Milky Way is much ‘lighter than’ previous assumptions
Milky Way – our galaxy is a way much lighter than the previously believed mass of three trillion times bigger than that of sun, according to new study by British-based scientists.
Scientists at University of Edinburgh have published a detailed report on their latest research on Wednesday, that the mass of the galaxy that contains our solar system, calculated for the first time ever, to be just 800 billion solar masses, that is only half the mass of one of our neighbour Andromeda, 2.5 million light years away.
Until now, scientists believed the Milky Way and Andromeda to weigh the same, due to the similar spiral structure and somewhat the same size. But, after determining the accurate method to calculate the mass of galaxies, the scientists have found that Andromeda is actually twice as heavy as our Milky Way.
“We always suspected that Andromeda is more massive than the Milky Way, but weighting both galaxies simultaneously proved to be extremely challenging,” said Doctor Jorge Penarrubia, who led the study.
Our study combined recent measurements of the relative motion between our galaxy and Andromeda with the largest catalogue of nearby galaxies ever compiled to make this possible.
“We couldn’t believe it,” said Yin-Zhe Ma, a postdoctoral fellow in University of B.C, department of physics and astronomy. “We went back and checked our equations very carefully.”
Researchers believe that the extra mass of the Andromeda galaxy is due to the presence of more invisible dark matter – which according to NASA is the mysterious material that comprises around 80% of the matter in universe. Andromeda is believed to contain twice as much dark matter as Milky Way. However, 90% of the matter in both galaxies – Andromeda and Milky Way is invisible and researchers have been unable to prove which of the galaxies is larger.
The finding of the recent study is backed by the University of Cambridge’s research that reached a very similar result using a different set of data.