This version adds the F435W filter to visit 2, as approved by STScI Director Matt Mountain. ----- Submission 1 (Thu Dec 08 19:16:38 GMT 2005) ----- ----- Submission 2 (Mon Jan 30 16:42:07 GMT 2006) ----- Phase II Proposal 10774 (10774) successfully submitted. ----- Submission 3 (Mon Jan 30 21:01:39 GMT 2006) ----- ----- Submission 4 (Fri Feb 17 21:05:45 GMT 2006) ----- Not sure what thge problem is -- Isee no diagnostics, and I just reprocessed it. I did notice that a new version of APT was released TODAY (what are the odds!), so maybe that explains it. Both Alan Stern and I (Weaver) are currently at KSC in Florida on New Horizons mission business. If necessary, you can reach us via cell phone at 410-978-5172 (Weaver) and 303-324-5269 (Stern). Assigned ID: 1028 ----- Submission 1 (Tue Aug 30 13:08:52 GMT 2005) ----- Confirming the Discovery of Two New Satellites of Pluto We detected two new objects ~2 arcsec from Pluto during our recent deep search for companions using the ACS / WFC mode (HST GO program 10427). Either these objects are newly discovered satellites of Pluto, or they are previously undiscovered Plutino KBOs that happened to be located along the line-of-sight to Pluto. The ramifications are enormous for our understanding of the origin and evolution of the Pluto-Charon system, and for our understanding of KBO satellite formation in general, if these new objects are satellites of Pluto. Thus, we request two orbits of HST observing time as soon as possible, to confirm that these newly discovered objects are truly satellites of Pluto.
These observations will be very similar to our ACS / WFC observations of Pluto (HST GO program 10427), where we first discovered the new satellites S/2005 P 1 and S/2005 P 2. However, since these objects were detected within a few arcseconds of Pluto-Charon, we will now utilize the ACS / HRC instead. The HRC field-of-view (~29x26 arcseconds) is much smaller than the WFC, but still easily large enough to image the entire system, and at higher resolution. Although the orbits of P1 and P2 are not definitively determined yet, we believe they are Charon-like and essentially circular, so they should never be more than a few arcseconds from Pluto. We employ a sub-pixel dither box pattern, both to avoid bad detector pixels and to improve the spatial sampling as much as possible. At each dither point we take one long exposure, where Pluto-Charon will be saturated (with some bleeding along the CCD columns), and where we expect to detect P1 and P2. We also take at least one short (1 second) exposure at each dither point, where P1 and P2 will not be detected, but Pluto and Charon will be unsaturated and provide additional positional information which will aid in the registration of the images. The short exposures would also reveal (and allow us to correct for) any drift in the moving target tracking, which we otherwise expect to be accurate to within a fraction of a pixel (i.e. good enough to faithfully execute a sub-pixel dither pattern). Then we repeat these observations in an identical visit, about 15 days days later (which is roughly half of the orbital period of both satellites), to confirm the orbital motion of the objects. We expect these observations to confirm the status of P1 and P2 as satellites of Pluto, and further constrain their orbital elements. We would like the first epoch (orbit) of this program to execute as soon as possible after Pluto becomes observable again by HST (in 2 gyro mode) around 15 February 2006. Note as of 17 Feb 2006: After analyzing the first visit, which completely verified the existence and orbits of P1 and P2, our team was given permission by the STScI Director (Matt Mountain) to modify visit 2 to incorporate another filter (we chose B-band F435W). SOLAR SYSTEM 0 false 0.0 false false false false false SUPPORTED SOLAR SYSTEM PLANET Pluto STD=PLUTO ACS/HRC Imaging No No F606W ACS/HRC Imaging No No F606W POS-TARG DITHER 1.9 This shift spans the HRC occulting finger, to ensure that neither satellite P1 and P2 can be hidden behind the finger in all 4 exposures. LINE false false 2 5.85 ACS-HRC-DITHER-LINE 1 false POS-TARG DITHER 0.15 LINE 0.098 false false 63.5 4 19.89 ACS-HRC-DITHER-BOX 2 false POS-TARG DITHER 0.198 LINE false false 2 44.28 ACS-HRC-DITHER-LINE 3 false /milan/data3/pluto_10774/apt_visit2/OP-cache/10774-v01.xml (Tic-Visit :proposal-id 10774 :visit-id "01" :proposal-version -1 :trans-version "20051113" :date "17-Feb-2006 15:02:15.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 184016 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10774 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10774 :visit-id "01" :orbit-number 1 :pcs-time 339 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 240 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 /private/tmp/OPVisit64879.xml /milan/data3/pluto_10774/apt_visit2/OP-cache/10774-v02.xml (Tic-Visit :proposal-id 10774 :visit-id "02" :proposal-version -1 :trans-version "20051113" :date "17-Feb-2006 15:44:55.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 147216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10774 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10774 :visit-id "02" :orbit-number 1 :pcs-time 339 :si-vis-utilization 2562 :al-overhead-at-end 0 :internal-dur-at-end 199 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 /private/tmp/OPVisit64880.xml