With the launch of HETE-2, it is expected that the bulk of GRB imaging will be using error circles which fit inside the frames of typical amateur CCD cameras. From time to time, it may be necessary to image error circles which exceed the capacities of the amateur camera. According to Arne Hendon, we must be prepared to image error circles up do a diameter of 20 arc-minutes.
The image at right shows a red 20 arc-minjute diameter circle superimposed on an arbitratry segment of sky. concentric with this circle is a reticle for my ST-9 camera (focal length 2022 mm objective). If imaging were done this way, a central section plus four wings would have to be imaged. This is pretty inefficient. A better way to approach the problem is represented by the two offset white boxes. One I will call North, and the other I will call South. As you can see, the error circle area is covered with two images.
