Asteroids Tutorial Background Subtracting is one way of manipulating images. This process eliminates stationary and non-changing objects such as stars and galaxies. The objects that remain could be several things, from supernovae to asteroids to cosmic rays to CCD chip defects. For novice users, we recommend doing every step in order.
Advanced users can proceed at any pace they find comfortable.
You may use the procedure to process other images at your own risk. Note that errors in subtractions do not usually make themselves apparent until the four steps have all been carried out and the subtraction has been made. For this reason, it is recommended that you note all numbers involved with your data , so that if you need to start over you won't have to do everything over again. The subtraction procedure utilizes the following two images, f1911534.fts and f1911538.fts . If you come to a point in your subtraction process where you need to save the images you are working with, it is generally best to save them under a new name .