velocity Comparison Table

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velocity comparison table

Subject has synonym has definition

equatorial velocity The velocity at the surface of a rotating body, on its equator

escape velocity The velocity that a body requires to achieve a parabolic orbit around its primary (V_e = sqrt(2GM/R)). Escape velocity at Earth's surface is 11.2 km s^-1; of Moon, 2.4 km s^-1; of Sun, 617.7 km s^-1 (cf. orbital velocity).

galactic velocity component One of three components of a star's motion with respect to the center of a galaxy.

galaxy peculiar velocity A deviation in the velocity of a galaxy from that expected on the basis of a uniform expansion of the universe. (See Hubble law.)

orbital velocity Velocity required by a body to achieve a circular orbit around its primary: V_orb = (GM / r)^1/2.

peculiar velocity Velocity with respect to the Local Standard of Rest.

radial velocity The speed at which an object moves toward or away from us. It can be measured from a star's spectrum: a star moving toward us has a blueshifted spectrum, and a star moving away from us has a redshifted spectrum. The larger the blueshift or redshift, the larger the radial velocity. The present radial-velocity champion is a star in the constellation Lacerta named Giclas 233-27, which moves toward us at 583 kilometers per second.

space motion Velocity of a star with respect to the Sun; hypotenuse of the right triangle formed by its radial and tangential velocities (cf. peculiar velocity). Space motion vectors are U (in the direction of the galactic anticenter), V (in the direction of galactic rotation), and W (in the direction of the galactic north pole).

tangential velocity transverse velocity A star's velocity across an observer's line of sight. To calculate a star's tangential velocity, one must know the star's distance and proper motion.

Subject	has synonym	has definition
equatorial velocity		The velocity at the surface of a rotating body, on its equator
escape velocity		The velocity that a body requires to achieve a parabolic orbit around its primary (V_e = sqrt(2GM/R)). Escape velocity at Earth's surface is 11.2 km s^-1; of Moon, 2.4 km s^-1; of Sun, 617.7 km s^-1 (cf. orbital velocity).
galactic velocity component		One of three components of a star's motion with respect to the center of a galaxy.
galaxy peculiar velocity		A deviation in the velocity of a galaxy from that expected on the basis of a uniform expansion of the universe. (See Hubble law.)
orbital velocity		Velocity required by a body to achieve a circular orbit around its primary: V_orb = (GM / r)^1/2.
peculiar velocity		Velocity with respect to the Local Standard of Rest.
radial velocity		The speed at which an object moves toward or away from us. It can be measured from a star's spectrum: a star moving toward us has a blueshifted spectrum, and a star moving away from us has a redshifted spectrum. The larger the blueshift or redshift, the larger the radial velocity. The present radial-velocity champion is a star in the constellation Lacerta named Giclas 233-27, which moves toward us at 583 kilometers per second.
space motion		Velocity of a star with respect to the Sun; hypotenuse of the right triangle formed by its radial and tangential velocities (cf. peculiar velocity). Space motion vectors are U (in the direction of the galactic anticenter), V (in the direction of galactic rotation), and W (in the direction of the galactic north pole).
tangential velocity	transverse velocity	A star's velocity across an observer's line of sight. To calculate a star's tangential velocity, one must know the star's distance and proper motion.

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