Current Events 2009

Summary-

Andromeda’s little brother, the Milky Way galaxy, has just been found to be pretty big. In fact, the galaxy is estimated to hold up to 3 trillion suns. Therefore, two of the biggest galaxies may smash into each other sooner than expected. To see the galaxy, scientists use the Very Long Baseline Array of ten radio telescopes that can enable astronomers to see through dusty byways. Mark Reid and his 20 colleagues based observations on twenty star formations across the galaxy by methanol masers. Masers need very high temperatures of star forming regions and the astronomers used them when the earth is at opposite sides of its orbit. These measurements were very accurate measurements of the motion across the sky as they orbit the galactic center. From these measurements Reid figured out that the Milky Way spins at a rate of 254 kilometers/second; fifteen % faster than last calculation. Using Newton’s law of gravity, the Milky Way is fifty % heavier; making it almost Andromeda’s weight. Since the increase of the galaxies weight and spin speed is matched with the other galaxy, they will collide much sooner. Most star formation in our galaxy takes place in the Milky Way’s spiral arms, where gas is compressed, triggering the birth of stars. The scientists also learned that the Milky Way had four spiral arms: two dominant ones and two weaker ones. This is a great advantage in our astronomy research. We now for the first time have full three-dimensional information, both location and velocity.

Work cited- http://www.sciencenews.org/view/generic/id/39709/title/This_just_in_Milky_Way_as_massive_as_3_trillion_suns