0Assigned ID: 1204
----- Attempting Submission 1 (Fri Sep 25 21:48:10 GMT 2020) -----
----- Attempting Submission 2 (Wed Oct 07 13:56:25 GMT 2020) -----In this resubmission of this mid-cycle program I have updated the target orbital elements from JPL. I have adjusted the windows for visit 03 to avoid spoiler stars, and grouped it with visit 04 to merge our final 3 visits, allowing for gyro reset. -- Max Mutchler-1371034090----- Attempting Submission 1 (Mon Nov 09 21:06:10 GMT 2020) -----
Your proposal could not be saved.
Submission aborted.
----- Attempting Submission 2 (Wed Nov 11 19:06:43 GMT 2020) -----
----- Attempting Submission 3 (Sat Jun 05 15:36:36 GMT 2021) -----Active Asteroid P/2020 O1Exploratory observations of newly discovered active asteroid P/2020 O1 show evidence for protracted mass-loss and very low velocity ejection, consistent with prolonged sublimation of ice as the driving mechanism. We request mid-Cycle time in order to refine the analysis of P/2020 O1 using data from a variety of observational geometries, coupled with a sophisticated Monte Carlo dust dynamics model. Observations at high resolution and at a range of times and geometries are needed to definitively determine the mass loss mechanism. If water ice sublimation is confirmed, P/2020 O1 would be the icy asteroid with the smallest semimajor axis (highest temperature), setting new bounds on the distribution of ice in the asteroid belt.Our basic observing strategy is to take multiple long exposures (348 s) using WFC3 and a wide bandpass filter F350LP for maximum sensitivity. The F350LP filter provides a 1.6x higher count rate for a target with a solar-type spectrum, so we plan to use it. We also plan to dither the exposures to mitigate the effects from bad pixels, cosmic rays, and the inter-chip gap. The apparent rates of motion are easily within Hubbles tracking capabilities. These rates are also slow enough to keep a single pair of guide stars within the FGS pickles for an entire visibility window. The current 1-sigma ephemeris uncertainty of P/2020 O1 is about 4 arcsec and grows with time. However, we will improve the ephemeris iteratively, with each successive visit refining the orbit to get ready for the next. As a result, ephemeris errors will be negligible compared to the WFC3 field-of-view of 162 x 162 arcsec, so that ephemeris issues are of no concern to this observation. We understand that we may have essentially no control over the spacecraft roll angle, which means we will not be able to optimize the orientation of the dust tail on the CCD (i.e., to orient the tail along the longest dimension of the detector). However, the field-of-view of the camera is large enough that we should obtain excellent data on a portion of the tail, no matter what spacecraft roll angle is used. We request 5 orbits to characterize the progression of activity in P/2020 O1. The temporal distribution of the orbits is determined in part by the movement of the target into the 54 degree 4 Sun-exclusion zone of HST and in part by the changing heliocentric distance of the object. Visit 1 is one orbit as early as possible in late November/early December, to bridge the gap from the last observations in September. Visit 2 is one orbit late in 2020 December, close to the entry of P/2020 O1 into the Sun-exclusion zone on UT December 25. The heliocentric distance will be about 2.50 AU and the angle of the Earth above the orbital plane is near the maximum 1.9 degrees, providing the best perspective on the spatial distribution of dust and strong leverage for the dust dynamics models. Visit 3 is one orbit in 2021 July, as close as possible to the emergence of P/2020 O1 from the Sun-exclusion zone on UT 2021 July 6. The heliocentric distance is 2.75 AU and the angle from the orbit plane -1.6 degrees, again providing strong constraint on the dust models. Visit 4 is one orbit in 2021 August, about one month following Visit 3. Visit 5 is one orbit in 2021 September, about one month following Visit 4. With heliocentric distance 2.80 AU, we will sample the target similar to its 2.96 AU aphelion from an out-of-plane angle 0 degrees. Depending on the status of the activity, this is likely to provide our best constraint on the bare nucleus. Visits 1 and 2, together with existing ToO observations from September, will provide coverage of the dust development over 4 months following the 2020 May perihelion. If P/2020 O1 continues to be active in 2021, then Visits 3, 4 and 5 will extend the sampling of the activity for a full year. If activity should shut down before the summer, these visits will sample the evolution of the largest particles already ejected, expected to linger near the nucleus. These observations will provide powerful constraints on large particle ejection from P/2020 O1. Previously, large particles in comets have been studied mainly using thermal wavelengths, offering angular resolution 100 times poorer than HST. The dates of each visit are not critical at the level of a week to 10 days. The proposed scheduling will bridge the gap to observations to be proposed for Cycle 29.David Jewitt has a long record of study of the solar system's small body, primitive object populations, using HST and other telescopes. Max Mutchler is an expert in the optimum use of HST to study solar system targets. Hal Weaver is a ground- and space-based planetary astronomer with substantial expertise in the use of spacecraft data to study comets. Jing Li is experienced with the processing and photometry of astronomical data. Yoonyoung Kim and Jessica Agarwal are experts in the dynamics of comet dust under the action of solar gravity and radiation pressure. All are authors of numerous HST publications in the last 10 years.Solar System Astronomy3falsefalsefalsefalsefalsefalsefalsefalseSUPPORTEDSOLAR SYSTEMYESASTEROIDactive asteroidTYPE=COMET,Q=2.329339261954623,E=0.1198591438297583,I=5.22346273219021
