Re-activation of binary main-belt comet 288P

0 Assigned ID: 745 ----- Attempting Submission 1 (Fri Mar 06 20:29:55 GMT 2020) ----- HST Phase I Proposal 745 successfully submitted. Receipt: # 745-1 ----- Attempting Submission 2 (Fri Mar 06 21:40:02 GMT 2020) ----- ORBITAL VISIBILITY OVERRUN FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser Created target 3 with updated ephemeris. Linked visit 52 with this new target 3, and added betweens for visit 52 designed to avoid bright stars near the asteroid. The betweens now cover the first three weeks of November. If needed, I'll add betweens also out to mid-December. 1885068449 ----- Attempting Submission 1 (Tue Jun 16 16:22:11 GMT 2020) ----- Your proposal could not be saved. Submission aborted. Your proposal could not be saved. Submission aborted. ----- Attempting Submission 2 (Wed May 05 11:30:47 GMT 2021) ----- ----- Attempting Submission 3 (Sat May 15 16:32:22 GMT 2021) ----- ----- Attempting Submission 4 (Mon Aug 09 14:31:13 GMT 2021) ----- HST Phase II Proposal 16192 failed submission. ----- Attempting Submission 5 (Mon Aug 09 14:35:57 GMT 2021) ----- ----- Attempting Submission 6 (Fri Aug 13 06:41:27 GMT 2021) ----- ----- Attempting Submission 7 (Tue Oct 12 15:53:18 GMT 2021) ----- If running the WFC3 ETC with the actual zodiacal light background for late September 2021, the calculated background is 19 electrons per pixel (ETC run WFC3UVIS.im.1532041), so the flash warning in APT would disappear. The visibility overrun for visit 1 is irrelevant because visit 1 has already been executed. Re-activation of binary main-belt comet 288P We propose to closely follow the expected re-activation of the unusual binary main-belt comet 288P (300163) in the fall of 2021, to identify the active component(s). This is a crucial parameter to understand the formation and evolution of this system which is unique among the known binary asteroids both because of its comet-like activity and because of its wide, eccentric and asynchronous mutual orbit in combination with similarly sized components. We request a total of 8 orbits. Seven orbits, distributed across one month, will serve to measure the brightness increase due to dust as the system re-approaches perihelion in 2021. In addition, we request 1 orbit in 2021 June to probe for a potential orbit instability. It is currently unclear why no other systems with similar orbital properties as 288P are known. There is a strong detection bias against such systems, and the binary nature of 288P was only identified because of its activity. One the other hand, if activity is needed to form such systems, they may indeed be rare. Our proposed observations will shed light on the frequency of similar systems and on the processes behind binary asteroid formation and evolution. Since the re-activation is expected for the 2021 September-October time frame, we request 4 orbits in Cycle 28 and 4 orbits in Cycle 29. The purpose of the proposed observations is to monitor the re-activitation of the binary main-belt comet 288P that is expected to take place in September/October 2021. We will use 1 orbit of WFC3 imaging in 2021 June to establish the orbital state of the system and verify its predicted binary orbit and rotation state. This will be followed by 3 orbits of WFC3 imaging in 2021 September, and 4 additional orbits in October, that have been allocated for Cycle 29. The current phase 2 proposal covers only the 4 orbits in Cycle 28. The three September visits should be carried out on Sep-20, 25, and 30, with +/- 1 day flexibility. This timing is crucial to -) catch the expected time interval of re-activation (2021 mid-September to mid-October) -) follow the growth of the dust coma, which is expected to take place on timescales of several days -) catch the system at maximum separation (2021 September) The orbital visibility for a solar system target near the ecliptic plane is 54 min (Section 6.3 of the HST Primer document). In each orbit, we will take 8 exposures of 280s using the C512C subarray of WFC3 and perform a 2-point dither pattern to mitigate hot pixels and cosmic ray hits, obtaining 4 exposures at each dither point. This provides a total exposure time of 2240 s = 37 min. The ephemeris is known with uncertainty <1arcsec, such that there is no risk of missing the target even using the C512C sub-array. We will use the wide bandpass filter F606W for an optimum trade-off between sensitivity and highest resolution, and maximum compatibility with data from earlier epochs. We expect a target brightness of V=22-23 mag, depending on time. Should the program have to be carried out in 1gyro mode we can shorten the exposure time to adapt to the increased time for guide star acquisition. The target will be at solar elongations >100deg, hence the enlarged solar exclusion zone will not pose a problem. Jessica Agarwal previously analyzed HST data on active asteroids to place constraints on the dust ejection process from the dust dynamics and photometry. She is the PI of several HST programs that lead to the discovery and further analysis of the unusual binary main-belt comet 288P. She will carry out the PSF fitting to measure the component separations and brightnesses, and fit the orbit. Yoonyoung Kim is an expert in the dynamical modeling of dust moving under the action of gravity, solar radiation pressure and initial velocity distribution. David Jewitt has an extensive record of research into the study of small solar system bodies, especially the Kuiper belt objects and the cometary nuclei. In the last decade he has written >20 refereed papers based on Hubble data. He will contribute to the measurement, analysis and interpretation of the data and to writing up the results for publication. Max Mutchler is an expert on Hubble's cameras. He will contribute to the subsampling observing strategy, and special image processing for moving targets. Harold Weaver is a veteran Hubble observer, mostly of comets, with many Hubble-related publications. He will contribute to optimizing the observation strategy and to interpreting the data. Stephen Larson is an experienced investigator of small Solar system bodies and the PI of the Catalina Sky Survey, from which previous HST targets including the outburst of (596) Scheila, P/2013 R3 and 313P were discovered. He will contribute to the data interpretation. Solar System Astronomy 6 false false false false false false false false SUPPORTED SOLAR SYSTEM NO ASTEROID binary main-belt comet TYPE=ASTEROID,A=3.048393453467953,E=0.2010255843911559,I=3.240298141902801 ,O=83.19481820313729,W=281.1289229646505,M=287.3130186959124,EQUINOX=J2000,EPOCH=13-OCT-2015:00:00:00,EpochTimeScale=TDB EARTH SOLAR SYSTEM NO ASTEROID Active Asteroid TYPE=ASTEROID,A=3.049068871630956,E=0.2010668788752906,I=3.240047909880679 ,O=83.19202143297311,W=281.0719211810388,M=333.0984342006854,EQUINOX=J2000,EPOCH=16-JUN-2016:00:00:00,EpochTimeScale=TDB EARTH SOLAR SYSTEM NO ASTEROID Active Asteroid TYPE=ASTEROID,A=3.048983417833043,E=0.2010721219292816,I=3.240155687537047 ,O=83.18714325056506,W=281.0196226634146,M=37.74383008099473,EQUINOX=J2000,EPOCH=31-MAY-2017:00:00:00,EpochTimeScale=TDB EARTH WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 1

