0 Assigned ID: 966 ----- Attempting Submission 1 (Fri Apr 11 22:30:59 GMT 2014) ----- Submitted by Will Grundy on behalf of Marc Buie. Please keep me in the loop if there are issues with this program (w.grundy@lowell.edu). 508288691 ----- Attempting Submission 1 (Thu Jul 24 20:59:10 GMT 2014) ----- Deep Search for Small Satellites of Eris and Makemake Recent HST observations searching deeper than ever before have discovered a very distinct family of small, faint, circumbinary satellites around Pluto and Charon. Pluto has looked like the oddball of the Solar System many times in the past, with its inclined and eccentric transneptunian orbit, its enormous satellite Charon, and its volatile ice rich surface composition. But in each of these matters, subsequent discoveries revealed that Pluto was not unique, merely the first of an entirely new class of objects. This proposal aims to determine if Pluto's family of small faint satellites is also non-unique, through unprecedentedly deep imaging of Eris and Makemake, the two other most Pluto-like bodies in the Kuiper belt. We are observing (136199) Eris and (136472) Makemake looking for faint companions using observing procedures used successfully for the Pluto system. Our proposed observatations will improve on prior work in two fundamental ways. First, we plan a longer integration time that will get to a much fainter limiting magnitude. Each visit will take two orbits and we will take six ~730-sec exposures (three per orbit) and two short navigation images. A single visit stack nets an aggregate exposure time of ~4400 seconds and will yield an optimal SNR of 14 for an object of V=28 (assuming a G8V spectrum and average zodial light and background). This improvement will get us one magnitude deeper for Makemake and Eris. We will dither by small integer pixel amounts between images within a visit to help remove any potential detector artifacts. The second improvement comes from applying lessons learned while searching for faint satellites around Pluto. The biggest challenge to searching the inner regions is removing the confusion caused by the PSF of the primary and secondary objects (if present). The strategy used by Showalter and Buie was to take pairs of visits with controlled geometry. By design, Pluto and Charon were in the same relative position in raw pixel coordinates between the epochs and a difference of the two image stacks almost perfectly removes these two bright central objects. This technique led to the discovery of the fifth satellite around Pluto. That this new satellite is roughly V=27 attests to the sensitivity achieved. In the case of Pluto, the residual noise in the difference image is higher than any object on our list merely because the central object is not as bright. We can expect both changes to contribute to a much more thorough and deeper search than any done to date. Our basic observational pattern will use four orbits per object grouped into two visits with two orbits each. Each visit will lead to a deep stack and the pair will be used to search for a satellite that moves relative to the primary. A key component of the observing strategy is to maintain useful sensitivity to the motion of any putative satellites between the two visits. If the interval is too short there will not be enough time for detecting the motion though our technique would still reveal the presence of a satellite. Our survey is designed to cover out to 20% of the Hill radius. Larger distances are not expected to be stable. This threshold sets the minimum velocity that we have to accommodate. The time between visits is set to 2-3 days for Makemake and 3-4 days for Eris to ensure a minimum of 100 mas of satellite motion between visits at the outer edge of the stability region. We require a small roll between the two visits so that any object in the system will move relative to any PSF artifacts. This roll needs to be just a few degrees to facilitate the observations. Making the roll offset too large will make the observations difficult to schedule. These observations are specifically designed to find new satellites but will not, by themselves, do a very good job of determining orbits. It will remain for later work to followup any objects discovered. SOLAR SYSTEM 12 Regular false false false false false SUPPORTED SOLAR SYSTEM DWARF-PLANET Eris system STD=ERIS EARTH SOLAR SYSTEM DWARF-PLANET Makemake system STD=MAKEMAKE EARTH WFC3/UVIS Imaging No No F350LP WFC3/UVIS Imaging No No F350LP POS-TARG DITHER 0.290 This pattern is believed to be a half-pixel dithering pattern for purposes of sub-samping the image while being constructed to follow the distortion of the camera. The point spacing was multipled by 2 to make it an integer pixel pattern. This pattern is our ultimate goal so that a given target will fall in the same place relative to a unit pixel throughout all observations within a visit. LINE false false 3 46.84 WFC3-UVIS-DITHER-LINE 1 false Timing link suitability includes constraints ([02 After 01 by 3.0 to 4.0 days]) The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. Each visit is designed to collect a deep integration (two orbits per visit) on the target. For Eris, there are additional timing constraints. This constraint ensures that the observations of the known satellite, Dysnomia, will serve to break the mirror ambiguity on its current orbit. Without the timing constraint we would only have a 25% chance of getting the desired observation. Basically, the constraint serves to get this visit at a particular orbital longitude. The additional loose timing constraint restricts the observations to occur somewhat near opposition. This ensures a useful motion of the target relative to the background stars while also giving the best image scale and target brightness. 1422502483000 71.98890380899999 (Tic-Visit :proposal-id 13668 :visit-id "01" :proposal-version -1 :trans-version "20140605" :date "24-Jul-2014 13:57:27.0" :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 2309952 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13668 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13668 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2867 :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 3222 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13668 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2870 :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 3222 :pcs-gap 0 ) false 2 0 Timing link suitability includes constraints ([02 After 01 by 3.0 to 4.0 days]) The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. The second epoch is required to find a satellite moving relative to the primary object. The timing window is set to capture useful motion for an object at 20% of the Hill radius. Objects closer in will be moving faster. The relative roll is used to move the satellite system relative to the PSF between epochs. The minimal dithers are calculated for integer pixel shifts of the field (accounting for distortion) so that faint objects fall in the same place relative to a unit pixel in all images within a visit. 1422783291000 76.98890380900002 (Tic-Visit :proposal-id 13668 :visit-id "02" :proposal-version -1 :trans-version "20140605" :date "24-Jul-2014 13:57:30.0" :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 2309952 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13668 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13668 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2867 :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 3222 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13668 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2870 :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 3222 :pcs-gap 0 ) true 2 0 Timing link suitability includes constraints ([04 After 03 by 2.0 to 3.0 days]) The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. Each visit is designed to collect a deep integration (two orbits per visit) on the target. The loose timing constraint restricts the observations to occur somewhat near opposition. This ensures a useful motion of the target relative to the background stars while also giving the best image scale and target brightness. 1430141906000 141.0 (Tic-Visit :proposal-id 13668 :visit-id "03" :proposal-version -1 :trans-version "20150128" :date "27-Mar-2015 07:03:04.0" :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 2309952 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13668 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13668 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2820 :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 3222 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13668 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2823 :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 3222 :pcs-gap 0 ) false 2 0 Timing link suitability includes constraints ([04 After 03 by 2.0 to 3.0 days]) The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. The second epoch is required to find a satellite moving relative to the primary object. The timing window is set to capture useful motion for an object at 20% of the Hill radius. The relative roll is used to move the satellite system relative to the PSF between epochs. 1430336718000 147.0 (Tic-Visit :proposal-id 13668 :visit-id "04" :proposal-version -1 :trans-version "20150128" :date "27-Mar-2015 07:03:16.0" :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 2309952 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13668 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13668 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2820 :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 3222 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13668 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2823 :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 3222 :pcs-gap 0 ) false 2 0