A few days ago, astronomers have increased the accuracy of the Hubble constant , which measures the expansion rate of the Universe.Now a team of Japanese astronomers has made new measurements of our own galaxy, which led to a refinement of this mass of dark matter in the Milky Way.They came to two main conclusions.
The first is that the distance from our solar system to the center of the galaxy is 26.1 light years away – a light year is a distance measure, which is equivalent to approximately 9.5 trillion miles.
The second conclusion is that the rate imposed on the solar system by the rotation of the Galaxy is approximately 240 km / s.This means that it takes 200 million years for the solar system complete a “orbit” around the galactic center.
Mass dark matter
The value now measured 240 km / s is known as V0. The currently accepted value for V0 is 220 km / s, having been established by the International Astronomical Union in 1986.In general, the rotation speed of the galaxy is determined by the balance with gravity galactic – thereby measure the rotation of the galaxy is equivalent to measuring the mass of the galaxy.
When data from the new survey were used to recalculate the value of V0, astronomers found that the mass of dark matter in the Milky Way is 20% higher than the accepted value today.According to the researchers, this value has a direct impact on the experiments that have been trying, so far unsuccessfully, to detect dark matter particles.
Mareki Honma and colleagues at the National Observatory of Japan used the project VERA ( VLBI Exploration of Radio Astrometry ) to measure precise distances and motion of celestial objects 50 to get the gain accuracy.