CLASSICAL MECHANICS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site radial velocity Image credit: CSIRO Australia The speed at which an object is moving away from or toward an observer along the line of sight. By convention, it is positive if receding, negative if approaching. Radial velocity can be calculated from the displacement of spectral lines from their normal position: a object moving toward us has a blueshifted spectrum, while an object moving away has a redshifted spectrum. The larger the blueshift or redshift, the larger the radial velocity. The present radial-velocity champion for a star in the Milky Way Galaxy is Giclas 233-27 in Lacerta, which is approaching us at 583 km/s. External galaxies and, especially, quasars, may show very large recessional radial velocities due to the overall expansion of the universe. Compare with transverse velocity. Related categories    • CLASSICAL MECHANICS    • ASTRONOMICAL QUANTITIES Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP