13.5	The Location of COS in the HST Focal Plane

The location of the COS aperture in the HST focal plane is shown in Figure 13.28. Note the relative orientation of the HST V2 and V3 axes (the V1 axis is along HST’s optical axis), as well as the relative locations and orientations of the other instruments. The COS aperture lies ~ 325 arcsec from the V1 axis in the +V2, −V3 quadrant.

Figure 13.28: A Schematic View of the HST Focal Plane

This drawing shows the entire HST focal plane and the apertures of the scientific instruments. The view is from the rear of the telescope looking forward toward the sky, the opposite of the sense of Figure 13.29.