CELESTIAL 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 position angle Two measures of a binary star are separation and position angle. The directions shown here are for an inverting scope, such as a Newtonian reflector. Credit: Sky & Telescope Also known as parallactic angle, the direction of an imaginary arrow in the sky, measured in degrees from north through east; in other words, the angle between a body's hour circle and its vertical circle. Applied to a binary star system, it is the angle between the primary and secondary components of a binary system. Applied to a galaxy, it measures the object's tilt, that is, the angle between the galaxy's long axis and a line from its center headed north. Related category    • CELESTIAL MECHANICS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP