HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #
4164
PERIOD COVERED: UT July 26, 2006 (DOY 207)
OBSERVATIONS SCHEDULED
ACS/HRC 10738
Earth Flats
Sky flats will be obtained by observing the bright Earth with the
HRC
and WFC. These observations will be used to verify the accuracy of
the
flats currently in the pipeline and to monitor any changes. Weekly
coronagraphic monitoring is required to assess the changing position
of
the spots.
ACS/HRC 10800
Kuiper Belt Binaries: Probes of Early Solar System Evolution
Binaries in the Kuiper Belt are a scientific windfall: in them we
have
relatively fragile test particles which can be used as tracers of
the
early dynamical evolution of the outer Solar System. We propose to
continue a Snapshot program using the ACS/HRC that has a
demonstrated
discovery potential an order of magnitude higher than the HST
observations that have already discovered the majority of known
transneptunian binaries. With this continuation we seek to reach the
original goals of this project: to accumulate a sufficiently large
sample in each of the distinct populations collected in the Kuiper
Belt
to be able to measure, with statistical significance, how the
fraction
of binaries varies as a function of their particular dynamical paths
into the Kuiper Belt. Today's Kuiper Belt bears the imprints of the
final stages of giant-planet building and migration; binaries may
offer
some of the best preserved evidence of that long-ago era.
ACS/HRC 10805
ACS Imaging of Uranus' Atmosphere Near Equinox
Uranus' 97-degree spin axis inclination results in the largest
fractional seasonal variation of solar insolation in the solar
system.
Uranus is now close to its 7 December 2007 equinox, and we can now
see
most of the northern hemisphere, which was in darkness when Voyager
provided our first detailed view of the planet in 1986. If Uranus'
seasonal response has the large phase shift expected from its long
radiative time constant, it should now exhibit nearly maximal
hemispheric contrast. Although the long time constant also suggests
a
small physical response, significant hemispheric asymmetries in
cloud
structure and dynamics are becoming apparent. We propose a detailed
characterization of Uranus' current response to this forcing with a
10-orbit program consisting of 4 orbits of WFC imaging with
narrowband
ramp filters and 6 orbits of HRC imaging using both broadband and
narrowband filters. Nine narrow-band filters between 0.62 and 0.955
microns will provide vertical sensing depths scanning through the
pressure range where the putative methane and deeper H2S clouds
might
plausibly exist and provide strong constraints on their optical
properties and parent gas mixing ratios. The high resolution HRC
images
will characterize the dynamics of discrete features at the 15-30
hour
time scale unavailable from the ground. Short wavelength HRC images
will
enable a characterization of the stratospheric haze. These
observations
have unique combinations of spectral range and resolution with
needed
temporal and spatial resolution not available from groundbased
observations.
ACS/HRC/WFC 10758
ACS CCDs daily monitor
This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in
ACS CCD detectors. The files, biases and dark will be used to create
reference files for science calibration. This programme will be for
the
entire lifetime of ACS. Changes from cycle 13:- The default gain for
WFC
is 2 e- /DN. As before bias frames will be collected for both gain 1
and
gain 2. Dark frames are acquired using the default gain {2}. This
program cover the period May, 31 2006- Oct, 1- 2006. The first half
of
the program has a different proposal number: 10729.
ACS/WFC 10846
The Halo Structure of RCS2-2327.4-0204
We propose ACS, NICMOS, and Chandra observations of the central
region
of the extraordinary and newly discovered galaxy cluster:
RCS2-2327.4-0204 at z=0.700. This cluster shows 3 or more arcs in
ground-based imaging, with an Einstein radius of 49". Such a
large
Einstein radius {3-4 times larger than seen in most clusters} has
been
seen in precisely one other cluster in the universe - namely Abell
1689
at z=0.18. From our proposed data we expect to see ~70 lensed source
images, from ~20 image families. We will use both strong and weak
lensing constraints from these data to construct the central mass
profile of the cluster, which, when combined with ground based data
extending to a half degree FOV, will allow us to measure critically
important dark matter halo parameters {such as concentration}. The
target cluster is selected from a large ongoing survey with a
well-defined search volume, which allows us to compare our results
to
expectations from simulations. We will also compare the lensing
derived
mass profiles to the x-ray equivalent measures; this will illuminate
whether the dominant baryonic component is in equilibrium with the
potential. The area of high magnification behind this cluster is an
order of magnitude larger than typical lensing clusters observed
previously by HST; this order of magnitude increase in area directly
translates into a 10 times better chance for finding very high
redshift
galaxies. Many of the highest redshift galaxies found to date have
been
found behind massive lensing clusters observed by HST, and we expect
to
add to that sample dramatically.
