0 Assigned ID: 3955 ----- Attempting Submission 1 (Thu May 18 19:42:35 GMT 2023) ----- HST Phase I Proposal 3955 successfully submitted. Receipt: # 3955-1 The list of Investigators does not match the STScI records for this program. rev1, JYL, 2023-06-08 Extend between window to June 26 -- July 7 for all visits. 2/13/2024, JYL - Add Co-I Bin Yang. -2126534861 ----- Attempting Submission 1 (Thu Jun 08 13:23:15 GMT 2023) ----- ----- Attempting Submission 2 (Thu Jun 08 15:57:47 GMT 2023) ----- ----- Attempting Submission 3 (Tue Feb 13 02:00:59 GMT 2024) ----- This submission is to add Co-I Bin Yang. Deep Imaging of Dimorphos's Dust Tail We request 10 DD orbits to perform deep imaging of the tail of Dimorphos created by the DART impact in early July before the Didymos system moves into the solar avoidance zone and remains unobservable for ~7 months. The proposed program continues the previous HST programs GO-16674 and GO-17292 to study the formation and evolution of the dust tail formed from the impact ejecta. The proposed observations will allow us to study the evolution of the brightness profile of the tail and the diffuse dust feature to the south of the main tail noticed in February image. Preliminary evidence suggests that the diffuse cloud contains particles lifted by the re-impact of large DART ejecta particles. In the context of the data collected by other post-impact HST programs to observe Didymos, we will constrain the size, size distribution, total mass, and dust dynamics of the ejecta in the binary system, and will explore the mechanisms of delayed dust emission from the binary system. As the first active asteroid with precisely known impact conditions and much better determined physical properties than any other active asteroids, these studies will form the foundation for us to improve our understanding of past and future active asteroid observations, and therefore have broad implications for active asteroid research. The high spatial resolution and sensitivity of HST/WFC3/UVIS are essential for the proposed observations. These observations could not be proposed during the regular Cycle 30 proposal period because we could not have predicted the brightness of teh tail before impact. The tail continues to evolve and fade and so the proposed observations cannot wait until Cycle 31. We plan to observe the tail of Dimorphos in the week between June 30, 2023 and July 6, 2023, right before the Didymos system moves to within the solar avoidance zone. If it's difficult to schedule within this week, we can extend the window to two weeks without affecting the science objectives. The ten orbits do not need to be consecutive, but should be placed as close to each other as possible, e.g., to allow all orbits to be executed within 2 days, to facilitate the stack of all images. All orbits will have the same structure. In each orbit, we will use F350LP filter to take four exposures of 450s each, using the full-frame aperture UVIS2-FIX. The large geocentric distance of 2.5 au of the target allows for the long exposure time without trailing due to parallax. The use of full-frame aperture will allow us to capture the tail as much as possible. In fact, 2k-by-2k subframe will cause more overhead time. The long exposures will hide the buffer dump behind the exposures. The tail of Dimorphos is expected to extend at a position angle about 295 deg during our observing window. The roll angle range of HST during our observing window is 105 - 115 deg, allowing the tail to extend along the diagnal direction of the full-frame CCD field of view. There is no need to impose orientation requirements. We will offset the target in the opposition direction of the tail by 40" to allow for more space for the tail. We will also use a two point dither pattern in each orbit with (1", -2") offset in x and y directions to avoid bad pixels/columns and the chip gap. The proposal team is similar to the teams of the previous HST program GO-16674 to observe the Dimorphos's ejecta during the DART impact, as well as HST program GO-17292 to monitor the long-term evolution of the tail. A few new Co-Is are added for their various expertise areas that are useful for this program. The team has extensive experience with HST observations, a strong association with the DART Investigation Team, and expertise in studying active asteroids, dust brightness and optical depth measurements and modeling, and ejecta and tail dynamic modeling. These expertise areas cover all the required aspects to perform the proposed observations and to analyze the data. PI Jian-Yang Li (Planet. Sci. Inst.) is the PI of the highly successful HST DART ejecta observing program GO-16674, and the PI of the long-term tail monitoring program GO-17292. He is a highly experienced HST observer who has led or been involved in many HST imaging and spectroscopic programs for asteroids and comets over the past 15 years, including a number of time-critical ones that required close coordination with the STScI during the scheduling and execution. He has also been involved in many observations and data analysis of cometary comae, including the Deep Impact mission that impacted comet 9P/Tempel 1. Co-Is Andy Cheng (JHU/APL) and Andy Rivkin (JHU/APL) are the DART mission team co-leads and have profound knowledge about all aspects of the mission. In addition, Rivkin's research has focused on asteroid observations since the 1990s. Co-I Cristina Thomas (N. Arizona U.) is the DART Observations Working Group Lead who oversees all aspects of the coordinated observing campaign to support the DART mission. She was the PI of HST UV spectral observations of Jupiter Trojan asteroids that are targets of the upcoming Lucy mission. Co-I Eugene Fahnestock (Caltech/JPL) is the DART Ejecta Working Group Lead and an expert on impact ejecta dynamic simulation and modeling. Co-I Harold Weaver is a