= Solution
Face-on, the <Milky Way> is a <barred spiral galaxy>: a central bulge and bar of scale a few kiloparsecs lie inside a disk of stellar radius roughly $15\,\mathrm{kpc}$, with spiral arms containing gas, dust, <H II regions> and young stars. Recent <star formation> is concentrated in molecular clouds and arm complexes. The <Sun> lies in the disk about $8\,\mathrm{kpc}$ from the centre in the source's convention. Old stars are also present throughout the disk, while the bulge, thick disk and extended stellar halo contain important old populations. <Globular clusters> occupy a roughly spheroidal halo extending well beyond the bright disk.
\Image[/past-exam-of-the-short-options-paper-shared-by-prelims-and-parts-a-and-b-of-the-physics-course-of-the-university-of-oxford/2012-s26-milky-way-structure.png]
{title=Original schematic face-on and edge-on views of the Milky Way}
{description=The face-on panel labels a barred centre, spiral star-forming regions, the Sun and an approximate 15 kpc bright-disk radius. The edge-on panel separates the thin dusty disk, thick disk, bulge and old halo/globular-cluster population. Halo extent is indicated schematically beyond the plotted field.}
Back to article page
