AST 443: Charge Coupled Devices

Charge Coupled Devices, or CCDs, are the workhorse of optical astronomical instrumentation. For many purposes they are as close to an ideal detector as we can get. They feature:

Portions of an 1100 second HST/WFPC2 PC image through the F606W filter. The left panel shows imperfect CTE (the vertical band through the right star) and bleeding from an overexposed star; the right panel shows cosmic rays around an elliptical galaxy

CCDs do have defects. These include:

You can find specifics about how CCDs work in the textbook, in the Howell book, or at this website. A good physical introduction to CCDs is at this site (a pdf file).