optical observed frame

The optical observed frame is a system of reference used in astronomy to measure the position and motion of celestial objects. It is defined by the location of Earth and is based on observations made using optical telescopes. In this frame, the positions and velocities of objects are measured relative to the observer on Earth. This frame is used to study the motion of stars, galaxies, and other celestial objects in relation to our own planet. It is important in understanding the structure and evolution of the universe.