adjusted link on visit 7 to go one orbit earlier than before.----- Attempting Submission 1 (Mon Aug 29 15:28:58 GMT 2011) -----
----- Attempting Submission 2 (Mon Aug 29 20:20:09 GMT 2011) -----
----- Attempting Submission 3 (Wed Aug 31 13:18:42 GMT 2011) -----
HST Phase II Proposal 12725 (12725.apt) successfully submitted.
----- Attempting Submission 4 (Wed Aug 31 13:27:44 GMT 2011) -----
----- Attempting Submission 5 (Thu Sep 01 17:29:41 GMT 2011) -----A Deep Search for Satellites in the Pluto System: Providing Critical, Safety-of-Flight Support to NASA's New Horizons MissionWe propose a simple, 9-orbit (3 orbits at each of 3 epochs) DD program
with two objectives: (1) as a safety-of-flight issue, perform a deep
search (V=25-26) for satellites in the 0.9 arcsec radius region between
Pluto and Charon where NASA's New Horizons mission will fly, and (2)
confirm or reject the candidate P5 and P6 satellites seen in recent HST
imaging, while performing an even deeper search (V=27) for satellites in
the region between Charon and Hydra so observations of them can be
planned before the New Horizons mission planning is frozen prior to the
on-spacecraft rehearsal. Hubble is uniquely qualified to achieve these
time-critical objectives, which we hope to achieve before the Pluto system
enters the Hubble solar exclusion zone in early November.Our program has two principal measurement objectives: (1) search for faint satellites within ~0.4" of Pluto,
which defines the outer edge of one of the orbital stability zones, and (2) search for even fainter satellites farther out,
particularly in the regions near P5 and P6.
Unfortunately, these different objectives require different observing strategies.
We must take many (32) relatively short exposures (30s) to search for satellites within Charon’s orbit,
going deep but preventing saturation in the region of interest. To achieve maximum sensitivity for the
deep search outside Charon’s orbit, we use longer exposures (175s) and take fewer images (12) to minimize overhead.
After running multiple sensitivity calculations with the WFC3 ETC (see below) and determining how best to
pack the images into a Hubble orbit using APT, we have selected the following 3-orbit plan for each epoch of
observations (all images employ the WFC3 with the F350LP filter; the measurement objectives are given in parentheses):
Orbit #1:
-Take one 3s image (providing unsaturated images of Pluto and Charon for astrometry)
-Take 16 x 30s images (deep search for faint satellites within Charon’s orbit)
-Take 16 x 30s images at a dithered location (5 pixels offset in both x and y)
Orbit #2:
-Take one 3s image (providing unsaturated images of Pluto and Charon for astrometry)
-Take 6 x 175s images (deep search for faint satellites outside of Charon’s orbit)
-Take 6 x 175s images at a dithered location (5 pixels offset in both x and y)
Orbit #3:
-Repeat of Orbit #2 (enable detection of apparent motion for satellites seen in orbit #2)
The above sequence of 3 consecutive orbits will be repeated at one additional epoch,
for a total of 2 epochs and 6 orbits.
Note that our observations are in the background noise limited regime.
Scattered and diffracted light from Pluto and Charon dwarf all other background sources.
P4 should be detectable in many of the individual 175s images
(it was detected in 37 of the 48 images taken during cycle 17 [GO-11556] using F350LP with 180s exposure times),
which is a nice feature to have. Using two consecutive orbits allows us to detect the relative motions of satellites
located between the orbits of Charon and Hydra, which provides a powerful tool for distinguishing between artifacts
and real objects in orbit around Pluto. Using 30s exposures allows us to probe the dynamically stable region within ~0.4" of Pluto.
The throughput of the F350LP filter is ~1.6x larger than that of the F606W filter, which was used during our previous 2011 observations.
This sensitivity improvement is critical as P5 and P6 are extremely faint (V≈26.7) and are embedded in bright, scattered light from
Pluto and Charon (V=14 and 16, respectively). The intensity of the scattered light level is well determined from our previous Hubble
observations, and we have used these numbers in the WFC3 ETC to calculate the sensitivity of our planned observations.
The zodiacal light in the ETC is scaled by a factor of 11 to simulate the scattered light level at Nix’s distance from Pluto.
A scaling factor of 170 is used to simulate the scattered light level at ~0.4" from Pluto, which defines the outer edge of the
innermost orbital stability zone. Despite these high background light levels, the ETC shows SNR=9.2 for V=26.7 for a single
orbit of observations at Nix’s distance from Pluto (using a 3 pixel radius aperture; WFC3 ETC ID 231401) when using the 175s exposures.
