Milky Way - Structure

Structure

A false-color infrared image of the core of the Milky Way Galaxy taken by NASA's Spitzer Space Telescope. Older cool stars are blue, dust features lit up by large hot stars are shown in a reddish hue, and the bright white spot in the middle marks the site of Sagittarius A*, the super-massive black hole at the center of the Galaxy.

The Galaxy consists of a bar-shaped core region surrounded by a disk of gas, dust and stars. The gas, dust and stars are organized in roughly logarithmic spiral arm structures (see Spiral arms below). The mass distribution within the Galaxy closely resembles the SBc Hubble classification, which is a spiral galaxy with relatively loosely wound arms. Astronomers first began to suspect that the Milky Way is a barred spiral galaxy, rather than an ordinary spiral galaxy, in the 1990s. Their suspicions were confirmed by the Spitzer Space Telescope observations in 2005 that showed the Galaxy's central bar to be larger than previously suspected.

Read more about this topic:  Milky Way

Famous quotes containing the word structure:

    “When a house is tottering to its fall,
    The strain lies heaviest on the weakest part,
    One tiny crack throughout the structure spreads,
    And its own weight soon brings it toppling down.”
    —Ovid (Publius Ovidius Naso)

    “Man is more disposed to domination than freedom; and a structure of dominion not only gladdens the eye of the master who rears and protects it, but even its servants are uplifted by the thought that they are members of a whole, which rises high above the life and strength of single generations.”
    —Karl Wilhelm Von Humboldt (1767–1835)

    “For the structure that we raise,
    Time is with materials filled;
    Our to-days and yesterdays
    Are the blocks with which we build.”
    —Henry Wadsworth Longfellow (1809–1882)