Using data from the Gaia Space Telescope, employees of Lund University in Sweden found that large parts of the Milky Way external disk were vibrating. It turned out to be caused by a dwarf galaxy that can now be seen in the constellation of the Arrower.
The Milky Way has between 100 billion and 400 billion stars. Astronomers believe that the galaxy was born 13.6 billion years ago, emerging from a spinning cloud of gas that consists of hydrogen and helium. For billions of years, the gas has been collected in a spinning disc where stars like our sun have formed.
Using data from the European Gaia Space Telescope, the research team studied a much larger area of the Milky Way Disc than before, measuring how strong the ripples were in different parts of the disk, the researchers understood how it appeared.
Scientists were surprised to learn how much of the Milky Way they were able to study using Gaia data. To date, the telescope that has been operating since 2013 has measured the movement of about two billion stars across the sky.