16466

Observations of the spectrophotometric white dwarf standard star WD0308-565 will be obtained at all cenwaves that are moving to LP5 comma and G140L-800 comma which is moving to LP3. All FP-POS will be used for the observations except for G130M-1291-FUVB comma for which only FP-POS=3 comma 4 will be used in order to comply with the COS2025 rules. The data will be used to determine the 2D cross-dispersion spectral profiles and traces required to perform two-zone extraction comma as well as the sensitivities and flat-fields for accurate flux calibration. Additionally comma the data will be used to determine the spatial resolution of the detectors. The main requirement for this program is to achieve S-N of about 50 per resel comma which is driven by the requirement for obtaining profiles that are sufficiently accurate that the contours can be located such that the enclosed flux errors are less than 1%. This program ties in with the FUV spectroscopic sensitivity monitoring program at LP4 during which near-contemporaneous observations at the new LPs will be obtained to monitor any rapid evolution in the gain.