. Use astrophysicsformulas for physics, astrophysics assignment and homework help, test prep, exam prep, and as a study aid or memory jogger. In astronomy, annual parallax is the only direct way to measure distance to stars outside the solar system.In essence, parallax is the perceived shifting phenomenon which occurs when an object is viewed from different positions. \]. //-->, . Use astrophysicsformulas for physics, astrophysics assignment and homework help, test prep, exam prep, and as a study aid or memory jogger. In astronomy, annual parallax is the only direct way to measure distance to stars outside the solar system.In essence, parallax is the perceived shifting phenomenon which occurs when an object is viewed from different positions. \]. //-->,