How To Use Variable Star Charts The following text is taken in part from the Manual for Visual Observing of Variable Stars What Scale to Use?
On this photographic plate of the Andromeda Nebula (the image is a negative with stars appearing as black dots against the background of white space), Edwin Hubble found and marked several suspected novae with the letter “N”. Later he discovered one of these was actually a cepheid variable – crossing out the “N” he wrote “Var!” in the upper right hand corner. Image Credit: Mount Wilson Observatory, Historical Archive Using the method described below, new observers should ascertain the approximate size of the field of view of their telescopes with the different eyepieces. Point the telescope at a region not far from the celestial equator and without moving the instrument allow a bright star to trail through the field. The star will move at a rate of one degree in four minutes, near the equator. For example, if two minutes are required for the star to pass across the center of the field, from edge to edge, the diameter of the field is one-half of one degree. Once the instrument’s field i
