Quantcast
Last updated on April 19, 2014 at 13:20 EDT
Halo of Andromeda Galaxy Used to Measure Its Drift Across
118 of 999

Halo of Andromeda Galaxy Used to Measure Its Drift Across Space

June 5, 2012
This composite image shows a region in the halo in the neighboring Andromeda galaxy that astronomers used to precisely measure the galaxy's sideways motion on the sky. This has allowed them to predict a direct collision between Andromeda and the Milky Way about 4 billion years from now. The inset image on the left is from a 2002 Hubble Space Telescope deep exposure that captured the light from 300,000 stars in Andromeda's halo, a vast spherical cloud of stars surrounding the galaxy's bright disk. Embedded in the image are numerous background galaxies that are much father away than Andromeda. Astronomers compared this region to pictures of the same area taken seven years later. They measured the tiny amount of sideways drift in the halo stars relative to the stationary background galaxy field. The same measurements were done for two other fields in the galaxy as well. This is similar to measuring the drift of a boat relative to a background shoreline. Object Names: M31, NGC 224, Andromeda Galaxy Image Type: Astronomical/Illustration Credit: NASA, ESA, R. van der Marel and T. Brown (STScI), and the Digitized Sky Survey

Topics: Large-scale structure of the cosmos, Large-scale structure of the cosmos, Large-scale structure of the cosmos, Extragalactic astronomy, Extragalactic astronomy, Extragalactic astronomy, Andromeda constellation, Andromeda constellation, Spiral galaxies, Spiral galaxies, Local Group, Local Group, Astronomy, Astronomy, Astronomy, ESA, ESA, ESA, ESA, ESA, National Aeronautics and Space Administration, National Aeronautics and Space Administration, National Aeronautics and Space Administration, National Aeronautics and Space Administration, National Aeronautics and Space Administration, Andromeda–Milky Way collision, Andromeda–Milky Way collision, Andromeda's satellite galaxies, Andromeda's satellite galaxies, Andromeda, Andromeda, Andromeda, Andromeda, Andromeda, Andromeda Galaxy, Andromeda Galaxy, Andromeda Galaxy, Andromeda Galaxy, Andromeda Galaxy, Unbarred spiral galaxies, Unbarred spiral galaxies, Unbarred spiral galaxies, Unbarred spiral galaxies, Unbarred spiral galaxies, Messier objects, Messier objects, Messier objects, Messier objects, Messier objects, Andromeda constellation, Andromeda constellation, Andromeda constellation, Galaxy, Galaxy, Galaxy, Galaxy, Galaxy, Milky Way, Milky Way, Milky Way, Milky Way, Milky Way, Spiral galaxies, Spiral galaxies, Spiral galaxies, Local Group, Local Group, Local Group