Aligning Hubble Images

This graphic shows an example of how the Hubble Source Catalog was constructed for a small part of the Hubble Deep Field. The catalog includes data from 76 separate images for the same region. Only three of these original images are shown on the left: one taken in orange light by the Wide Field Planetary Camera 2 (top); one taken in blue light by the Advanced Camera for Surveys (middle); and one taken in infrared light with the Wide Field Camera 3 (bottom). Note that the "sources," or objects, in each original image are not perfectly aligned with the final position from the Hubble Source Catalog (the pink circles). Specially developed software had to shift all the images slightly to align the sources before making the final version of the catalog.