Color Intensity Projections: A simple way to display changes in astronomical images

摘要

To detect changes in repeated astronomical images of the same field of view(FOV), a common practice is to stroboscopically switch between the images.Using this method, objects that are changing in location or intensity betweenimages are easier to see because they are constantly changing. A novel displaymethod, called arrival time color intensity projections (CIPs), is presentedthat combines any number of grayscale images into a single color image on apixel by pixel basis. Any values that are unchanged over the grayscale imageslook the same in the color image. However, pixels that change over thegrayscale image have a color saturation that increases with the amount ofchange and a hue that corresponds to the timing of the changes. Thus objectsmoving in the grayscale images change from red to green to blue as they moveacross the color image. Consequently, moving objects are easier to detect andassess on the color image than on the grayscale images. A sequence of images ofa comet plunging into the sun taken by the SOHO satellite (NASA/ESA) and HubbleSpace Telescope images of a trans-Neptunian object (TNO) are used todemonstrate the method.