Astronomers still don't know how the phenomenon began. They also don't know whether it's rare or more common in our Milky Way and beyond. But they certainly observed the Radcliffe Wave stars moving up and down on either side of our spiral arm. Like fans playing at the Ola stadium!
A few years ago, astronomers from the Harvard Radcliffe Institute (USA) observed for the first time a strange and huge structure of gas and dust in the heart of the Milky Way. Well, strictly speaking, not quite “at heart”. The one that researchers quickly dubbed the Radcliffe wave is actually developing in our galactic neighborhood. Up to just 500 light-years from our solar system at its closest point. And it looks like a band about 9,000 light-years long and about 400 light-years wide where star clusters form.
Milky Way: A mysterious giant wave would have created swarms of stars
Researchers at the Harvard Radcliffe Institute have just made a surprising new discovery regarding this structure. They report in the journal Nature that the Radcliffe wave not only clearly represents the ripples of a wave above and below our Milky Way, but that it is actually moving. A bit like the stars that make it up thought they were fans in a stadium and made Ola!
The Radcliffe Wave oscillates up and down
The discovery was made possible by new data sent back by the Gaia satellite. Astronomers were able to extract the positions and motions of star clusters present in the Radcliffe wave. And conclude that the giant structure moves like what physicists call a traveling wave. Understand that star clusters move up and down along the Radcliffe Wave. “Just as fans in a stadium are pulled back to their seats by Earth's gravity, the Radcliffe wave oscillates due to the Milky Way's gravity,” explain astronomers at the Harvard Radcliffe Institute.
This discovery will allow researchers to test the various theories they have put forward so far about the origin of the Radcliffe wave. From massive stellar explosions to extragalactic disturbances, like the collision of a dwarf satellite galaxy with our Milky Way.
This movement of the Radcliffe Wave raises questions
The work published today also raises the question of the influence of dark matter on the newly observed oscillatory motion of the Radcliffe wave. But researchers are clear on this topic. The gravity of ordinary matter alone is enough to cause the movement of Ola.
Enough to raise new questions. Are such waves rare or, on the contrary, widespread elsewhere in our Milky Way? In the UniverseUniverse? What caused the movement that led to the excitement observed by astronomers? Does this happen every now and then? The whole time ? Because the Radcliffe wave appears to form the backbone of our Milky Way spiral arm, the waviness of this structure could indicate that the spiral arms of galaxies tend to oscillate. Enough to make galaxies even more dynamic than astronomers previously thought.