The latest research from astronomers suggests that the mass of the Milky Way mostly comes from dark matter while only a fraction of it comes from the nearly 200 billion stars in it.
Understanding the mass of the Milky Way is crucial for many cosmological concerns. According to Roeland van der Marel of the Space Telescope Science Institute (STScI), this will allow researchers to convert it to cosmological context and “compare it to simulations of galaxies in the evolving universe.”
To find out the mass of the Milky Way, researchers used information from the Hubble telescope and Gaia satellite. They were able to measure the cluster movements thanks to a three-dimensional map of the Milky Way created from the recorded positions of the stars. The results then suggested how much dark matter there really is in the Milky Way.
“The Milky Way weighs in at about 1.5 trillion solar masses (one solar mass is the mass of our Sun), according to the latest measurements. Only a tiny percentage of this is attributed to the approximately 200 billion stars in the Milky Way and includes a 4-million-solar-mass supermassive black hole at the center,” NASA said in a post.
“Most of the rest of the mass is locked up in dark matter, an invisible and mysterious substance that acts like scaffolding throughout the universe and keeps the stars in their galaxies,” the space agency added.
Measuring the Milky Way’s mass is not as easy as it sounds. Researchers needed to measure the velocities of globular star clusters. According to Tony Sohn from the STScI, who also lead the Hubble measurements, global clusters could be found at a great distance. Astronomers consider them as the best tracers to measure the galaxy.
This was not the only thing that the Hubble Space Telescope found. Recently, NASA also discovered “singing” galactic spiral arms and elliptical structures. Data from the telescope showed a stunning view of galaxies held together by gravity. When the researchers converted the data, they found that galaxies can “sing” or produce sounds.
The data recordings revealed the range of musical tones that stars can create. Specifically, sprawling spiral galaxies have longer notes that change pitch while compact galaxies and stars have short and clear tones.