During Kepler’s commissioning phase in April 2009, the spacecraft observed 33,424 stars in a dither pattern for the purpose of measuring the Pixel Response Function (PRF). The pattern consisted of 122 pointings, each with a duration of 14.7 minutes, observed across a 2.5-day period on April 27-29, 2009.
The PRF inferred from these data was previously released in the form of FITS files which provide PRF images for the four corners and the center of each CCD channel. These files have been available from the Kepler data archive's Focal Plane Characteristics page for several years, and their construction was detailed in a paper by Bryson et al. 2011.
The dithered data from which the PRF was inferred was hitherto unavailable. As part of an ongoing effort to unearth all useful data before the end of the mission, these cadences have been processed into Target Pixel Files and are now available from the data archive at MAST for the first time. They may be of use to anyone wishing to investigate Kepler's intra- and inter-pixel variations. Details of this release are described in document KSCI-19100.
The animation below shows example data obtained as part of the dither sequence. The graph elucidates the dither pattern (Figure 3 from Bryson et al. 2011).