false

1634053644252 Using ephemeris for target 16192-01-288P ephemeris data for target 16192-01-288P does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.128 to 22.274. ephemeris interval: 21.273 to 23.274 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. BETWEENs are used to avoid times when 288P should not be observed due to the proximity of bright background stars. 1623121373000 255.56459084479673 (Tic-Visit :proposal-id 16192 :visit-id "01" :proposal-version -1 :trans-version "20210514" :date "12-Oct-2021 17:47:24.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16192 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16192 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2716 :al-overhead-at-end 0 :internal-dur-at-end 77 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2782 :pcs-gap 0 ) true 1 1 1634053646977 Using ephemeris for target 16192-02-288P2 ephemeris data for target 16192-02-288P2 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.128 to 22.274. ephemeris interval: 21.273 to 23.274 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. 1632059603000 80.7234677952066 (Tic-Visit :proposal-id 16192 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "12-Oct-2021 17:47:26.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16192 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16192 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :al-overhead-at-end 0 :internal-dur-at-end 77 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2782 :pcs-gap 0 ) true 1 0 1634053639384 Using ephemeris for target 16192-52-288P3 ephemeris data for target 16192-52-288P3 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.128 to 22.274. ephemeris interval: 21.273 to 23.274 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. HOPR repeat of visit 52. (Tic-Visit :proposal-id 16192 :visit-id "52" :proposal-version -1 :trans-version "20210514" :date "12-Oct-2021 17:47:19.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16192 :visit-id "52" :obset-id "52" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16192 :visit-id "52" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :al-overhead-at-end 0 :internal-dur-at-end 77 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2782 :pcs-gap 0 ) true 1 0 1634053650112 Using ephemeris for target 16192-03-288P2 ephemeris data for target 16192-03-288P2 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.128 to 22.274. ephemeris interval: 21.273 to 23.274 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. 1632471342000 72.86541804787231 (Tic-Visit :proposal-id 16192 :visit-id "03" :proposal-version -1 :trans-version "20210514" :date "12-Oct-2021 17:47:29.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16192 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16192 :visit-id "03" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :al-overhead-at-end 0 :internal-dur-at-end 77 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2782 :pcs-gap 0 ) true 1 0 1634053653041 Using ephemeris for target 16192-04-288P2 ephemeris data for target 16192-04-288P2 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 21.128 to 22.274. ephemeris interval: 21.273 to 23.274 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. 1633025938000 75.9588964286373 (Tic-Visit :proposal-id 16192 :visit-id "04" :proposal-version -1 :trans-version "20210514" :date "12-Oct-2021 17:47:32.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16192 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16192 :visit-id "04" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :al-overhead-at-end 0 :internal-dur-at-end 77 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2782 :pcs-gap 0 ) true 1 0