|Space Telescope Science Institute|
|FGS Instrument Handbook Cycle 23|
A short summary is given for each FGS1r calibration and monitoring observation included in the Cycle 21 calibration plan. For specific information, please refer to the STScI FGS Web page (under the topic FGS and Calibration Plans”) and to the HST Schedule and Program Information Web page:
- This proposal uses FGS1r in POS mode to observe selected stars in M35 to obtain astrometric data used to update the values of the star selector servo parameters rhoA and kA, which are used to convert raw star selector encoder values to the local FGS (x,y) detector frame. Moreover, these data also allow both an on going monitoring of the OFAD calibration as well as updates to the M35 catalog accounting for proper motion of the observed stars. In this cycle, this program is one HST orbit that executes in August 2014, as that is the only time that FGS1r is used as a science instrument in POS mode (for the currently executing science programs).
- This is a two orbit HST proposal using FGS1r to observe two bright stars in the Hyades. These stars are approximately 90" apart. FGS1r is used to observe each star several time, alternating between F583W and F5ND, to measure the cross-filter shift (wedge effect) of the star's position. Orbit #1 places one of the stars at FGS1r center to update the Transfer mode S-curve library, as well as the F5ND-F583W wedge effect at pickle center. The HST orient is chosen such that second star is placed in the vicinity go the FGS FOV where science targets have been observed using the F5ND attenuator. The second HST orbit places the two stars in the vicinity of where other science programs observed science targets with the F5ND. The required HST orients cause these visits to schedule in late 2013.