Daily Rpt #4980

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4980

PERIOD COVERED: 5am November 25 - 5am November 27, 2009 (DOY 329/10:00z-331/10:00z)

OBSERVATIONS SCHEDULED

WFC3/IR 11926

IR Zero Points

We will measure and monitor the zeropoints through the IR filters
using observations of the white dwarf standard stars, GD153, GD71 and
GD191B2B and the solar analog standard star, P330E. Data will be taken
monthly during Cycle 17. Observations of the star cluster, NGC 104,
are made twice to check color transformations. We expect an accuracy
of 2% in the wide filter zeropoints relative to the HST photometric
system, and 5% in the medium- and narrow-band filters.

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the
UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially found via an unexpected bowtie-shaped feature in flatfield
ratios, subsequent lab tests on similar e2v devices have since shown
that it is also present as simply an overall offset across the entire
CCD, i.e., a QE offset without any discernable pattern. These lab
tests have further revealed that overexposing the detector to count
levels several times full well fills the traps and effectively
neutralizes the bowtie. Each visit in this proposal acquires a set of
three 3x3 binned internal flatfields: the first unsaturated image will
be used to detect any bowtie, the second, highly exposed image will
neutralize the bowtie if it is present, and the final image will allow
for verification that the bowtie is gone.

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).

ACS/WFC3 11882

CCD Hot Pixel Annealing

All the data for this program is acquired using internal targets
(lamps) only, so all of the exposures should be taken during Earth
occultation time (but not during SAA passages). This program emulates
the ACS pre-flight ground calibration and post launch SMOV testing
(program 8948), so that results from each epoch can be directly
compared. Extended Pixel Edge Response (EPER) and First Pixel Response
(FPR) data will be obtained over a range of signal levels for the Wide
Field Channel (WFC). The High Resolution Channel (HRC) visits have
been removed since it could not be repaired during SM4.

ACS/WFC3 11879

CCD Daily Monitor (Part 1)

This program comprises basic tests for measuring the read noise and
dark current of the ACS WFC and for tracking the growth of hot pixels.
The recorded frames are used to create bias and dark reference images
for science data reduction and calibration. This program will be
executed four days per week (Mon, Wed, Fri, Sun) for the duration of
Cycle 17. To facilitate scheduling, this program is split into three
proposals. This proposal covers 352 orbits (22 weeks) from 31 August
2009 to 31 January 2010.

FGS 11874

Monitoring FGS2R2 S-Curves after SMOV4

This proposal satisfies the near-term requirement associated with
SMOV4 activity OTA/FGS-10, as well as the long term Cycle 17
requirement to monitor the post SM4 evolution of the FGS2R2 S-curves
stability during its first year on orbit. The S curves will be
obtained from Trans mode observations of stars (point sources) at
several locations in the FGS2R2 FOV in order to monitor both global
and differential (i.e., field-dependent) changes. At each location,
both F583W and PUPIL S-curves will be obtained. Stars in the M35
cluster will be used for this proposal since the field lies very near
the ecliptic and can therefore be observed by HST at two Orients from
August to May.

STIS/CCD/MA1/MA2 11866

Echelle Grating Blaze Function Zero Points

We will observe the flux standard G191B2B, obtaining echelle spectra
in all primary and intermediate wavelength settings. While this was
done in cycle 10 (8915), the echelle blaze shift has proved to depend
sensitively on side of operation, time and the exact MSM positioning.
We therefore believe it is important to obtain a complete set of post-
repair data at default MSM position to allow a comprehensive solution
for the echelle blaze shifts on a repaired side 2.

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.

