0 PARALLELS SIGNIFICANTLY EXTEND ALIGNMENT TIME PARALLELS SIGNIFICANTLY EXTEND ALIGNMENT TIME Feb resubmission: visits 51,52 to repeat the failed visits 1,2. Visit Planner run only on repeat visits. Third submission try on Feb 21 (after exiting APT and bringing up a fresh instance). 1631566951 ----- Attempting Submission 1 (Fri Jan 24 19:18:15 GMT 2025) ----- ----- Attempting Submission 2 (Mon Feb 03 19:26:07 GMT 2025) ----- ----- Attempting Submission 3 (Fri Feb 21 19:10:14 GMT 2025) ----- HST Phase II Proposal 17893 successfully submitted. Receipt: # 17893-3 ----- Attempting Submission 4 (Fri Feb 21 20:36:12 GMT 2025) ----- HST Phase II Proposal 17893 successfully submitted. Receipt: # 17893-4 ----- Attempting Submission 5 (Fri Feb 21 20:46:10 GMT 2025) ----- HST Phase II Proposal 17893 successfully submitted. Receipt: # 17893-5 Investigators list is ignorable. As far as the parallels go, if they make the visits unschedulable, then we can tweak to drop the ACS parallels Impact of Single Star Guiding on HST Pointing Stabaility with WFC3/UVIS Reduced Gyro Mode (RGM) imposes significant orientation limitations on observations. Not only do observers have less freedom in choosing the orientation for their exposures, but sometimes there are no allowable orientations that have two guide stars. When there is a primary GS but no secondary GS, the telescope boresight can be held steady, but the telescope must rely on the gyro to hold the orient steady. Orient drift about the guide star in the FGS translates to pointing drift for the prime instrument. We have analyzed the pointing stability of available archival 1GS observations pre/post RGM, and we find no perceptible impact to image quality. As a result of this finding, all SNAPs have been converted to single-GS guiding. However, since SNAPs are typically <500s, it is hard to assess the impact of one-star guiding on longer exposures and visits. This proposed program will provide PIs with critical information to make better informed Phase-2 decisions regarding exposure length. To measure the stability of the pointing on single star guiding, we will observe a rich stellar field near IC 1848 (Soul Nebula) with WFC3/UVIS. We will obtain multiple undithered exposures (as any change in the pointing will thus be guiding error) in a single filter, and repeat the observations five times to validate the result. Additionally, we will obtain two ACS/WFC images in parallel at the end of each orbit to investigate the effects of single star guiding on the parallel instruments. Additionally, these observations will aid in constraining the focus of the observatory by allowing a much larger number of stars to be measured on more regions of the detectors, especially the corners in amplifiers A and D, where the focus variations are strongest. We observe a field offset south from the center of IC 1848 with WFC3/UVIS F410M. We avoid the center of the cluster due to the presence of two extremely bright (B~=7 mag) stars. Each of the five visits are identical. Each visit is to be separated by between 1 and 3 days to sample the behavior of the pointing control system. Each visit visit has the following structure of exposures - 35s UVIS F410M - 350s UVIS F410M - 350s UVIS F410M - 350s UVIS F410M - 350s UVIS F410M + ACS/WFC F606W in parallel - 350s UVIS F410M + ACS/WFC F606W in parallel This strategy allows for the collection of the most images in a visit, while ensuring adequate SNR on many stars in the field. The orient ranges are set to attempt to prevent bright figure 8 ghosts from affecting the data. In these observations, no dithers are used, as we are attempting to measure the stability of the pointing control system, and dithers may introduce confounding errors. **NOTE**: All observations must use the same guide star, and use just a single FGS (FGS1 is ideal) for guiding Jay Anderson is an expert in HST astrometry and the author of the HST1Pass software package. These tools will be used to measure the precise centroid of the stars in these images, as well as calculate any potential smearing of the PSF due to observatory drift (if present) 0 false false RESTRICTED STELLAR CLUSTER OPEN CLUSTER J2000 Timing link suitability includes constraints ([02 After 01 by 1.0 to 3.0 days]) The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. 1739245049000 72.7982016285558 (Tic-Visit :proposal-id 17893 :visit-id "01" :proposal-version -1 :trans-version "20241216" :date "19-Feb-2025 08:22:47.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. /Users/sbaggett/Downloads/OP-cache/17893-v51.xml (Tic-Visit :proposal-id 17893 :visit-id "51" :proposal-version -1 :trans-version "20241216" :date "21-Feb-2025 15:44:49.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "51" :obset-id "51" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "51" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([02 After 01 by 1.0 to 3.0 days] [03 After 02 by 1.0 to 3.0 days]) The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. 1739403653000 71.5542176275803 (Tic-Visit :proposal-id 17893 :visit-id "02" :proposal-version -1 :trans-version "20241216" :date "19-Feb-2025 08:22:49.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. /Users/sbaggett/Downloads/OP-cache/17893-v52.xml (Tic-Visit :proposal-id 17893 :visit-id "52" :proposal-version -1 :trans-version "20241216" :date "21-Feb-2025 15:44:51.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "52" :obset-id "52" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "52" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([03 After 02 by 1.0 to 3.0 days] [04 After 03 by 1.0 to 3.0 days]) The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. 1739494276000 70.84629866223739 (Tic-Visit :proposal-id 17893 :visit-id "03" :proposal-version -1 :trans-version "20241216" :date "19-Feb-2025 08:33:22.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([04 After 03 by 1.0 to 3.0 days] [05 After 04 by 1.0 to 3.0 days]) The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. 1739669079000 69.48837994726401 (Tic-Visit :proposal-id 17893 :visit-id "04" :proposal-version -1 :trans-version "20241216" :date "19-Feb-2025 08:33:28.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([05 After 04 by 1.0 to 3.0 days]) The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. 1739827462000 68.26080545375791 (Tic-Visit :proposal-id 17893 :visit-id "05" :proposal-version -1 :trans-version "20241216" :date "19-Feb-2025 08:33:31.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2300944 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17893 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17893 :visit-id "05" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2665 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 0