Astronomers give Milky Way size bump
Milky Way 50 per cent more massive than previously thought
Monday, 05, Jan 2009 06:56
Astronomers are hoping no one notices their minor adjustment to the mass of the Milky Way, which is 50 per cent bigger than previously thought.
Our galaxy is rotating around 100,000 miles faster than had been estimated, according to Mark Reid of the Harvard-Smithsonian Centre for Astrophysics.
He and his team of US scientists used the National Science Foundation's Very Long Baseline Array (VBLA) radio telescope to remake the map of our galaxy.
The studies involve observing regions of prolific star formation and using the bright landmarks they provide as a comparison with further away objects.
"The new VLBA observations of the Milky Way are producing highly-accurate direct measurements of distances and motions," said Karl Menten of the Max Planck Institute for Radio Astronomy in Germany, a member of the team.
"These measurements use the traditional surveyor's method of triangulation and do not depend on any assumptions based on other properties, such as brightness, unlike earlier studies."
The team has warned that, despite our galaxy no longer being the "little sister of the Andromeda Galaxy in our local group family", the Milky Way's greater mass is not good news.
The larger mass means a greater gravitational pull – increasing the likelihood of collisions with Andromeda or other nearby galaxies.