With the help of the Hubble Space Telescope and Gaia, astronomers managed to get to the most accurate measure of the Milky Way’s mass to date. According to the numbers, our galaxy is just as massive as the Andromeda one. According to the new study, the mass of the Milky Way galaxy equals about 1.5 trillion Suns.
Laura Watkins from the Space Telescope Science Institute and her team used data collected by the Hubble Space Telescope for ten years, as well as data from the European Space Agency’s Gaia. They attempted to pin the motions of 46 globular clusters.
In the past other scientists also tried to measure the speed at which a cluster is moving towards or from our planet. “However,” said co-author N. Wyn Evans from the University of Cambridge “we were able also to measure the sideways motion of the clusters, from which the total velocity, and consequently the galactic mass, can be calculated.”
The mass of the Milky Way equals 1.5 trillion Suns
The mass of the Milky Way has always been a tricky topic for scientists. However, this new measurement is the most precise one so far. In the past, scientists were only able to estimate that the mass is somewhere between 0.5 trillion and 3 trillion Suns.
“Together with another analysis of similar data by Posti & Helmi, [this study] has tipped the scale towards a heavier Milky Way,” says Ana Bonaca from the Harvard-Smithsonian Center for Astrophysics. “Thanks to these studies, we now know that shallow value for the mass of the Milky Way is unlikely.”
Since it takes years of observations in order to understand the proper motions of the globular clusters, the data from the Hubble Space Telescope and the ESA’s Gaia mission was vital. The team discovered that the mass of the Milky Way galaxy is equivalent to 1.5 trillion Suns.
Jasmine holds a Master’s in Journalism from Ryerson University in Toronto and writes professionally in a broad variety of genres. She has worked as a senior manager in public relations and communications for major telecommunication companies, and is the former Deputy Director for Media Relations with the Modern Coalition. Jasmine writes primarily in our LGBTTQQIAAP and Science section.