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
A new procedure proposed to alleviate the CR-persistence problem of
NICMOS. Dark frames will be obtained immediately upon exiting the
SAA
contour 23, and every time a NICMOS exposure is scheduled within 50
minutes of coming out of the SAA. The darks will be obtained in
parallel
in all three NICMOS Cameras. The POST-SAA darks will be non-
standard
reference files available to users with a USEAFTER date/time mark.
The
keyword 'USEAFTER=date/time' will also be added to the header of
each
POST-SAA DARK frame. The keyword must be populated with the time, in
addition to the date, because HST crosses the SAA ~8 times per day
so
each POST-SAA DARK will need to have the appropriate time specified,
for
users to identify the ones they need. Both the raw and processed
images
will be archived as POST-SAA DARKSs. Generally we expect that all
NICMOS
science/calibration observations started within 50 minutes of leaving
an
SAA will need such maps to remove the CR persistence from the
science
images. Each observation will need its own CRMAP, as different SAA
passages leave different imprints on the NICMOS detectors.
NIC2 10849
Imaging Scattered Light from Debris Disks Discovered by the Spitzer
Space Telescope around 21 Sun-like Stars
We propose to use the high-contrast capability of the NICMOS
coronagraph
to image a sample of newly discovered circumstellar disks associated
with Sun-like stars. These systems were identified by their strong
thermal infrared {IR} emission with the Spitzer Space Telescope as
part
of the Spitzer Legacy Science program titled "The Formation and
Evolution of Planetary Systems" {FEPS, P.I.: M.Meyer}. Modeling of
the
thermal excess emission from the spectral energy distributions alone
cannot distinguish between narrowly confined high-opacity disks and
broadly distributed, low-opacity disks. By resolving light scattered
by
the circumstellar material, our proposed NICMOS observations can
break
this degeneracy, thus revealing the conditions under which planet
formation processes are occuring or have occured. For three of our
IR-excess stars that have known radial-velocity planets, resolved
imaging of the circumstellar debris disks may further offer an
unprecedented view of planet-disk interactions in an extrasolar
planetary system. Even non-detections of the light scattered by the
circumstellar material will place strong constraints on the disk
geometries, ruling out disk models with high optical depth. Unlike
previous disk imaging programs, our program contains a well-defined
sample of ~1 solar mass stars covering a range of ages from 3 Myr to
3
Gyr, thus allowing us to study the evolution of disks from primordial
to
debris for the first time. The results from our program will greatly
improve our understanding of the architecture of debris disks around
Sun-like stars, and will create a morphological context for the
existence of our own solar system. This proposal is for a
continuation
of an approved Cycle 14 program {GO/10527, P.I.: D. Hines}.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies:
(The following are preliminary reports of potential non-nominal
performance that will be investigated.)
HSTARS:
#10376 GSAcq (2,1,1) failed due to Scan Step Limit Exceeded on FGS
2 @ 207/14:13:41z
Observations affected: ACS 90. Same guide star pair used in HSTAR 10372.
OBAD #1:
V1 -434.44, V2 3657.35, V3 52.30, RSS 3683.43.
OBAD #2:
V1 0.68, V2 -3.06, V3 0.31, RSS 3.15.
OBAD MAP @
207/14:43:41 indicated the following: V1 -781.82, V2 4505.00,
V3
-128.39, RSS 4574.14
#10378 GSacq(2,11) failed to RGA control @ 207/18:21:17z
During
LOS, GSAcq(2,11) failed due to stop flag QF2STOPF on
FGS 2.
OBAD2 showed errors of V1=0.15, V2=-6.58, V3=-6.28, RSS=9.10.
Observation affected: ACS 94
#10379 GSacaq(2,1,1) failed due to scan step limit exceeded on FGS
2 @ 207/21:33:08z
This is
the same guide star that failed in HSTARs 10372, 10376, and 10378.
Observations affected: ACS 97
#10380 GSACQ(2,1,1) failed @ 208/00:43:29z
During
LOS, FGS2 scan step flag QF2SSLEX and stop flag QF2STOPF were
set.
NICMOS 705 status buffer message (TDF down when a target
acquisition SAM request is made) with parameter 0 and time 32142
occurred
at 00:52:39. Further information will be available after next
SSR
engineering recorder dump. Observations affected: NICMOS 29 to 31.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSacq
10
06
FGS
REacq
03 01
OBAD with Maneuver
26
26
SIGNIFICANT EVENTS: (None)
-Lynn
Lynn F. Bassford
CHAMP HST Missions Operations Manager
Lockheed Martin Technical Operations
GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the astronomical observatory and
key to unlocking the most cosmic mysteries of the past, present and
future." - 7/26/6
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