An enormous “wave” is rippling by way of our galaxy, pushing billions of stars in its wake, a brand new research reveals.
The Milky Way‘s galactic wave was noticed in mapping information from the European Space Agency’s (ESA) Gaia area telescope, which charted the positions and motion patterns of thousands and thousands of stars with excessive accuracy earlier than retiring earlier this 12 months.
Astronomers nonetheless do not know what began the movement. It might have been a previous collision with a smaller, dwarf galaxy that brought about the massive shake, ESA officers mentioned, however extra investigation is required to reply that query.
The outcomes had been revealed July 14 within the journal Astronomy & Astrophysics.
Mapping the wave
Gaia mapped the speeds and motions of stars for almost a dozen years. In 2020, the telescope noticed that the disk of the Milky Way wobbles like a spinning top. The newfound wave was charted by following the movements and positions of young, giant stars as well as a set of Cepheids — stars that have predictable-but-variable brightness.
“Because young giant stars and Cepheids move with the wave, the scientists think that gas in the disc might also be taking part in this large-scale ripple,” ESA officials wrote in the statement. “It is possible that young stars retain the memory of the wave information from the gas itself, from which they were born.”
ESA officials likened the galactic wave to “the Wave” done by a crowd at a stadium: In a group movement starting from one side of the stadium and moving section by section to the other side, individuals rise from their seats, fully stand up with their arms extended, and then sit back down.
A similar type of wave motion is visible when our galaxy is observed edge-on. Such vertical motions, represented by arrows, show ripples of movement far across the Milky Way’s disk.
“This observed behaviour is consistent with what we would expect from a wave,” lead author Eloisa Poggio, an astronomer on the National Institute of Astrophysics in Italy, mentioned within the assertion.
The newly found wave is also associated to a a lot smaller Milky Way ripple already identified by scientists. Called the Radcliffe Wave, it’s seen about 500 light-years from the solar and stretches for 9,000 light-years throughout area.
“However, the Radcliffe Wave is a much smaller filament, and located in a different portion of the galaxy’s disc compared to the wave studied in our work,” Poggio mentioned. “The two waves may or may not be related. That’s why we would like to do more research.”