESA) , was able to provide us with some crucial data about the Milky Way.
The Gaia satellite scans the stars
Located 1.5 million kilometers from our planet, it cannot therefore be disturbed by the Earth's magnetic field. Its data on the state of our galaxy are therefore very reliable. But then what happens in the ?cosmos
Well, according to a group of researchers from Lund University in Sweden who collected the data from Gaia , large parts of the Milky Way's outer disk are said to be vibrating . According to them, these ripples would have a link with the passage of a huge cosmic object which passed near our galaxy.
The stars of our galaxy in full ripple
Indeed, after analyzing the data collected by Gaia, the astronomers noticed that the stars present in the outer regions of the galactic disk were oscillating from one side to the other. Like a water lily would undergo the ripples of the water in a way. According to them, this movement back and forth would have been caused by the passage of a dwarf galaxy .
"We can see that these stars oscillate and move up and down at different speeds. When the dwarf galaxy Sagittarius passed the Milky Way, it created wave motions in our galaxy, much like dropping a stone in a pond ," says Paul McMillan, astronomy researcher at Lund Observatory and director of the study.
Our Milky Way and Sagittarius
These findings, published in Monthly Notices of the Royal Astronomical Society , provide us with vital information about the history of Sagittarius , and its orbit around our galaxy. Indeed, our system being much larger than this dwarf galaxy, Sagittarius is being eaten by our Milky Way . The law of the strongest in a way.
Paul McMillan abounds: "Currently, Sagittarius is slowly tearing apart, but 1 to 2 billion years ago it was much larger, probably about 20% of the mass of the Milky Way disc" , explains Paul McMillan.
According to astronomers, this discovery made by Satellite shows us that the Milky Way can now be studied in the same way that geologists study the Earth from the seismic waves that pass through our planet.
Source: websites