Giant Rippling Wave Sweeping Across the Milky Way

Scientists have identified a huge and unexplained wave in the Milky Way.
a massive oscillation across the galaxy’s disk, pushing stars tens of thousands of light-years from the center.

The Milky Way doesn’t just rotate it also “ripples.”
The newly observed wave affects stars tens of thousands of light-years from the center.
Similar to ripples spreading from a stone thrown into water, this stellar wave extends across a large portion of the outer disk.

From these maps, the wave is seen extending over a vast part of the disk, affecting stars roughly 30,000 to 65,000 light-years from the center (the Milky Way’s diameter is about 100,000 light-years).

“The exciting part is that Gaia lets us measure the stars’ motions within the disk,” says Eloisa Poggio, an astronomer who led the team that discovered the wave.
From the side view of the Milky Way, the wave is represented in red and blue: red indicates stars above the warped disk, and blue indicates stars below it.

White arrows show the vertical components of the stars’ velocities.
The pattern of vertical motions matches the wave’s spatial pattern precisely.
Because these stars move with the wave, scientists believe that the gas in the disk also participates, suggesting that young stars retain a “memory” of the wave from the gas they formed from.

Researchers have discovered a vast and mysterious wave in the Milky Way.
European Space Agency’s Gaia space telescope show a large-scale oscillation across the galaxy’s disk, displacing stars by tens of thousands of light-years from the center. Scientists have identified a huge and unexplained wave in the Milky Way.

The Milky Way doesn’t just rotate it also “ripples.”
The newly observed wave affects stars tens of thousands of light-years from the center.
Similar to ripples spreading from a stone thrown into water, this stellar wave extends across a large portion of the outer disk.

From these maps, the wave is seen extending over a vast part of the disk, affecting stars roughly 30,000 to 65,000 light-years from the center (the Milky Way’s diameter is about 100,000 light-years).

“The exciting part is that Gaia lets us measure the stars’ motions within the disk,” says Eloisa Poggio, an astronomer who led the team that discovered the wave.
From the side view of the Milky Way, the wave is represented in red and blue: red indicates stars above the warped disk, and blue indicates stars below it.

White arrows show the vertical components of the stars’ velocities.
The pattern of vertical motions matches the wave’s spatial pattern precisely.
Because these stars move with the wave, scientists believe that the gas in the disk also participates, suggesting that young stars retain a “memory” of the wave from the gas they formed from.

The next Gaia data release (DR4) will provide even more accurate measurements of the positions and movements of Milky Way stars, including variable stars like Cepheids. “This will allow us to produce more detailed maps and deepen our understanding of these structures within our galaxy,” says Johannes Zalman, a Gaia project scientist at ESA.