DAILY REPORT    #4974

PERIOD COVERED: 5am November 17 - 5am November 18, 2009 (DOY 321/10:00z-322/10:00z)

OBSERVATIONS SCHEDULED

ACS/WFC 11735

The LSD Project: Dynamics, Merging and Stellar Populations of a Sample
of Well-studied LBGs at z~3

A large observational effort with the ground-based ESO/VLT telescopes
allowed us to obtain deep, spatially-resolved, near-IR spectra of
complete sample of 11 Lyman-Break Galaxies at z~3.1. These
observations were used to obtain, for the first time, the metallicity
and the dynamical properties of a sample of objects that, albeit
small, is representative of the total population of the LBGs. We
propose to use HST to obtain high-resolution optical and near-IR
images of this sample of LBGs in order to study the broad-band
morphology and the stellar light distribution of these galaxies. These
images, exploiting the superior spatial resolution of HST images and
the low-background : 1- will allow a precise measure of the dynamical
mass from the velocity field derived with spectroscopy; 2- will permit
a comparison of the distribution of star formation (from the line
emission) with the underlying stellar population, and, 3- will be used
to check if the complex velocity field and the multiple line-emitting
regions detected in most targets can be ascribed to on-going mergers.
This accurate study will shed light on a number of unsolved problems
still affecting the knowledge of the LBGs.

COS/NUV 11900

NUV Internal/External Wavelength Scale Monitor

This program monitors the offsets between the wavelength scale set by
the internal wavecal versus that defined by absorption lines in
external targets. This is accomplished by observing two external
radial velocity standard targets: HD187691 with G225M and G285M and
HD6655 with G285M and G230L. The two standard targets have little flux
in the wavelength range covered by G185M and so Feige 48 (sdO) is
observed with this grating. Both Feige 48 and HD6655 are also observed
in SMOV. The cenwaves observed in this program are a subset of the
ones used during Cycle 17. Observing all cenwaves would require a
considerably larger number of orbits. Constraints on scheduling of
each target are placed so that each target is observed once every ~2-3
months. Observing the three targets every month would also require a
considerably larger number of orbits.

FGS 11788

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.

STIS/CCD 11844

CCD Dark Monitor Part 1

The purpose of this proposal is to monitor the darks for the STIS CCD.

STIS/CCD 11846

CCD Bias Monitor-Part 1

The purpose of this proposal is to monitor the bias in the 1x1, 1x2,
2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up
high-S/N superbiases and track the evolution of hot columns.

WFC3/ACS/UVIS/WFC/IR 11360

Star Formation in Nearby Galaxies

Star formation is a fundamental astrophysical process; it controls
phenomena ranging from the evolution of galaxies and nucleosynthesis
to the origins of planetary systems and abodes for life. The WFC3,
optimized at both UV and IR wavelengths and equipped with an extensive
array of narrow-band filters, brings unique capabilities to this area
of study. The WFC3 Scientific Oversight Committee (SOC) proposes an
integrated program on star formation in the nearby universe which will
fully exploit these new abilities. Our targets range from the
well-resolved R136 in 30 Dor in the LMC (the nearest super star
cluster) and M82 (the nearest starbursting galaxy) to about half a
dozen other nearby galaxies that sample a wide range of star-formation
rates and environments. Our program consists of broad band
multiwavelength imaging over the entire range from the UV to the
near-IR, aimed at studying the ages and metallicities of stellar
populations, revealing young stars that are still hidden by dust at
optical wavelengths, and showing the integrated properties of star
clusters. Narrow-band imaging of the same environments will allow us
to measure star-formation rates, gas pressure, chemical abundances,
extinction, and shock morphologies. The primary scientific issues to
be addressed are: (1) What triggers star formation? (2) How do the
properties of star-forming regions vary among different types of
galaxies and environments of different gas densities and compositions?
(3) How do these different environments affect the history of star
formation? (4) Is the stellar initial mass function universal or
determined by local conditions?

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by GOs in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/UV 11589

Hypervelocity Stars as Unique Probes of the Galactic Center and Outer
Halo

We propose to obtain high-resolution images of 11 new hypervelocity
stars in the Galactic halo in order to establish the first-epoch
astrometric frame, as a part of a long-term program to measure precise
proper motions in an absolute inertial frame. The origin of these
recently discovered stars with extremely large positive radial
velocities, in excess of the escape speed from the Galaxy, is
consistent only with being ejected from the deep potential well of the
massive black hole at the Galactic center. Reconstructing the full
three-dimensional space motion of the hypervelocity stars, through
astrometric proper motions, provides a unique opportunity to measure
the shape and orientation of the triaxial dark matter halo. The
hypervelocity stars allow determination of the Galactic potential out
to 120 kpc, independently of and at larger distances than is afforded
by tidal streams of satellite galaxies such as the Sagittarius dSph
galaxy. Proper motions of the full set of hypervelocity stars will
provide unique constraints on massive star formation in the
environment of the Galactic center and on the history of stellar
ejection by the supermassive black hole. We request one orbit with
WFC3 for each of the 11 hypervelocity stars to establish their current
positions relative to background galaxies. We request a repeated
observation of these stars in Cycle 19, which will conclusively
measure the astrometric proper motions.

WFC3/UVIS 11565

A Search for Astrometric Companions to Very Low-Mass, Population II
Stars

We propose to carry out a Snapshot search for astrometric companions
in a subsample of very low-mass, halo subdwarfs identified within 120
parsecs of the Sun. These ultra-cool M subdwarfs are local
representatives of the lowest-mass H burning objects from the Galactic
Population II. The expected 3-4 astrometric doubles that will be
discovered will be invaluable in that they will be the first systems
from which gravitational masses of metal-poor stars at the bottom of
the main sequence can be directly measured.

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set
of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K
subarray biases are acquired at less frequent intervals throughout the
cycle to support subarray science observations. The internals from
this proposal, along with those from the anneal procedure (Proposal
11909), will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

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                  10             10
FGS REAcq                  05             05
OBAD with Maneuver         10             10

SIGNIFICANT EVENTS: (None)