HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 4153
PERIOD COVERED: UT July 11, 2006 (DOY 192)
OBSERVATIONS SCHEDULED
ACS/HRC 10512
Search for Binaries Among Faint Jupiter Trojan Asteroids
We propose an ambitious SNAPSHOT program to survey faint Jupiter
Trojan
asteroids for binary companions. We target 150 objects, with the
expectation of acquiring data on about 50%. These objects span Vmag
=
17.5-19.5, a range inaccessible with ground-based adaptive optics.
We
now have a significant sample from our survey of brighter Trojans to
suggest that the binary fraction is similar to that which we find
among
brighter main-belt asteroids, roughly 2%. However, our observations
suggest a higher binary fraction for smaller main-belt asteroids,
probably the result of a different formation mechanism {evident also
from the physical characteristics of the binaries}. Because the
collision environment among the Trojans is similar to that of the
Main
Belt, while the composition is likely to be very different, sampling
the
binary fraction among the fainter Trojans should help us understand
the
collisional and binary formation mechanisms at work in various
populations, including the Kuiper Belt, and help us evaluate
theories
for the origin of the Trojans. Calibration of and constraints on
models
of binary production and collisional evolution can only be done
using
these large-scale, real-life physical systems that we are beginning
now
to find and utilize.
ACS/HRC 10627
A Snapshot Survey of Post-AGB Objects and Proto-Planetary Nebulae
We propose an ACS/HRC snapshot survey of 50 post-AGB sources,
objects
which have evolved from the AGB but may or may not become planetary
nebulae {PNe}. This survey will complement existing HST images of
proto-planetary nebulae {PPNe} and PNe in addressing circumstellar
envelope morphology as a function of: 1} the progenitor star mass;
2}
the chemical composition; and 3} evolutionary stage. We will connect
the
observed diversity of nebualar shapes with the main physical and
chemical conditions characterizing post-AGB objects, to identify the
mechanism that breaks the symmetry of AGB mass loss. To our
knowledge,
no previous HST projects have been specifically designed to address
this
issue. From our database of 360 post-AGB candidates, we have
selected
approximately 50 targets, none of which have been or are being
observed
with HST, to sample different central star masses, chemical
compositions, and evolutionary stages, uniformly across the sky.
These
new data will also provide important constraints to a quantitative
analysis of Spitzer Space Telescope {SST} observations planned for a
similar sample of objects. We will model the HST images and SST
spectra
using our axisymmetric dust code 2-Dust, to derive dust density
distributions, pole to equator density ratios, dust shell masses,
inclination angles as well as dust composition.
ACS/HRC 10598
ACS Imaging of Fomalhaut: A Rosetta Stone for Debris Disks Sculpted
by
Planets
The Sun and roughly 15% of stars are surrounded by dust disks
collisionally replenished by asteroids and comets. Disk structure can
be
directly tied to the dynamical influence of more massive bodies such
as
planets. For example, planetary perturbations offset the center of
our
zodiacal dust disk ~0.01 AU away from the Sun and also maintain a ~40
AU
radius inner edge to our Kuiper Belt. Here we propose follow-up
observation to the first optical detection of reflected light from
dust
grains surrounding the nearby star Fomalhaut using HST/ACS. We find
a
belt of material between 133 and 158 AU radius that has a center
position offset ~15 AU from the stellar position, and with a sharp
inner
edge. A tenuous dust component interior to the belt is also detected
in
the southeast. Given Fomalhaut's proximity to the Sun {7.7 pc},
these
images represent the closest and highest angular resolution view of
an
extrasolar analog to our Kuiper Belt. The center of symmetry offset
and
the sharp inner edge of Fomalhaut's belt are evidence for
planet-mass
objects orbiting the star as predicted by dynamical theory and
simulations. We propose comprehensive follow-up ACS imaging to fully
exploit this discovery and map the disk around its entire
circumference
with higher signal-to-noise and at multiple wavelengths. HST/ACS is
certainly the only facility capable of performing this relatively
wide
field optical study at high contrast ratios and diffraction-limited
resolution. The Cycle 14 data will provide key measurements of belt
width as a function of azimuth, the scattered light color of the
belt
versus the inner dust component, and the azimuthal structure of the
belt. These data will be used to constrain dynamical models of
resonances and shepherding that ultimately elucidate the dynamical
properties of planet-mass objects in the system.
ACS/WFC 10503
The Star Formation Histories of Early Type Dwarf Galaxies in Low
Density
Environments: Clues from the Sculptor Group
We seek HST ACS/WFC time to conduct a detailed study of the stellar
populations of 5 early-type {dE, dE/dIrr} dwarf galaxies in the
nearby
{~1.5 to 4 Mpc} Sculptor group. Four of these systems have been
recently
found to contain modest amounts of HI, and existing ground-based and
HST
snapshot data point to the potential presence of small populations
of
young {blue} stars in at least three of these systems. Consequently,
they resemble the Local Group 'transition' objects Phoenix and LGS3.
