mid-cycle 28 -1323376219 Assigned ID: 1209 ----- Attempting Submission 1 (Tue Sep 29 20:27:21 GMT 2020) ----- HST Phase I Proposal 1209 successfully submitted. Receipt: # 1209-1 Added additional windows for repeat visit. Increased exposure time by 50% to account for decreased brightness. 499803510 ----- Attempting Submission 1 (Fri Nov 13 18:14:44 GMT 2020) ----- ----- Attempting Submission 2 (Fri Dec 04 22:24:31 GMT 2020) ----- ran visit planner. Is the Lucy Mission Target (52246) Donaldjohanson a Binary? (52246) Donaldjohanson is a Main Belt asteroid target of opportunity that the Lucy mission will fly by in April 2025. In August 2020 it was revealed to have an exceptionally high amplitude and long period lightcurve. We propose here to test the possibility that this extreme lightcurve is produced by a synchronous binary. Such a system can explain both the amplitude and period with physically reasonable component shapes. The observations will take advantage of the only opportunity prior to 2025 when such a binary could be resolved by HST during the unusually close perihelic opposition in December 2020. The identification of a binary impacts the choice of target acquisition software to be used by the Lucy spacecraft during flyby. Single orbit visit of asteroid (52246) Donaldjohanson in Nov-Dec 2020 when it is less than 1.08 AU from Earth. 9 dithered exposures in each of the F438W and F555W filters. The proposal team has extensive experience using HST and a strong record of publication. Solar System Astronomy 6 false false false false false false false SUPPORTED SOLAR SYSTEM ASTEROID Main Belt TYPE=ASTEROID,A=2.383408217708659,E=0.1869719367322857,I=4.423713412634814 ,O=262.8234180381248,W=213.1874689016715,M=197.7867423053335,EQUINOX=J2000,EPOCH=05-AUG-2019:00:00:00,EpochTimeScale=TDB EARTH WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F555W Using ephemeris for target 16452-01-DONALDJOHANSON ephemeris data for target 16452-01-DONALDJOHANSON does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 20.214 to 22.089. ephemeris interval: 20.305 to 22.305 The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. 1606989540000 122.35748644317181 (Tic-Visit :proposal-id 16452 :visit-id "01" :proposal-version -1 :trans-version "20200619" :date "13-Nov-2020 12:27:41.0" :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 82384 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16452 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16452 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2297 :al-overhead-at-end 0 :internal-dur-at-end 127 :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 16452-51-DONALDJOHANSON ephemeris data for target 16452-51-DONALDJOHANSON does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 20.308 to 22.089. ephemeris interval: 20.335 to 22.335 The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. /private/var/folders/dd/hc9vrpdd56nfvg02_3n1tf5m0000gq/T/OPVisit9586147744957166997.xml (Tic-Visit :proposal-id 16452 :visit-id "51" :proposal-version -1 :trans-version "20200619" :date "04-Dec-2020 17:22:10.0" :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 82384 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16452 :visit-id "51" :obset-id "51" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16452 :visit-id "51" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2567 :al-overhead-at-end 0 :internal-dur-at-end 127 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 1 0