NGC 2549 is an example of a lenticular
galaxy, seen nearly edge-on. Lenticular galaxies are disk
galaxies without visible spiral structure, and get their name
because they often resemble a lens seen edge-on. In the Hubble
classification, they are regarded as an intermediate between
spiral and elliptical galaxies. Three structural components
frequently seen in galaxies are pronounced in this image: a
bright central disk, a bright central envelope, and a faint
extended envelope. Several smaller galaxies can be seen in this
image; such companion galaxies are common around large galaxies.