veteran of HST imaging and spectroscopy observer and has been extensively involved in many previous HST observations of active asteroids, including P/2010 A2, Scheila, 311P/PanSTARRS, and Gault. Co-I Matthew Knight (U.S. Naval Academy) is an expert on observing and interpreting cometary coma morphology from ground-based telescopes and HST. Co-I Steven Chesley is an expert on the dynamic modeling of asteroids, comets, and dust. Co-I Ludmilla Kolokolova (U. Maryland) is an expert on the modeling of the optical properties of dust from observational data, including HST images, and a DART Participating Scientist who will model the DART ejecta from both the LICIACube images and HST images of ejecta, based on her similar work on the Deep Impact ejecta. Co-I Masatoshi Hirabayashi (Auburn U.) has expertise in quantifying the mechanisms for mass ejection from active asteroids and ejecta evolution. He has also developed finite element models to characterize the thermal condition of an irregularly shaped body to determine solar radiation pressure-driven non-gravitational forces. Co-I Yun Zhang (U. Maryland) is experienced in dust dynamics and the internal structures of asteroids through numerical models. Co-I Tony Farnham (U. Maryland) is an expert in observing comets and analyzing the cometary dust images. Co-I Fernando Moreno (Instituto de Astrofisica de Andalucia, CSIC, Spain) is experienced in Monte Carlo modeling of comets and active asteroids dust tails. Co-I Gonzalo Tancredi (Depto. Astrononia, Fac. Ciencias, Udelar, Uruguay) is experienced in the mechanisms for mass ejections associated with impact processes and modeling the formation of tails, as well as comparison with other active asteroids. Solar System Astronomy 0 false SUPPORTED SOLAR SYSTEM YES ASTEROID Binary asteroid (65803) Didymos TYPE=ASTEROID,A=1.642514363757057,E=0.3832947329867846,I=3.414168800300961 ,O=72.99221760945375,W=319.5559920731379,M=38.72558818260499,EQUINOX=J2000,EPOCH=12-JAN-2023:12:00:00,EpochTimeScale=TDB,R0=1. ,A1=0.,A2=-1.042309691002E-14,A3=0. ,ALN=1.,NM=2.,NN=0.,NK=0.,AMRAT=0. EARTH WFC3/UVIS Imaging No No F350LP Using ephemeris for target 17330-01-DIDYMOS ephemeris data for target 17330-01-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688102139000 109.61021371687912 (Tic-Visit :proposal-id 17330 :visit-id "01" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:17.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-02-DIDYMOS ephemeris data for target 17330-02-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688107844000 109.61593992901021 (Tic-Visit :proposal-id 17330 :visit-id "02" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:18.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-03-DIDYMOS ephemeris data for target 17330-03-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688113548000 109.62165924279071 (Tic-Visit :proposal-id 17330 :visit-id "03" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:18.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "03" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-04-DIDYMOS ephemeris data for target 17330-04-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688119347000 108.29635842428138 (Tic-Visit :proposal-id 17330 :visit-id "04" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:19.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "04" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) false 1 0 Using ephemeris for target 17330-05-DIDYMOS ephemeris data for target 17330-05-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688187708000 115.0 (Tic-Visit :proposal-id 17330 :visit-id "05" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:19.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "05" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-06-DIDYMOS ephemeris data for target 17330-06-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688193412000 115.0 (Tic-Visit :proposal-id 17330 :visit-id "06" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:20.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "06" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-07-DIDYMOS ephemeris data for target 17330-07-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688199117000 115.0 (Tic-Visit :proposal-id 17330 :visit-id "07" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:21.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "07" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-08-DIDYMOS ephemeris data for target 17330-08-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688604123000 110.28620229158793 (Tic-Visit :proposal-id 17330 :visit-id "08" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:21.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "08" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-09-DIDYMOS ephemeris data for target 17330-09-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688609827000 110.28835156648051 (Tic-Visit :proposal-id 17330 :visit-id "09" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:22.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "09" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0 Using ephemeris for target 17330-10-DIDYMOS ephemeris data for target 17330-10-DIDYMOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 22.213 to 24.182. ephemeris interval: 23.151 to 25.152 The scheduling data was generated by CASM 31.0. CASM was run in Phase II mode. 1688615531000 110.29049482800212 (Tic-Visit :proposal-id 17330 :visit-id "10" :proposal-version -1 :trans-version "20220630" :date "08-Jun-2023 11:53:22.0" :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 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17330 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17330 :visit-id "10" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2388 :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 2782 :pcs-gap 0 ) true 1 0