STIS/CCD 11844

CCD Dark Monitor Part 1

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

WFC3/ACS/UVIS 11724

Direct Age Determination of the Local Group dE Galaxies NGC 147 and
NGC 185

The origin of dwarf elliptical (dE) galaxies remains a mystery and the
dE galaxies of the Local Group provide the best opportunity to study
this galaxy class in detail. We propose to obtain ACS photometry of
main sequence turnoff stars in the M31 dE satellites NGC 147 and NGC
185. Because these galaxies have little to no stars younger than 1
Gyr, resolving the main sequence turnoff is required to directly
quantify their star formation histories. NGC 147 and NGC 185 are the
only two dEs for which a clean measurement is feasible with the HST.
This proposal was accepted in Cycle 15, but little data were taken
before the failure of ACS. The main sequence turnoffs of NGC 147 and
NGC 185 are expected to be at an apparent magnitude of V=29; we
request F606W/F814W imaging one half magnitude fainter than this limit
(three magnitudes fainter than the deepest previous dE observations).
Quantifying the ratio of old to intermediate-age stars will allow us
to discriminate between competing models of dE formation. On-going
Keck/DEIMOS spectroscopy of several hundred red giant stars in each of
these two dE galaxies, coupled with dynamical modeling and spectral
synthesis, will complement the ACS measurement by providing
information on chemical abundance patterns, dark matter content and
internal dynamics. The proposed ACS data will be the first to directly
quantify the onset and duration of star formation episodes in dE
galaxies, and will thereby form the cornerstone in what promises to be
the most comprehensive study of this class of galaxies.

COS/NUV 11720

Detailed Analysis of Carbon Atmosphere White Dwarfs

We propose to obtain UV spectra for the newly discovered white dwarf
stars with a carbon-dominated atmosphere. Model calculations show that
these stars emit most of their light in the UV part of the
electromagnetic spectrum and that an accurate determination of the
flux in this region is crucial for an accurate determination of the
atmospheric parameters. It will also provide a unique opportunity to
test the atomic data and broadening theory in stellar conditions never
met before. This will play a primordial role in our path to understand
the origin of these objects as well to obtain a better understanding
of the evolution of stars in general. The principal objective we hope
to achieve with these observations are 1) obtain accurate surface
gravity/mass for these stars, 2) constrain/determine the abundance of
other elements (O, He, Mg, Ne etc.), especially oxygen, 3) verify the
accuracy of the various theoretical atomic data used in the model
calculations, 4) understand the origin and evolution of carbon
atmosphere white dwarfs, in particular whether progenitor stars as
massive as 10.5 solar masses can produce white dwarfs, rather than
supernovae. We propose to observe 5 objects chosen carefully to cover
the range of observed properties among carbon atmosphere white dwarfs
(effective temperature, surface gravity, abundance of hydrogen/helium
and magnetic field).

WFC3/UVIS 11714

Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters

PLanetary nebulae (PNe) in globular clusters (GCs) raise a number of
interesting issues related to stellar and galactic evolution. The
number of PNe known in Milky Way GCs, four, is surprisingly low if one
assumes that all stars pass through a PN stage. However, it is likely
that the remnants of stars now evolving in galactic GCs leave the AGB
so slowly that any ejected nebula dissipates long before the star
becomes hot enough to ionize it. Thus there should not be ANY PNe in
Milky Way GCs--but there are four! It has been suggested that these
Pne are the result of mergers of binary stars within GCs, i.e., that
they are descendants of blue stragglers. The frequency of occurrence
of PNe in external galaxies poses more questions, because it shows a
range of almost an order of magnitude.

I propose a SNAPshot survey aimed at discovering PNe in the GC systems
of Local Group galaxies outside the Milky Way. These clusters, some of
which may be much younger than their counterparts in our galaxy, might
contain many more PNe than those of our own galaxy. I will use the
standard technique of emission-line and continuum imaging, which
easily discloses PNe. This proposal continues a WFPC2 program started
in Cycle 16, but with the more powerful WFC3. As a by-product, the
survey will also produce color-magnitude diagrams for numerous
clusters for the first time, reaching down to the horizontal branch.