The
relative number of such transition systems is thus substantially
larger
in the low density environment of the Scl group than for the Local
Group. Detailed stellar populations studies will allow estimation of
the
star formation histories, via stellar population modelling of the
color-
magnitude diagrams, of the target dwarfs, which in turn will connect
to
gas consumption and retention rates. For the two nearer dwarfs we aim
to
reach below the horizontal branch {a first for any system beyond the
Local Group} equivalent to a main sequence turnoff age of ~1 Gyr.
The
observations of these two systems will also allow detection of RR
Lyrae
variables and thus direct confirmation of the presence of old
populations. For the other three dwarfs will we cover the first 2.5
mags
of the red giant branch, equivalent to the main sequence termination
for
a ~300 Myr population. The results will have implications for
theories
of galaxy formation and evolution, particularly with regard to the
evolutionary relation between low luminosity dEs and dwarf irregulars.
ACS/WFC 10551
Gamma-Ray Bursts from Start to Finish: A Legacy Approach
The progenitors of long-duration GRBs are now known to be massive
stars.
This result lends credence to the collapsar model, where a rotating
massive star ends its life leaving a black hole or a highly
magnetized
neutron star, and confirms its essential aspects. The focus of
attention
now is on the black hole or magnetar engines that power the bursts.
Somehow these engines create the most highly relativistic and highly
collimated outflows that we know of, through mechanisms that no
current
theory can explain. These astrophysical laboratories challenge our
understanding of relativistic shocks, of mechanisms for extracting
energy from a black hole, and of how physics works in extreme
conditions. The launch of Swift is bringing us into a new era, where
we
can make broadband observations that will enable us to study these
fascinating physical processes. We propose here an ambitious,
comprehensive program to obtain the datasets that will become the
standard that any successful model for the central engine must
explain.
This programs leverages the HST observations to the maximum extent
by
our commitment of Swift observations, a Large program at the VLA,
and
extensive ground-based optical resources. By studying the engines
and
searching for jets in a variety of events, this program will
investigate
the conditions necessary for the engine and jet formation itself.
ACS/WFC 10753
An Astrometric Calibration Field Near the Ecliptic Pole
This program will obtain deep ACS astrometry of a Large Magellanic
Cloud
star field lying within the planned continuous viewing zone of the
James
Webb Space Telescope, which extends to a 5 degree radius from the
Ecliptic pole. To allow a full astrometric solution to be
calculated,
controlling for distortions within ACS that may be time variable
over
periods of months to years, we will observe our target field at two
distinct roll angles separated by approximately 90 degrees. To help
control for large scale distortions, we will "chop" the
observations in
at least one roll angle, using offsets of order one third the ACS
field
of view.
FGS 10912
Trigonometric Calibration of the Distance Scale for Classical Novae
The distance scale for classical novae is important for
understanding
the stellar physics of their thermonuclear runaways, their
contribution
to Galactic nucleosynthesis, and their use as extragalactic standard
candles. Although it is known that there is a relationship between
their
absolute magnitudes at maximum light and their subsequent rates of
decline--the well-known maximum-magnitude rate-of-decline {MMRD}
relation--it is difficult to set the zero-point for the MMRD because
of
the very uncertain distances of Galactic novae. We propose to
measure
precise trigonometric parallaxes for the quiescent remnants of the
four
nearest classical novae. We will use the Fine Guidance Sensors,
which
are proven to be capable of measuring parallaxes with errors of ~0.2
mas, well below what is possible from the ground.
FGS 10931
Dynamical Masses and Radii of Four White Dwarf Stars
No Abstract added
NIC1/NC2/NC3 10723
Cycle 14 NICMOS dark current, shading profile, and read noise
monitoring
program
The purpose of this proposal is to monitor the dark current, read
noise,
and shading profile for all three NICMOS detectors throughout the
duration of Cycle 14. This proposal is a slightly modified version
of
proposal 10380 of cycle 13 and 9993 of cycle12 that we cut down some
exposure time to make the observation fit within 24 orbits.
NIC2 10906
The Fundamental Plane of Massive Gas-Rich Mergers: II. The QUEST QSOs
We propose deep NICMOS H-band imaging of a carefully selected sample
of
23 local QSOs. This program is the last critical element of a
comprehensive investigation of the most luminous mergers in the
nearby
universe, the ultraluminous infrared galaxies {ULIRGs} and the
quasars.
