Re-submitted, after checking the ToO box.Assigned ID: 82
----- Attempting Submission 1 (Tue Feb 22 21:57:09 GMT 2011) -----
HST Phase I Proposal 82 (mbc_too_phase1.apt) successfully submitted.
----- Attempting Submission 2 (Tue Feb 22 22:28:25 GMT 2011) -----During recent ground-based observations of asteroid 300163 (2006 VW139),
it displayed a tail indicating either it has suffered a collision, or it is a Main Belt Comet (MBC).
We are triggering this Target of Opportunity program on this event.
The Earth is very nearly in the asteroid's orbital plane on 12/15/2011, and we'd
like one of our visits to be as close to that time as possible. The other visit should
be ~10 days before (i.e., near 12/5/2011 +/- 2 days) or 10 days after (i.e., near
12/25/2011 +/- 2 days).
shortened the last exposure from 350s -> 250s.----- Attempting Submission 1 (Wed Jul 06 23:48:17 GMT 2011) -----
----- Attempting Submission 2 (Mon Nov 21 04:45:52 GMT 2011) -----
----- Attempting Submission 3 (Mon Nov 21 14:00:18 GMT 2011) -----For some reason, APT is not fitting in the 6th WFC3 exposure of each visit, although
I *think* this exposure should fit. If you find that a 6th image cannot fit in the orbit,
please shorten the exposure time of that image only to whatever is needed to match
the available time. We *cannot* lengthen any exposure times beyond 350 sec because
the MBC's nucleus might saturate then.Hubble Imaging of a Newly Discovered Main Belt CometWe seek two orbits of Target of Opportunity (ToO) time to secure
exploratory observations of a main-belt comet (MBC), should one be
discovered in the upcoming proposal cycle. The observations will be
used to determine the early-time morphology and to assess its rate of
change by comparison of data from two epochs. The ToO data are needed
to determine the optimum strategy for subsequent observations, intended
to characterize the MBC at the highest resolution and so to determine
the driver of the cometary activity. Our previous Hubble observations
of MBCs P/2010 A2 and (596) Scheila were obtained in emergency mode
through Director's Discretionary Time requests. The Director's office
has suggested that we propose to follow up future MBC discoveries as a
ToO, so that HST observations could begin sooner.Our observing strategy will be dictated by the specific target discovered. For an MBC
having a relatively faint nucleus (e.g., P/2010 A2), we expect to take 5 or 6 images with
long exposure times (400-500 s) in a broadband filter (F606W) to provide a deep search
for debris. But if the MBC has a relatively bright nucleus, we will take both short and long
exposures, and possibly use a narrow band filter for the short exposures. For example, for
asteroid (596) Scheila with its ultra-bright nucleus (V=13.7), we used an exposure time of
0.5 sec (the shortest available) and the F621M filter to avoid saturation while still obtaining
S/N=200 on the nucleus itself in search of structure at 100 km scales. In all cases, we
will obtain approximately half the images at one location on the CCD and then repeat
that sequence of images at a dithered location. Dithered, multiple images provide protection
from bad pixels and cosmic ray strikes that otherwise might compromise the photometry.
Previous HST observations show that the timescale for substantial change is from several
weeks (Scheila) to several months (P/2010 A2). Therefore, while the first observation should
be scheduled as soon as possible after the target is discovered, the science does not require
that the first visit be secured within the first two weeks.
The first visit will set the scene, by establishing the high-resolution morphology of the
object (at ~60 km/pixel at 2 AU geocentric distance). The second visit, ideally separated
from the first by ~10 days, will reveal the changes. The two visits together will allow us to
make a rational decision about the need for further observations with HST.This is a Target of Opportunity program that will be activated upon the discovery of a new
Main Belt Comet. Please note that the orbital elements must be updated with those of the
newly discovered object *before* doing any detailed planning of the observations.SOLAR SYSTEM12false0.00.0falsefalsefalsefalseSUPPORTEDSOLAR SYSTEMMain belt asteroid 300163 (2006 VW139) has recently been identified
as a Main Belt Comet (MBC).COMETMain Belt CometTYPE=COMET,Q=2.4378652,E=0.2011255,I=3.23918,O=83.20655,W=281.88617,T=18-JUL-2011:13:00:05,TTimeScale=TDB,EQUINOX=J2000,EPOCH=27-AUG-2011:00:00:00,EpochTimeScale=TDBEARTHWFC3/UVISImagingNoNoF606W/private/var/folders/Pi/PiItoBTTEo4iuUPDCliQok++5+6/-Tmp-/OPVisit1803644349282913913.xmlUsing ephemeris for target 12597-01-MBC-300163ephemeris data for target 12597-01-MBC-300163 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.213 to 13.091. ephemeris interval: 11.304 to 13.305Timing link suitability includes constraints ([02 After 01 by 8.0 to 12.0 days])The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode.(Tic-Visit
:proposal-id 12597
:visit-id "01"
:proposal-version -1
:trans-version "20110825"
:date "21-Nov-2011 08:57:08.0"
: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 1732496
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 12597
:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12597
:visit-id "01"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2844
:al-overhead-at-end 0
:internal-dur-at-end 670
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)true10/private/var/folders/Pi/PiItoBTTEo4iuUPDCliQok++5+6/-Tmp-/OPVisit4275411361426704033.xmlUsing ephemeris for target 12597-02-MBC-300163ephemeris data for target 12597-02-MBC-300163 does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.213 to 13.091. ephemeris interval: 11.304 to 13.305Timing link suitability includes constraints ([02 After 01 by 8.0 to 12.0 days])The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode.(Tic-Visit
:proposal-id 12597
:visit-id "02"
:proposal-version -1
:trans-version "20110825"
:date "21-Nov-2011 08:59:33.0"
: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 1732496
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 12597
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 12597
:visit-id "02"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2844
:al-overhead-at-end 0
:internal-dur-at-end 670
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)true10