NICMOS Focus After January '98 NIC3 Campaign

After the first NIC3 campaign, the HST secondary mirror was reset to its nominal position which differed by only +0.5 micron from the pre-NIC3 campaign setting. The data from the focus monitoring program obtained on February 1st, 1998, right after refocussing of the secondary mirror, suggests that the foci in all three cameras have moved back to the expected positions.

The focus history Table and the plot contain FOM corrections of -1.5 mm applied to all focus results for NIC1 and NIC2 obtained between days 351 through 397. Prior to and after that time frame, the FOM position for these two cameras is nominal.