0Assigned ID: 1217
----- Attempting Submission 1 (Fri Oct 02 03:00:50 GMT 2015) -----URGENT: Please schedule visit 1 as soon as possible, and the last 3 visits in sequence as late as possible before solar exclusion (on Dec 18). Exposure times can be reduced for schedulability, but do so uniformly. - Thanks, Max Mutchler
link opened a little to allow enough of a window to start orbit 3 in orbit 3.648462295----- Attempting Submission 1 (Tue Nov 24 01:48:15 GMT 2015) -----
----- Attempting Submission 2 (Tue Nov 24 13:41:48 GMT 2015) -----Hubble Investigation of Active Asteroid 324P/La SagraActive asteroid 324P/La Sagra has recently reactivated. We propose WFC3 observations to characterize the activity, to measure the size distribution of the ejected dust, its velocity and the time profile of the mass production rate. These Mid-Cycle observations will be combined with observations from our Cycle 23 (2-orbit) ToO program GO 14263 in order to produce the best possible dataset for this body. Reactivation of an active asteroid near perihelion suggests that sublimating ice is the activity driver. 324P/La Sagra orbits near 3 AU, widely posited as a likely source region for the Earth's oceans and other volatiles. Characterizing ice in the asteroid belt is scientifically interesting in the broad context of the origin of planetary volatiles.We request four HST orbits to image La Sagra, with one scheduled as early as possible in November and three as close as possible to December 19 to study the nucleus and capture the object from an in-plane perspective, which provides data that are particularly diagnostic of the dust velocity distribution. Our basic observing strategy is to take multiple long exposures (400 s) using WFC3 and a wide bandpass filter (F350LP) for maximum sensitivity. (In some previous HST programs we used long exposures through the F606W filter to provide maximum sensitivity. The F350LP filter provides an 1.6 higher count rate for a target with a solar-type spectrum.) We also plan to dither the exposures to mitigate the effects from bad pixels, cosmic rays, and the inter-chip gap. We already have observations from Sep 29 (orbit plane angle 10 degrees), and observations for Oct 8 are already scheduled under our two-orbit ToO program 14263. Two additional visits, as early in November as practical (3 degrees) and as close as possible to the Dec 19 Sun exclusion zone (0 degrees), will provide sufficient input to derive the properties of the dust coma from the dynamical models. To test the role of spin in 324P, we request 3 consecutive or near-consecutive orbits to sample the nucleus lightcurve over a 3 hour interval. Observations over 3 hours will allow us to measure the lightcurve over slightly more than one period, in order to ensure that periodicity has been detected. The apparent rates of motion are 30 arcsec per hour, which are easily within Hubble's tracking capabilities. This rate of motion is also slow enough to keep a single pair of guide stars within the FGS pickles for an entire visibility window. The ephemeris uncertainty of La Sagra is negligible (sub-arcsecond), compared to the WFC3 field-of-view. Ephemeris issues are of no concern to this observation. We understand that we will have essentially no control over the spacecraft roll angle, which means we will not be able to optimize the orientation of the dust tail on the CCD (i.e., to orient the tail along the longest dimension of the detector). However, the field-of-view of the camera is large enough that we should obtain excellent data on a portion of the tail, no matter what spacecraft roll angle is used.SOLAR SYSTEM12falsefalsefalsefalseSUPPORTEDSOLAR SYSTEMYESASTEROIDactive asteroid, Main Belt CometTYPE=COMET,Q=2.619823310911345,E=.153784445570409,I=21.41695747394586,O=270.6516569004608,W=58.56915804482286,T=29-NOV-2015:22:58:09,TTimeScale=UTC,EQUINOX=J2000,EPOCH=28-AUG-2015:00:00:00,EpochTimeScale=TDBEARTHWFC3/UVISImagingNoNoF350LPWFC3/UVISImagingNoNoF350LPUsing ephemeris for target 14458-01-324P-LA-SAGRAephemeris data for target 14458-01-324P-LA-SAGRA does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 15.190 to 17.089. ephemeris interval: 15.304 to 17.305The scheduling data was generated by CASM 23.2.CASM was run in Phase II mode.Please schedule this visit as soon as possible.(Tic-Visit
:proposal-id 14458
:visit-id "01"
:proposal-version -1
:trans-version "20150609"
:date "23-Nov-2015 20:44:37.0"
: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 1443744
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 14458
:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 14458
:visit-id "01"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2816
: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 3210
:pcs-gap 0
)true10Using ephemeris for target 14458-02-324P-LA-SAGRAephemeris data for target 14458-02-324P-LA-SAGRA does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 15.190 to 17.089. ephemeris interval: 15.304 to 17.305Timing link suitability includes constraints ([Sequence (02 03 04) within 0.2 days])The scheduling data was generated by CASM 23.2.CASM was run in Phase II mode.Please schedule visits 2,3,4 in sequence as late as possible before solar exclusion begins.(Tic-Visit
:proposal-id 14458
:visit-id "02"
:proposal-version -1
:trans-version "20150609"
:date "23-Nov-2015 20:44:38.0"
: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 1443744
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 14458
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 14458
:visit-id "02"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2816
: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 3210
:pcs-gap 0
)true10Using ephemeris for target 14458-03-324P-LA-SAGRAephemeris data for target 14458-03-324P-LA-SAGRA does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 15.190 to 17.089. ephemeris interval: 15.304 to 17.305Timing link suitability includes constraints ([Sequence (02 03 04) within 0.2 days])The scheduling data was generated by CASM 23.2.CASM was run in Phase II mode.Please schedule visits 2,3,4 in sequence as late as possible before solar exclusion begins.(Tic-Visit
:proposal-id 14458
:visit-id "03"
:proposal-version -1
:trans-version "20150609"
:date "23-Nov-2015 20:44:39.0"
: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 1443744
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 14458
:visit-id "03"
:obset-id "03"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 14458
:visit-id "03"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2816
: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 3210
:pcs-gap 0
)true10Using ephemeris for target 14458-04-324P-LA-SAGRAephemeris data for target 14458-04-324P-LA-SAGRA does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 15.190 to 17.089. ephemeris interval: 15.304 to 17.305Timing link suitability includes constraints ([Sequence (02 03 04) within 0.2 days])The scheduling data was generated by CASM 23.2.CASM was run in Phase II mode.Please schedule visits 2,3,4 in sequence as late as possible before solar exclusion begins.(Tic-Visit
:proposal-id 14458
:visit-id "04"
:proposal-version -1
:trans-version "20150609"
:date "23-Nov-2015 20:44:39.0"
: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 1443744
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 14458
:visit-id "04"
:obset-id "04"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 14458
:visit-id "04"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2816
: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 3210
:pcs-gap 0
)true10