The Milky Way Galaxy is a disturbing discovery
It will be less massive than expected and its rotation curve will be atypical compared to other spiral galaxies.
Our Milky Way, a magnificent spiral galaxy.
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In astrophysics, we often seek to solve mysteries at the edges of the universe. But it is not always necessary to go far in time and space to confront the inexplicable. Even our own galaxy, the Milky Way, provides an example, and is particularly difficult. This would actually be less massive than previous calculations suggested, with a total mass equivalent to 206 billion times that of the Sun. A factor four to five times lower than all previously released estimates.
We know this thanks to the maps produced by the Gaia space mission, which launched in 2013. Thanks to its two telescopes, the Gaia satellite made a detailed survey of all the stars of the Milky Way, and patiently listed them by assigning them to each type. From the ID card.
Invisible matter
As far as our Galaxy is concerned, this new value, revised downward, may mean that the Milky Way finally contains less dark matter than we thought. As a reminder, dark matter is invisible, and can only be detected through the gravitational effects of surrounding stars. This explains why galaxies are stuck together, and especially why they are so fast. Dark matter, on the other hand, has never been officially proven, and remains hypothetical to this day.
But in addition to this modified block below, there is another piece of data that throws all the calculations into chaos. The Milky Way Galaxy, as we know, is one of the spiral galaxies. A study published at the end of September in the Journal of Astronomy and Astrophysics revealed that its rotation curve is indeed unusual. They are not flat, as is usually the case with spiral galaxies, but they begin to decay quickly.
The so-called “Keplerian” decay because it follows Kepler’s laws which, as we recall, determine the rotation of satellites according to their distance from the main body. Quite simply, the farther a satellite is from the object it is orbiting, the lower its rotation speed, which is quite logical. A law that applies, for example, to the planets of our solar system.
Amazing observation
Hence the amazement that astrophysicists were able to discover this information resulting from mapping and observations of the Gaia satellite. To the point of questioning whether the famous dark matter actually exists. Everything here is just speculation and theories. They are too many to mention in these pages.
Even strange hypotheses have appeared. Such as the one who assumes the existence of antigravity to describe some particles. This would stimulate the presence of negative masses in the universe and exclude the interference of any dark matter or energy. Please note that the probability of this hypothesis being true is very low.
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