FGS 11704

The Ages of Globular Clusters and the Population II Distance Scale

Globular clusters are the oldest objects in the universe whose age can
be accurately determined. The dominant error in globular cluster age
determinations is the uncertain Population II distance scale. We
propose to use FGS 1R to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main sequence stars with [Fe/H] -1.5. This will
determine the absolute magnitude of these stars with accuracies of
0.04 to 0.06mag. This data will be used to determine the distance to
24 metal-poor globular clusters using main sequence fitting. These
distances (with errors of 0.05 mag) will be used to determine the ages
of globular clusters using the luminosity of the subgiant branch as an
age indicator. This will yield absolute ages with an accuracy of 5%,
about a factor of two improvement over current estimates. Coupled with
existing parallaxes for more metal-rich stars, we will be able to
accurately determine the age for globular clusters over a wide range
of metallicities in order to study the early formation history of the
Milky Way and provide an independent estimate of the age of the
universe.

The Hipparcos database contains only 1 star with [Fe/H] -1.4 and an
absolute magnitude error less than 0.18 mag which is suitable for use
in main sequence fitting. Previous attempts at main sequence fitting
to metal-poor globular clusters have had to rely on theoretical
calibrations of the color of the main sequence. Our HST parallax
program will remove this source of possible systematic error and yield
distances to metal- poor globular clusters which are significantly
more accurate than possible with the current parallax data. The HST
parallax data will have errors which are 10 times smaller than the
current parallax data. Using the HST parallaxes, we will obtain main
sequence fitting distances to 11 globular clusters which contain over
500 RR Lyrae stars. This will allow us to calibrate the absolute
magnitude of RR Lyrae stars, a commonly used Population II distance
indicator.

WFC3/IR 11696

Infrared Survey of Star Formation Across Cosmic Time

We propose to use the unique power of WFC3 slitless spectroscopy to
measure the evolution of cosmic star formation from the end of the
reionization epoch at z6 to the close of the galaxy-building era at
z~0.3.Pure parallel observations with the grisms have proven to be
efficient for identifying line emission from galaxies across a broad
range of redshifts. The G102 grism on WFC3 was designed to extend this
capability to search for Ly-alpha emission from the first galaxies.
Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe about 40 deep (4-5 orbit) fields with the combination of G102
and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.

Our primary science goals at the highest redshifts a (1) Detect Lya
in ~100 galaxies with z5.6 and measure the evolution of the Lya
luminosity function, independent of of cosmic variance; 2) Determine
the connection between emission line selected and continuum-break
selected galaxies at these high redshifts, and 3) Search for the
proposed signature of neutral hydrogen absorption at re-ionization. At
intermediate redshifts we will (4) Detect more than 1000 galaxies in
Halpha at 0.5z1.8 to measure the evolution of the
extinction-corrected star formation density across the peak epoch of
star formation. This is over an order-of-magnitude improvement in the
current statistics, from the NICMOS Parallel grism survey. (5) Trace
``cosmic downsizing" from 0.5z2.2; and (6) Estimate the evolution in
reddening and metallicty in star-forming galaxies and measure the
evolution of the Seyfert population. For hundreds of spectra we will
be able to measure one or even two line pair ratios -- in particular,
the Balmer decrement and [OII]/[OIII] are sensitive to gas reddening
and metallicity. As a bonus, the G102 grism offers the possibility of
detecting Lya emission at z=7-8.8.

To identify single-line Lya emitters, we will exploit the wide
0.8--1.9um wavelength coverage of the combined G102+G141 spectra. All
[OII] and [OIII] interlopers detected in G102 will be reliably
separated from true LAEs by the detection of at least one strong line
in the G141 spectrum, without the need for any ancillary data. We
waive all proprietary rights to our data and will make high-level data
products available through the ST/ECF.

