The mass of the Milky Way is much smaller than expected
© APA/KEYSTONE/Anthony Annex / Anthony Annex
the Gaia Space Telescope It has been scanning our galaxy for nearly 10 years and with unprecedented precision Accuracy. The latest Gaia data set now indicates that the Milky Way is much lower Total size It was accepted.
Until now, it was assumed that the total mass of our spiral galaxy was approx 1.5 trillion solar masses He lies. However, according to the latest calculations, the mass of the Milky Way should be “only” 200 billion solar masses Lying down.
This is coming out One Stady Outsidecreated by astronomers at the Paris Observatory.
➤ Read more: The European Space Agency reveals stunning new images of star clusters and quasars
Differences in rotation speed
Calculations indicate movements of approx 2 billion starsIt is the most accurate to date Rotation curve A spiral galaxy has been created. Accordingly, it takes Rotational Speed The farther away they are from the center of the Milky Way.
This is how they act Milky Way stars Unlike stars in other galaxies. There is such acceptance in Rotational Speed We do not notice, he writes Haze.
The fact that this speed remains the same externally forms the basis for this Dark matter theory It is considered one of the most important discoveries in modern astronomy. So it’s supposed to be dark matter Acceleration Who are the stars.
➤ Read more: Astronomers find the edge of the Milky Way
Much less dark matter?
So, if the rotation speed of stars in the outer Milky Way is slowing down, then so is our galaxy Much less dark matter He has more than he assumes. With a solar mass of 200 billion, only about two-thirds of this mass could be dark matter.
But the question now is how will all this end? Because that Traditional issue In the Milky Way About 60 billion solar masses She informs. It has been assumed so far that there must be at least 6 times as much dark matter as there is in conventional matter.
➤ Read more: Discovery of more than 1,000 ancient “Milky Ways”: Researchers are at a loss
A revolution in astronomy?
If the new calculations conducted by the French research team are confirmed, this will happen A revolution in astronomy Now, write it down Scientific American magazine.
But all this can have completely different reasons. For example, it may be possible that the differences are due to… Methodological differences in calculation Rotation curves between our home galaxy and distant galaxies.
Differences can also be due to comparison Quiet story The Milky Way, writes the research team. the last Big collision With another galaxy much further away in the case of the Milky Way than is the case with other spiral galaxies.
➤ Read more: The 3D map shows a cosmic web connecting galaxies