Alison, call me immediately (410-338-1321) if you see any problems here, or have any suggestions for improvement. ----- Attempting Submission 1 (Thu Oct 25 19:31:07 GMT 2007) ----- Call me with issues (410-338-1321). Max Mutchler This is a DD proposal that should be implemented at the earliest available opportunity. Please contact Max Mutchler for technical implementation details. Assigned ID: 2049 ----- Attempting Submission 1 (Thu Oct 25 11:23:16 GMT 2007) ----- Investigating the Spectacular Outburst of Comet 17P/Holmes Comet 17P/Holmes is currently undergoing a spectacular eruption in activity, with its brightness increasing by ~14 mag over a 24 hour period. The comet is shedding huge amounts of dust, presumably associated with a major splitting event at the nucleus. The high spatial resolution and high sensitivity of Hubble has proven to be invaluable during previous observations of several fragmenting comets, and the 2007 apparition of 17P/Holmes represents another excellent opportunity to investigate this important cometary phenomenon. We request 3 orbits of WFPC2 observations to measure the size and V-R color of the principal nucleus, perform a deep search for large fragments released during the outburst, monitor the temporal development of the event, and search for a satellite whose collision with the principal nucleus may have triggered the current outburst, as was suggested for the similar outburst observed in 1892.
Three identical visits separated by 1-2 days over the next week. Two long exposures in each of two filters, with a small dither shift between them, to mitigate against any bad pixels. One short exposure in each filter, to ensure at least one unsaturated image. The exposures are sequenced to minimize overheads due to filter changes and dither shifts. The long exposures wil be combined to make clean images, and they are separated as much as possible to help with the rejection of star trails. SOLAR SYSTEM 0 false 0.0 false false false false false false SUPPORTED SOLAR SYSTEM COMET Comet in outburst TYPE=COMET,Q=2.0531685968984,E=0.4324195317478002,I=19.11330875529636,O=326.8673862726764,W=24.25862184788592,T=04-MAY-2007:11:59:44,EQUINOX=J2000,EPOCH=01-MAY-2007:00:00:00,A1=1.701164E-9,A2=2.844799E-10 WFPC2 Imaging No F675W WFPC2 Imaging No F555W POS-TARG DITHER 0.3535 LINE false false 2 45 WFPC2-LINE 1 false true /Users/mutchler/apt/11418/OP-cache/11418-v01.xml (Tic-Visit :proposal-id 11418 :visit-id "01" :proposal-version -1 :trans-version "20070709" :date "25-Oct-2007 15:05:28.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11418 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11418 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Long exposure to detect any trailing debris or orbiting satellites Long exposure to detect any trailing debris or orbiting satellites Short exposure ensure at least one unsaturated image Short exposure ensure at least one unsaturated image Long exposure to detect any trailing debris or orbiting satellites Long exposure to detect any trailing debris or orbiting satellites true /Users/mutchler/apt/11418/OP-cache/11418-v02.xml (Tic-Visit :proposal-id 11418 :visit-id "02" :proposal-version -1 :trans-version "20070709" :date "25-Oct-2007 15:11:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11418 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11418 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 false /private/tmp/OPVisit39736.xml Long exposure to detect any trailing debris or orbiting satellites Long exposure to detect any trailing debris or orbiting satellites Short exposure ensure at least one unsaturated image Short exposure ensure at least one unsaturated image Long exposure to detect any trailing debris or orbiting satellites Long exposure to detect any trailing debris or orbiting satellites true /Users/mutchler/apt/11418/OP-cache/11418-v03.xml (Tic-Visit :proposal-id 11418 :visit-id "03" :proposal-version -1 :trans-version "20070709" :date "25-Oct-2007 15:11:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11418 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11418 :visit-id "03" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 false /private/tmp/OPVisit39736.xml Long exposure to detect any trailing debris or orbiting satellites Long exposure to detect any trailing debris or orbiting satellites Short exposure ensure at least one unsaturated image Short exposure ensure at least one unsaturated image Long exposure to detect any trailing debris or orbiting satellites Long exposure to detect any trailing debris or orbiting satellites