STIS/CCD/MA1/MA2 11690

EG And: Providing the Missing Link Required for Modeling Red Giant
Mass-Loss

For the majority of red giant stars, the basic mass-loss processes at
work are unknown. Indeed, for stars of spectral types between K0 III
and M5-M6 III, much remains unknown about the regions above the
visible photosphere and the transportation of the processed material
outwards to the ISM. Eclipsing symbiotic binary systems, consisting of
an evolved giant in orbit with a white dwarf, provide an opportunity
to take advantage of the finite size of the hot component to probe
different levels of the chromosphere and wind acceleration region in
absorption. This provides spatially resolved thermal, ionization and
dynamic information on the wind which can then be compared against
predictions of hydrodynamical stellar atmosphere codes. The symbiotic
binary EG And can be considered as a Rosetta Stone for understanding
the winds of these objects. The system is ideal on a number of counts
for utilizing the ultraviolet eclipse of the white dwarf (WD)
component to probe, layer-by-layer, the thermal and dynamic conditions
at the very base of the wind and chromosphere of the RG. This
information is vital for constraining, testing and calibrating the new
generation of cool giant wind+chromosphere models and is not possible
to obtain for isolated RGs. This team has studied the UV eclipses of
this system in depth and detail, however in order to definitively
constrain the wind acceleration profile and identify the location of
the temperature rise just above the photosphere, we require 4 STIS
E140M observations of EG And at specific orbital phases. We are also
requesting a E230M observation of an isolated spectral standard,
corresponding to the RG in the binary, which will help place the EG
And results into the context of the general RG population from
analysis of the MgII wind diagnostic lines.

WFC3/UVIS 11661

The Black Hole Mass - Bulge Luminosity Relationship for the Nearest
Reverberation- Mapped AGNs

We propose to obtain WFC3 host galaxy images of the eight nearest AGNs
with masses from reverberation mapping, and one star as a PSF model.
These images will allow us to determine with unprecedented accuracy
the bulge luminosities of the host galaxies, a goal which is not
achievable from the ground due to the blurring of the very bright PSF
component under typical, and even very good, seeing conditions.
High-resolution ACS images of the host galaxies of more luminous AGNs
reveal that the black hole mass- bulge luminosity and black hole
mass-bulge mass relationships for AGNs are not well constrained and
arise from what appear to be fundamentally flawed data sets. With the
addition of the images proposed here to our current sample of ACS
images, we will be able to extend our determinations of the black hole
mass-bulge luminosity and black hole mass-bulge mass relationships for
AGNs by an order of magnitude and test our preliminary results for
these fundamentally important relationships against those previously
determined for quiescent galaxies.

WFC3/ACS/UVIS 11603

A Comprehensive Study of Dust Formation in Type II Supernovae with
HST, Spitzer, and Gemini

The recent discovery of three extremely bright Type II SNe, (2007it,
2007oc, 2007od) gives us a unique opportunity to combine observations
with HST, Spitzer, and Gemini to study the little understood dust
formation process in Type II SNe. Priority 1 Spitzer Cycle 5 and band
1 Gemini 2008A time has already been approved for this project. Since
late-time Type II SNe are faint and tend to be in crowded fields, we
need the high sensitivity and high spatial resolution of ACS and
NICMOS/NIC2 for these observations. This project is motivated by the
recent detection of large amounts of dust in high redshift galaxies.
The dust in these high-z galaxies must come from young, massive stars
so Type II SNe could be potential sources. The mechanism and the
efficiency of dust condensation in Type II SN ejecta are not well
understood, largely due to the lack of observational data. We plan to
produce a unique dataset, combining spectroscopy and imaging in the
visible, near- and mid-IR covering the key phase, 400- 700 days after
maximum when dust is known to form in the SN ejecta. Therefore, we are
proposing for coordinated HST/NOAO observations (HST ACS, NICMOS/NIC2
& Gemini/GMOS and TReCS) which will be combined with our Spitzer Cycle
5 data to study these new bright SNe. The results of this program will
place strong constraints on the formation of dust seen in young high
redshift (z5) galaxies.

ACS/WFC3 11599

Distances of Planetary Nebulae from SNAPshots of Resolved Companions

Reliable distances to individual planetary nebulae (PNe) in the Milky
Way are needed to advance our understanding of their spatial
distribution, birthrates, influence on galactic chemistry, and the
luminosities and evolutionary states of their central stars (CSPN).
Few PNe have good distances, however. One of the best ways to remedy
this problem is to find resolved physical companions to the CSPN and
measure their distances by photometric main-sequence fitting. We have
previously used HST to identify and measure probable companions to 10
CSPN, based on angular separations and statistical arguments only. We
now propose to use HST to re-observe 48 PNe from that program for
which additional companions are possibly present. We then can use the
added criterion of common proper motion to confirm our original
candidate companions and identify new ones in cases that could not
confidently be studied before. We will image the region around each
CSPN in the V and I bands, and in some cases in the B band. Field
stars that appear close to the CSPN by chance will be revealed by
their relative proper motion during the 13+ years since our original
survey, leaving only genuine physical companions in our improved and
enlarged sample. This study will increase the number of Galactic PNe
with reliable distances by 50 percent and improve the distances to Pne
with previously known companions.

