Milky Way galaxy. Computer artwork of our Milky Way galaxy from above, with the arms and the central bar in their approximate known locations. The Milky Way is around 100,000 light years across and contains hundreds of billions of stars. There are four major arms, and one arm fragment (Orion-Cygnus) where the Sun is found. In the annotated version of this image (C004/9465), the yellow dot indicates the position of the Solar System, about 25,000 light years from the galactic core. The Norma and Outer arms are in fact the same, but the two names refer to different parts of it. The same is true of the so-called 3kpc (3 kilo-parsec) arm, which further out becomes the Perseus arm.