,O=175.9889902558661,W=104.8273219832331,T=03-MAY-2020:18:25:03,TTimeScale=TDB,EQUINOX=J2000,EPOCH=28-JUL-2020:00:00:00,EpochTimeScale=TDBEARTHSOLAR SYSTEMYESASTEROIDactive asteroidTYPE=COMET,Q=2.329334434263673,E=0.1198571503419016,I=5.223476693804598
,O=175.9886843766403,W=104.827482351413,T=03-MAY-2020:18:24:37,TTimeScale=TDB,EQUINOX=J2000,EPOCH=29-JUL-2020:00:00:00,EpochTimeScale=TDBEARTHWFC3/UVISImagingNoNoF350LPPOS-TARGDITHER0.145LINEfalsefalse246.84WFC3-UVIS-DITHER-LINE1falseUsing ephemeris for target 16463-01-P2020-O1ephemeris data for target 16463-01-P2020-O1 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 20.299 to 22.152. ephemeris interval: 21.151 to 23.152The scheduling data was generated by CASM 29.0.CASM was run in Phase II mode.160628434700072.25581710042371(Tic-Visit
:proposal-id 16463
:visit-id "01"
:proposal-version -1
:trans-version "20200619"
:date "05-Jun-2021 11:02:03.0"
: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 422320
:tdrss-contact-duration 0
:coron NIL
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(Tic-Obset
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:visit-id "01"
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(Tic-Orbit
:proposal-id 16463
:visit-id "01"
:orbit-number 1
:pcs-time 393
:si-vis-utilization 2698
:al-overhead-at-end 0
:internal-dur-at-end 498
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3142
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)true10Using ephemeris for target 16463-02-P2020-O1ephemeris data for target 16463-02-P2020-O1 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 20.299 to 22.152. ephemeris interval: 21.151 to 23.152The scheduling data was generated by CASM 29.0.CASM was run in Phase II mode.160888125100069.3428448442373(Tic-Visit
:proposal-id 16463
:visit-id "02"
:proposal-version -1
:trans-version "20200619"
:date "05-Jun-2021 11:02:05.0"
: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 422320
:tdrss-contact-duration 0
:coron NIL
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(Tic-Obset
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(Tic-Orbit
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:visit-id "02"
:orbit-number 1
:pcs-time 393
:si-vis-utilization 2698
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:internal-dur-at-end 498
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3142
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)true10Using ephemeris for target 16463-03-P2020-O1-V3ephemeris data for target 16463-03-P2020-O1-V3 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 20.299 to 22.152. ephemeris interval: 21.151 to 23.152Timing link suitability includes constraints ([Group (03 04) Within 0.1 days])The scheduling data was generated by CASM 29.0.CASM was run in Phase II mode./System/Volumes/Data/solaris/user1/sherwin/16463/OP-cache/16463-v03.xml(Tic-Visit
:proposal-id 16463
:visit-id "03"
:proposal-version -1
:trans-version "20200619"
:date "08-Jun-2021 11:07:05.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 2
:saa-model "29"
:si-bright-earth-limb-angle 20.0
:data-volume 844656
:tdrss-contact-duration 0
:coron NIL
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(Tic-Obset
:proposal-id 16463
:visit-id "03"
:obset-id "03"
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(Tic-Orbit
:proposal-id 16463
:visit-id "03"
:orbit-number 1
:pcs-time 393
:si-vis-utilization 2518
:al-overhead-at-end 0
:internal-dur-at-end 0
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3142
:pcs-gap 0
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(Tic-Orbit
:proposal-id 16463
:visit-id "03"
:orbit-number 2
:pcs-time 392
:si-vis-utilization 2486
:al-overhead-at-end 0
:internal-dur-at-end 652
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3142
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)true20Using ephemeris for target 16463-04-P2020-O1-V3ephemeris data for target 16463-04-P2020-O1-V3 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 20.299 to 22.152. ephemeris interval: 21.151 to 23.152Timing link suitability includes constraints ([Group (03 04) Within 0.1 days])The scheduling data was generated by CASM 29.0.CASM was run in Phase II mode./System/Volumes/Data/solaris/user1/sherwin/16463/OP-cache/16463-v04.xml(Tic-Visit
:proposal-id 16463
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:proposal-version -1
:trans-version "20200619"
:date "08-Jun-2021 11:07:07.0"
: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 422320
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
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:visit-id "04"
:obset-id "04"
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(Tic-Orbit
:proposal-id 16463
:visit-id "04"
:orbit-number 1
:pcs-time 393
:si-vis-utilization 2518
:al-overhead-at-end 0
:internal-dur-at-end 498
:dark-offset NIL
:dark-utilization 0
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:low-sky "N"
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