We find SNR=3.2 is achieved for V=26.0 in a single orbit of observations at ~0.4" from Pluto (WFC3 ETC ID 233059) when using the 30s exposures.
Given the large Pluto-relative motions of objects located within Charon’s orbit, we may have to employ sophisticated
shift-and-add techniques to achieve the full sensitivity. In all cases, we plan to subtract the contributions from Pluto and Charon,
using either images taken from a different epoch or model light distributions.
We have successfully applied both techniques in previous Hubble programs.
We request 3 orbits of observations as soon as possible (e.g., September),
followed by 3 orbits of observations ~6.4 days later.
The 6.4 day cadence is requested to place Pluto and Charon at the same relative location
on the WFC3 CCD (6.4 days is the rotational period of Pluto and Charon around their barycenter),
which will allow us to create a more accurate model for the scattered light from Pluto and Charon
that can be subtracted from images to better reveal any faint satellites. For the same reason,
all observations should be performed at the same Hubble roll angle.SOLAR SYSTEM0false0.00.0falsefalsefalsefalseSUPPORTEDSOLAR SYSTEMPLANETPluto-centerSTD=PLUTOEARTHWFC3/UVISImagingNoNoF350LPUsing ephemeris for target 12725-01-PLUTOephemeris data for target 12725-01-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.182 to 12.214. ephemeris interval: 11.212 to 13.213Timing link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days] [04 After 01 by 6.4 to 6.4 days])Same orient constraint links visits (01 02 03 04 05 06)The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode.131595216500089.0(Tic-Visit
:proposal-id 12725
:visit-id "01"
:proposal-version -1
:trans-version "20110509"
:date "29-Aug-2011 11:17:25.0"
: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 151024
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 12725
:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12725
:visit-id "01"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2821
:al-overhead-at-end 0
:internal-dur-at-end 204
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)false10Using ephemeris for target 12725-02-PLUTOephemeris data for target 12725-02-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.182 to 12.214. ephemeris interval: 11.212 to 13.213Timing link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days] [03 After 02 by 0.0 to 0.1 days])Same orient constraint links visits (01 02 03 04 05 06)The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode.131595791700089.0(Tic-Visit
:proposal-id 12725
:visit-id "02"
:proposal-version -1
:trans-version "20110509"
:date "29-Aug-2011 11:17:27.0"
: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 59504
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 12725
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12725
:visit-id "02"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2881
:al-overhead-at-end 0
:internal-dur-at-end 104
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)false10Using ephemeris for target 12725-04-PLUTOephemeris data for target 12725-04-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.182 to 12.214. ephemeris interval: 11.212 to 13.213Timing link suitability includes constraints ([04 After 01 by 6.4 to 6.4 days] [05 After 04 by 0.0 to 0.1 days])Same orient constraint links visits (01 02 03 04 05 06)The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode.(Tic-Visit
:proposal-id 12725
:visit-id "04"
:proposal-version -1
:trans-version "20110509"
:date "29-Aug-2011 11:17:31.0"
: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 151024
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 12725
:visit-id "04"
:obset-id "04"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12725
:visit-id "04"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2821
:al-overhead-at-end 0
:internal-dur-at-end 204
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)false10Using ephemeris for target 12725-05-PLUTOephemeris data for target 12725-05-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.182 to 12.214. ephemeris interval: 11.212 to 13.213Timing link suitability includes constraints ([05 After 04 by 0.0 to 0.1 days] [06 After 05 by 0.0 to 0.1 days])Same orient constraint links visits (01 02 03 04 05 06)The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode.(Tic-Visit
:proposal-id 12725
:visit-id "05"
:proposal-version -1
:trans-version "20110509"
:date "29-Aug-2011 11:17:33.0"
: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 59504
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
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:visit-id "05"
:obset-id "05"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12725
:visit-id "05"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2881
:al-overhead-at-end 0
:internal-dur-at-end 104
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)false10(Tic-Visit
:proposal-id 12725
:visit-id "01"
:proposal-version -1
:trans-version "20110509"
:date "29-Aug-2011 11:17:25.0"
: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 151024
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
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:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
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(Tic-Orbit
:proposal-id 12725
:visit-id "01"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2821
:al-overhead-at-end 0
:internal-dur-at-end 204
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)false10(Tic-Visit
:proposal-id 12725
:visit-id "02"
:proposal-version -1
:trans-version "20110509"
:date "29-Aug-2011 11:17:27.0"
: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 59504
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 12725
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12725
:visit-id "02"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2881
:al-overhead-at-end 0
:internal-dur-at-end 104
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)false10