A galaxy consisting of a flattened rotating disk of young stars, a central bulge of generally older stars, and a surrounding halo of older stars and dense clusters of old stars called globular clusters The disk is prominent due to the presence of young, hot stars in a spiral pattern
A group of roughly stars, arranged with an ellipsoidal centre of old stars and a sparser thin disk of younger stars The core can be collisional, the disk is generally not
a highly flattened galaxy with a disk and a central bulge The disk has a spiral pattern with slightly more stars and gas than in the rest of the disk A slow, steady star formation rate means that they still have gas and dust left in them from which stars are still forming The star orbits are constrained to stay within a small distance from the mid-plane of the disk and have small eccentricities
large system of stars and interstellar matter having the shape of a flattened disk with outlying spiral arms
A galaxy with an obvious disk component containing gas; dust; hot, bright stars; and spiral arms
One of the three major classifications of galaxies; their characteristics include a plate-shaped disk containing spiral arms
A galaxy that contains a prominent central bulge and luminous arms of gas , dust, and young stars that wind out from the central nucleus in a spiral formation Our galaxy, the Milky Way, is a spiral galaxy
A galaxy with an obvious disk component containing gas; dust hot, bright stars; and spiral arms
a galaxy having a spiral structure; arms containing younger stars spiral out from old stars at the center