submission 2 1335139422 Assigned ID: 1761 ----- Attempting Submission 1 (Fri Apr 09 00:13:55 GMT 2021) ----- HST Phase I Proposal 1761 successfully submitted. Receipt: # 1761-1 ----- Attempting Submission 2 (Fri Apr 09 16:59:42 GMT 2021) ----- Changed to backup window for visit 1. -837747308 ----- Attempting Submission 1 (Sun Jul 25 15:26:49 GMT 2021) ----- ----- Attempting Submission 2 (Thu Jul 29 11:42:47 GMT 2021) ----- ----- Attempting Submission 3 (Wed Oct 20 12:56:09 GMT 2021) ----- ----- Attempting Submission 4 (Thu Nov 11 14:15:50 GMT 2021) ----- visit planner was run Constraining the Orbit of Eurybates' Satellite, Queta (3548) Eurybates will be the first Trojan asteroid to be explored in situ when the Lucy spacecraft flies by it in August 2027. The possibility of close-up study of Eurybates' satellite, Queta, offers a unique opportunity to test whether Eurybates' unusual properties are tied to its collisional history and, more broadly, how collisional evolution shapes small body populations. It is critical to reduce the orbital uncertainty and improve knowledge of the relative position of Queta as soon as possible to understand if there could be an impact to Lucy's encounter concept of operations and to optimize planning for the best angular resolution and lighting conditions in the brief window when observations can be made. By establishing a tighter constraint on the current orbit, it will be possible to accelerate searches for non-Keplerian motion should there be an additional satellite or satellites interior to Queta (as are commonly found in other collisional-family satellite systems). Additionally, we will use astrometric information from trailed stars in the full UVIS aperture to improve predictions for future stellar occultations. HST is required because Queta is 8.7 magnitudes fainter than Eurybates and will be observed at a separation of 0.5 arcsec - an observational regime that is unique to Hubble. This proposal is two orbits of astrometric observations of the satellite of Eurybates. It is intended to execute the orbits at known orbital phase to maximize the improvement in orbit determination needed to validate spacecraft pointing on approach. Each one - orbit visit will be identical 5 exposure sequence using the full WFC3 UVIS FOV to enable absolute astrometry with field stars as well as relative astrometry determined by measuring the positions of Eurybates and Queta. The proposal team has a combined many decades of experience observing with HST and publishing results. Most recently this team has published two papers detailing the discovery and orbit of Queta. This proposal extends that work and all of the needed tools are in place. Solar System Astronomy 6 false false false false false false false false SUPPORTED SOLAR SYSTEM ASTEROID Queta is a satellite of Eurybates TYPE=ASTEROID,A=5.194825660909952,E=0.08892019463262771,I=8.05897310596958 ,O=43.53959194136358,W=27.42986950746389,M=279.393486820639,EQUINOX=J2000,EPOCH=05-AUG-2019:00:00:00,EpochTimeScale=TDB EARTH WFC3/UVIS Imaging No No F350LP /private/var/folders/dd/hc9vrpdd56nfvg02_3n1tf5m0000gq/T/OPVisit17182499049459256783.xml Using ephemeris for target 16712-01-EURYBATES ephemeris data for target 16712-01-EURYBATES does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.213 to 23.089. ephemeris interval: 21.304 to 23.305 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16712 :visit-id "01" :proposal-version -1 :trans-version "20210514" :date "11-Nov-2021 09:11:21.0" :trans-errors '(:WARNINGS 0 :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 1443744 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16712 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16712 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2671 :al-overhead-at-end 0 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 1 0 Using ephemeris for target 16712-02-EURYBATES ephemeris data for target 16712-02-EURYBATES does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.213 to 23.089. ephemeris interval: 21.273 to 23.274 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16712 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "20-Oct-2021 08:53:21.0" :trans-errors '(:WARNINGS 0 :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 1443744 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16712 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16712 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2671 :al-overhead-at-end 0 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 1 0