This effort is called QUEST: Quasar / ULIRG Evolutionary STudy. The
high-resolution HST images of the QUEST QSOs will complement an
identical set of images on the ULIRG sample obtained during Cycle 12,
an
extensive set of ground-based data that include long-slit NIR
spectra
from a Large VLT Program, and a large set of mid-infrared spectra from
a
Cycle 1 medium-size program with Spitzer. This unique dataset will
allow
us to derive with unprecedented precision structual, kinematic, and
activity parameters for a large unbiased sample of objects spanning
the
entire ULIRG/QSO luminosity function. These data will refine the
fundamental plane of massive gas-rich mergers and enable us to
answer
the following quesitons: {1} Do ultraluminous mergers form
elliptical
galaxies, and in particular, giant ellipticals? {2} Do ULIRGs evolve
into optical bright QSOs? The results from this detailed study of
massive mergers in the local universe will be relevant to
understanding
the basic physical processes involved in creating massive early-type
host on the one hand, and growing/feeding embedded massive black
holes
on the other, in major galaxy mergers. This is an important question
since 50% of cosmic star formation at high-z and most of the big BHs
appear to be formed in this process.
WFPC2 10745
WFPC2 CYCLE 14 INTERNAL MONITOR
This calibration proposal is the Cycle 14 routine internal monitor
for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety
of internal exposures are obtained in order to provide a monitor of
the
integrity of the CCD camera electronics in both bays {both gain 7
and
gain 15 -- to test stability of gains and bias levels}, a test for
quantum efficiency in the CCDs, and a monitor for possible buildup
of
contaminants on the CCD windows. These also provide raw data for
generating annual super-bias reference files for the calibration
pipeline.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary
reports
of potential non-nominal performance that will be investigated.)
HSTARS:
#10358 GSACQ(2,1,2) failed, Search Radius Limit Exceeded on FGS 2 @
192/2203z
GSACQ(2,1,2) at 192/21:58:32 failed due to Search Radius Limit
Exceeded
on FGS 2
at 22:03:11. One 486 status buffer message A05 (FGS Coarse
Track
failed- Search Radius Limit exceeded) was received. OBAD at
21:53:22
prior to GSACQ had total RSS attitude error correction of 18.09
arcseconds. Observations affected: ACS 84 to 86.
COMPLETED OPS REQUEST:
#17820-0 Dump ACS Error Log @ 192/1403z
#17821-0 Genslew for proposal 10598 - slot 1 @ 192/1908z
#17822-0 Genslew for proposal 10598 - slot 2 @ 192/1910z
#17823-0 Genslew for proposal 10598 - slot 3 @ 192/1911z
#17824-0 Genslew for proposal 10598 - slot 4 @ 192/1912z
#17825-0 Genslew for proposal 10598 - slot 5 @ 192/1913z
#17826-0 Genslew for proposal 10598 - slot 6 @ 192/1914z
#17827-0 Genslew for proposal 10598 - slot 7 @ 192/1915z
#17828-0 Genslew for proposal 10598 - slot 8 @ 192/1916z
#17818-0 Battery 3 Capacity Test Script & 5 Battery Pressure
Limit COP (thru step 18)
@ 192/2134z
COMPLETED OPS NOTES:
#1504-0 Change JERRCNT Limit @ 192/1406z
SCHEDULED
SUCCESSFUL FAILURE TIMES
FGS
GSacq
5
4
192/2158z (HSTAR 10358)
FGS
REacq
7
7
OBAD with Maneuver
20
20
SIGNIFICANT EVENTS:
Battery 3 Capacity Test Flash Report #1
Commanding for the Battery 3 Capacity Test started as scheduled on
DOY
192/1205 GMT (07/11 at 8:05 am) with setting the Battery Pressure
Test
for a 5-battery system. Battery 3 was taken off-line and discharged
on
the first opportunity at 1228 GMT (07/11 at 8:28 am). Following
completion of the discharge, Battery 3 will be placed back on-line
in
hardware during orbit night. Following its recovery period, Battery
3
will be placed back on-line in FSW on 195/1400 GMT (07/14 at 10:00 am).
Battery 3 Capacity Test Flash Report #2
The battery 3 high-rate discharge terminated 192/2134 GMT (07/11 at
5:34
pm). The low rate discharge is now in progress and is expected
to terminate at approximately 194/1200 (Thursday, 7/13 at 8am).
-Lynn
Lynn F. Bassford
CHAMP HST Missions Operations Manager
Lockheed Martin Technical Operations
GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the Babe Ruth of astronomical
observatories, the Muhammad Ali of cosmic photography
"
- Robert Roy Britt, space.com 7-14-4
..............................................................