0 Assigned ID: 1932 ----- Attempting Submission 1 (Fri Apr 09 14:34:30 GMT 2021) ----- 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 Added new visit v2rep, as the repeat of failed visit 2 (HOPR 92361). These visits are BETWEENs to avoid bright background objects, covering the time span 19-Dec-2022 to 08-Jan-2023. A new target 288-B has been defined for v2rep, which is the same asteroid but reflects the updated JPL orbit solution as compared to visits 1 and 2. 646384009 Your proposal could not be saved. Submission aborted. Your proposal could not be saved. Submission aborted. ----- Attempting Submission 1 (Fri Jul 23 07:56:45 GMT 2021) ----- ----- Attempting Submission 2 (Thu Jul 21 21:04:54 GMT 2022) ----- ----- Attempting Submission 3 (Wed Jul 27 07:03:50 GMT 2022) ----- ----- Attempting Submission 4 (Fri Sep 02 10:18:59 GMT 2022) ----- ----- Attempting Submission 6 (Tue Nov 01 15:26:51 GMT 2022) ----- The flash warning disappears when the ETC is run for actual zodiacal light conditions at the time of observation (WFC3UVIS.im.1526789). Interconnection between outgassing, fast rotation and mutual orbit in binary main-belt comet 288P The binary asteroid 288P is unusual both for its sublimation-driven activity and for its peculiar mutual orbit combining similarly-sized components with a wide separation and high eccentricity. The second half if 2022 will witness the 288P system emerging from its second perihelion passage after the binary nature was discovered. We here seek to verify the possibility indicated by earlier HST observations that the mutual orbit was perturbed by an outgassing-induced torque during the 2016/17 perihelion passage. If confirmed, the activity could have led to the unusually wide semimajor axis that cannot be achieved directly from rotational fission. In addition we seek to consolidate the identity of the active component(s) to find out if the activity is a direct consequence of the splitting event leading to binary formation. We also aim to constrain the size of the largest dust particles emitted from the active component(s) that is diagnostic of the strength of sublimation and the potential role played by fast rotation in lifting the dust. Finally, we seek to understand whether the level of activity is constant between apparitions, or if a trend can be identified that would indicate the evolution of exposed ice on main belt asteroids with time. We request five orbits of HST/WFC3 time to be scheduled at roughly 4 week intervals between August and December 2022. These data will allow us to measure the brightness and separations of the components and the evolution of dust lingering from the perihelion passage in winter 2021/22. Only HST is able to spatially resolve the components (max. separation 0.1 arcsec) and central dust cloud of this faint (V=22mag) target. The purpose of this proposal is to observe how activity decreases and ends as the binary main-belt comet 288P moves out from perihelion in the second half of 2022. We plan to observe 288P in 4-weeks intervals between mid-August and early December. Hence two of these 1-orbit visits fall into Cycle 29 and three into Cycle 30. This phase 2 proposal is for the two Cycle 29 visits only. The visits should be carried out around 2022 August-13 and September-10, with a flexibility of 1 week. We expect a target brightness of V=22.5 mag, depending on time. In each orbit, we will take 8 exposures of 239s 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 1912 s = 32 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. The target will be at solar elongations between 70 and 90deg. 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 and will carry out the dust dynamical modelling, 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 SUPPORTED SOLAR SYSTEM YES ASTEROID Binary main-belt comet TYPE=ASTEROID,A=3.048986186274839,E=0.2010716723979907,I=3.240152574320395 ,O=83.18716341122048,W=281.0201183529284,M=37.18809486522964,EQUINOX=J2000,EPOCH=28-MAY-2017:00:00:00,EpochTimeScale=TDB EARTH SOLAR SYSTEM YES ASTEROID Binary main-belt comet TYPE=ASTEROID,A=3.048895795723726,E=0.2010747670269393,I=3.240200267468515 ,O=83.18689950470417,W=281.0089661495639,M=50.34116073331901,EQUINOX=J2000,EPOCH=07-AUG-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 POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 1 false Using ephemeris for target 16687-01-288P ephemeris data for target 16687-01-288P does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.191 to 23.305. ephemeris interval: 22.304 to 24.306 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. /tmp/OPVisit15346330609617704227.xml BETWEENs will be used to avoid times when 288P should not be observed due to the proximity of bright background stars. These need to be updated once the HST orbit for this epoch is known in the JPL/Horizons system. 1660102280000 258.4586251461851 (Tic-Visit :proposal-id 16687 :visit-id "01" :proposal-version -1 :trans-version "20220630" :date "01-Nov-2022 16:22:50.0" :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 16687 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16687 :visit-id "01" :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 When running the ETC for the actual zodiacal light background on Sep-01 (used as reference date for both visits), the flash warning disappears (ETC Request ID: WFC3UVIS.im.1526789). Using ephemeris for target 16687-02-288P ephemeris data for target 16687-02-288P does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.191 to 23.305. ephemeris interval: 22.304 to 24.306 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. /tmp/OPVisit9261496619061791193.xml BETWEENs will be used to avoid times when 288P should not be observed due to the proximity of bright background stars. These need to be updated once the HST orbit for this epoch is known in the JPL/Horizons system. 1663868339000 263.74498254458257 (Tic-Visit :proposal-id 16687 :visit-id "02" :proposal-version -1 :trans-version "20220630" :date "01-Nov-2022 16:22:53.0" :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 16687 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16687 :visit-id "02" :orbit-number 1 :pcs-time 301 :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 When running the ETC for the actual zodiacal light background on Sep-01 (used as reference date for both visits), the flash warning disappears (ETC Request ID: WFC3UVIS.im.1526789). Using ephemeris for target 16687-03-288P-B ephemeris data for target 16687-03-288P-B does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.191 to 23.305. ephemeris interval: 22.304 to 24.306 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. /tmp/OPVisit10378161800260103943.xml This visit is intended as the repeat of failed visit 2. A new target 288P-B has been defined and used for this visit. This target is the same asteroid (288P), but reflects the updated JPL orbit solution. BETWEENs to avoid bright background targets cover three weeks in late December 2022 and early January 2023. (Tic-Visit :proposal-id 16687 :visit-id "03" :proposal-version -1 :trans-version "20220630" :date "01-Nov-2022 16:22:56.0" :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 16687 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16687 :visit-id "03" :orbit-number 1 :pcs-time 301 :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 When running the ETC for the actual zodiacal light background on Sep-01 (used as reference date for both visits), the flash warning disappears (ETC Request ID: WFC3UVIS.im.1526789).