For the first time, an accurate weight of our galaxy was determined by studying the star cluster, which orbit the Milky Way
Despite years’ worth of space research, there is still a lot of ambiguity regarding the overall knowledge about the outer space. In recent times, astronomers and scientists have been making some fast paced advancements towards ascertaining the mysteries of the universe. Dark matter studies, detection of black holes and other such achievements, off late, have contributed to a better understanding of the cosmic world. Now, for the first time, astronomers believe they have accurately weighed the mass of the entire galaxy in which we reside.
Although there have been previous estimates regarding the mass of the Milky Way, no other method has been as precise as this one. The scientists made use of the data from both the Hubble Space Telescope and the Gaia Satellite to make an accurate measurement. They did so by observing the globular cluster, aged star clusters that orbit the Milky Way. Previously, the mass of the galaxy was estimated to lie in the range of 500 billion solar masses to 3 trillion solar masses, where one solar mass is equivalent to the weight of the sun. The new method, however, suggests that the Milky Way is clocking in at 1.5 trillion solar masses.
The most absurd fact about this number, is that a majority of this mass is unobservable. The billions of stars and the supermassive black hole at the center of the galaxy, constitute only a very small part of the universe’s weight. The rest of it is made up by the mysterious dark matter, which although is unobservable in nature, can be detected by the gravitational disturbances it causes on the surrounding objects.
“We want to know the mass of the Milky Way more accurately so that we can put it into a cosmological context and compare it to simulations of galaxies in the evolving universe,” says Roeland van der Marel, an author of the study, published in the Astrophysical Journal, on March 8, 2019.