Cycle 8 Calibration

The Cycle 8 calibration plan was modeled closely on the Cycle 7 calibration plan. Once again, supported modes are to be monitored for such things as sensitivity changes, flat field evolution, and dispersion solutions. No additional calibrations were taken for most available-but-unsupported configurations. Observers wishing to use non-standard configurations should assess their calibration needs and include time in the proposal for any additional calibrations that are required.

In addition to monitoring instrument health and safety and maintaining the overall calibration of STIS supported modes, our special goals were as follows:

1. to improve the imaging throughput calibration accuracy (to better than the current 5% systematic uncertainty);
2. to improve PSF characterization in imaging mode and in coronographic mode;
3. to improve CCD hot-pixel and bias subtraction;
4. to improve the CCD charge transfer efficiency (CTE) characterization for sparse fields at low count levels;
5. to calibrate the dispersion as a function of position for MAMA slitless spectroscopy with the L-mode gratings;
6. to characterize observations with the FUV-MAMA repeller wire turned off, with the aim of possibly making this available for Cycle 10. This should improve the spectral resolution at the expense of a ~35% loss of sensitivity.

Links to the Phase II proposals giving full details of the observations can be found on the STIS web site under the "Cycle 8 Calibration Plan".