Page History
The first four cluster/blank field pairs were observed with Director's Discretionary time in Cycles 21 and 22. After obtaining initial results from those data, observations of the final two cluster/blank field pairs were approved for execution in Cycle 23. For each cluster/parallel blank field, HST obtained WFC3/IR and ACS images simultaneously at a fixed position angle, then rolled and swapped camera positions roughly 6 months later.
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