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.

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Famous quotes containing the word structure:

    “Vashtar: So it’s finished. A structure to house one man and the greatest treasure of all time.
    Senta: And a structure that will last for all time.
    Vashtar: Only history will tell that.
    Senta: Sire, will he not be remembered?
    Vashtar: Yes, he’ll be remembered. The pyramid’ll keep his memory alive. In that he built better than he knew.”
    —William Faulkner (1897–1962)

    “There is no such thing as a language, not if a language is anything like what many philosophers and linguists have supposed. There is therefore no such thing to be learned, mastered, or born with. We must give up the idea of a clearly defined shared structure which language-users acquire and then apply to cases.”
    —Donald Davidson (b. 1917)

    “The philosopher believes that the value of his philosophy lies in its totality, in its structure: posterity discovers it in the stones with which he built and with which other structures are subsequently built that are frequently better—and so, in the fact that that structure can be demolished and yet still possess value as material.”
    —Friedrich Nietzsche (1844–1900)