HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4685
PERIOD COVERED: 5am August 28 - 5am August 29, 2008 (DOY
241/0900z-242/0900z)
OBSERVATIONS SCHEDULED
FGS 11210
The Architecture of Exoplanetary Systems
Are all planetary systems coplanar? Concordance cosmogony
makes that
prediction. It is, however, a prediction of extrasolar
planetary system
architecture as yet untested by direct observation for
main sequence
stars other than the Sun. To provide such a test, we
propose to carry
out FGS astrometric studies on four stars hosting seven
companions. Our
understanding of the planet formation process will grow as
we match not
only system architecture, but formed planet mass and true
distance from
the primary with host star characteristics for a wide
variety of host
stars and exoplanet masses. We propose that a series of
FGS astrometric
observations with demonstrated 1 millisecond of arc
per-observation
precision can establish the degree of coplanarity and
component true
masses for four extrasolar systems: HD 202206 {brown
dwarf+planet}; HD
128311 {planet+planet}, HD 160691 = mu Arae {planet+planet},
and HD
222404AB = gamma Cephei {planet+star}. In each case the
companion is
identified as such by assuming that the minimum mass is
the actual mass.
For the last target, a known stellar binary system, the
companion orbit
is stable only if coplanar with the AB binary orbit.
NIC1 11205
The Effects of Multiplicity on the Evolution of Young
Stellar Objects: A
NICMOS Imaging Study
We propose to use NICMOS to investigate the multiplicity
of young
stellar objects (YSOs) in the Orion B molecular cloud.
Previous
observations with the Spitzer Space Telescope have
revealed a remarkable
star forming filament near the NGC 2068 reflection nebula.
The
population of YSOs associated with the filament exhibit a
surprisingly
wide range of circumstellar evolutionary states, from
deeply embedded
protostars to T Tauri accretion disks. Many of the
circumstellar disks
themselves show evidence for significant dust evolution,
including grain
growth and settling and cleared inner holes, apparently in
spite of the
very young age of these stars. We will estimate the binary
fraction of a
representative sample of objects in these various stages
of evolution in
order to test whether companions may play a significant
role in that
evolution.
NIC1/NIC2/NIC3 11820
NICMOS Post-SAA Calibration - CR Persistence Part 7
Internals for CR persistence
NIC2 11237
The Origin of the Break in the AGN Luminosity Function
We propose to use NICMOS imaging to measure rest-frame
optical
luminosities and morphological properties of a complete
sample of faint
AGN host galaxies at redshifts z ~ 1.4. The targets are
drawn from the
VLT-VIMOS Deep Survey, and they constitute a sample of the
lowest
luminosity type 1 AGN known at z > 1. The spectroscopically
estimated
black hole masses are up to an order of magnitude higher
than expected
given their nuclear luminosities, implying highly
sub-Eddington
accretion rates. This exactly matches the prediction made
by recent
theoretical models of AGN evolution, according to which
the faint end of
the AGN luminosity function is populated mainly by big
black holes that
have already exhausted a good part of their fuel. In this
proposal we
want to test further predictions of that hypothesis, by
focusing on the
host galaxy properties of our low-luminosity, low-
accretion AGN. If the
local ratio between black hole and bulge masses holds at
least
approximately at these redshifts, one expects most of
these
low-luminosity AGN to reside in fairly big ellipticals
with stellar
masses around and above 10^11 solar masses (in contrast to
the Seyfert
phenomenon in the local universe). With NICMOS imaging we
will find out
whether that is true, implying also a sensitive test for
the validity of
the M_BH/M_bulge relation at z ~ 1.4.
NIC2 11548
NICMOS Imaging of Protostars in the Orion A Cloud: The
Role of
Environment in Star Formation
We propose NICMOS observations of a sample of 252
protostars identified
in the Orion A cloud with the Spitzer Space Telescope.
These
observations will image the scattered light escaping the
protostellar
envelopes, providing information on the shapes of outflow
cavities, the
inclinations of the protostars, and the overall
morphologies of the
envelopes. In addition, we ask for Spitzer time to obtain
55-95 micron
spectra of 75 of the protostars. Combining these new data
with existing
3.6 to 70 micron photometry and forthcoming 5-40 micron
spectra measured
with the Spitzer Space Telescope, we will determine the
physical
properties of the protostars such as envelope density,
luminosity,
infall rate, and outflow cavity opening angle. By
examining how these
properties vary with stellar density (i.e. clusters vs
groups vs
isolation) and the properties of the surrounding molecular
cloud; we can
directly measure how the surrounding environment
influences protostellar
evolution, and consequently, the formation of stars and
planetary
systems. Ultimately, this data will guide the development
of a theory of
protostellar evolution.
WFPC2 11113
Binaries in the Kuiper Belt: Probes of Solar System
Formation and
Evolution
The discovery of binaries in the Kuiper Belt and related
small body
populations is powering a revolutionary step forward in
the study of
this remote region. Three quarters of the known binaries
in the Kuiper
Belt have been discovered with HST, most by our snapshot
surveys. The
statistics derived from this work are beginning to yield
surprising and
unexpected results. We have found a strong concentration
of binaries
among low-inclination Classicals, a possible size cutoff
to binaries
among the Centaurs, an apparent preference for nearly
equal mass
binaries, and a strong increase in the number of binaries
at small
separations. We propose to continue this successful
program in Cycle 16;
we expect to discover at least 13 new binary systems,
targeted to
subgroups where these discoveries can have the greatest
impact.
WFPC2 11544
The Dynamical Legacy of Star Formation
We propose to use WFPC2 to conduct a wide-field imaging
survey of the
young cluster IC348. This program, in combination with
archival HST
observations, will allow us to measure precise proper
motions for
individual cluster members, characterizing the
intra-cluster velocity
dispersion and directly studying the dynamical signatures
of star
formation and early cluster evolution. Our projected
astrometric
precision (~1 mas in each epoch) will allow us to
calculate individual
stellar velocities to unprecedented precision (<0.5
mas/yr; <1 km/s) and
directly relate these velocities to observed spatial
substructure within
the cluster. This survey will also allow us to probe
small-scale star
formation physics by searching for high-velocity stars
ejected from
decaying multiple systems, expanding our knowledge of
multiplicity in
dense environments, and identifying new substellar and
planetary-mass
cluster members based on kinematic membership tests.
WFPC2 11795
WFPC2 Cycle 16 UV Earth Flats
Monitor flat field stability. This proposal obtains
sequences of earth
streak flats to improve the quality of pipeline flat
fields for the
WFPC2 UV filter set. These Earth flats will complement the
UV earth flat
data obtained during cycles 8-15.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS: (None)
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
08
08
FGS REacq
07
07
OBAD with Maneuver
30
30
SIGNIFICANT EVENTS: (None)