WFC3/UVIS 11594

A WFC3 Grism Survey for Lyman Limit Absorption at z=2

We propose to conduct a spectroscopic survey of Lyman limit absorbers
at redshifts 1.8 z 2.5, using WFC3 and the G280 grism. This
proposal intends to complete an approved Cycle 15 SNAP program
(10878), which was cut short due to the ACS failure. We have selected
64 quasars at 2.3 z 2.6 from the Sloan Digital Sky Survey
Spectroscopic Quasar Sample, for which no BAL signature is found at
the QSO redshift and no strong metal absorption lines are present at z
2.3 along the lines of sight. The survey has three main
observational goals. First, we will determine the redshift frequency
dn/dz of the LLS over the column density range 16.0 log(NHI) 20.3
cm^-2. Second, we will measure the column density frequency
distribution f(N) for the partial Lyman limit systems (PLLS) over the
column density range 16.0 log(NHI) 17.5 cm^-2. Third, we will
identify those sightlines which could provide a measurement of the
primordial D/H ratio. By carrying out this survey, we can also help
place meaningful constraints on two key quantities of cosmological
relevance. First, we will estimate the amount of metals in the LLS
using the f(N), and ground based observations of metal line
transitions. Second, by determining f(N) of the PLLS, we can constrain
the amplitude of the ionizing UV background at z~2 to a greater
precision. This survey is ideal for a snapshot observing program,
because the on-object integration times are all well below 30 minutes,
and follow-up observations from the ground require minimal telescope
time due to the QSO sample being bright.

WFC3/UVIS 11588

Galaxy-Scale Strong Lenses from the CFHTLS Survey

We aim to investigate the origin and evolution of early-type galaxies
using gravitational lensing, modeling the mass profiles of objects
over a wide range of redshifts. The low redshift (z = 0.2) sample is
already in place following the successful HST SLACS survey; we now
propose to build up and analyze a sample of comparable size (~50
systems) at high redshift (0.4 z 0.9) using HST WFC3 Snapshot
observations of lens systems identified by the SL2S collaboration in
the CFHT legacy survey.

ACS/SBC/COS/NUV/FUV 11579

The Difference Between Neutral- and Ionized-Gas Metal Abundances in
Local Star- Forming Galaxies with COS

The metallicity of galaxies and its evolution with redshift is of
paramount importance for understanding galaxy formation. Abundances in
the interstellar medium (ISM) are typically determined using
emission-line spectroscopy of HII regions. However, since HII regions
are associated with recent SF they may not have abundances typical for
the galaxy as a whole. This is true in particular for star-forming
galaxies (SFGs), in which the bulk of the metals may be contained in
the neutral gas. It is therefore important to directly probe the metal
abundances in the neutral gas. This can be done using absorption lines
in the Far UV. We have developed techniques to do this in SFGs, where
the absorption is measured for sightlines toward bright SF regions
within the galaxy itself. We have successfully applied this technique
to a sample of galaxies observed with FUSE. The results have been very
promising, suggesting in I Zw 18 that abundances in the neutral gas
may be up to 0.5 dex lower than in the ionized gas. However, the
interpretation of the FUSE data is complicated by the very large FUSE
aperture (30 arcsec), the modest S/N, and the limited selection of
species available in the FUSE bandpass. The advent of COS on HST now
allows a significant advance in all of these areas. We will therefore
obtain absorption line spectroscopy with G130M in the same sample for
which we already have crude constraints from FUSE. We will obtain
ACS/SBC images to select the few optimal sightlines to target in each
galaxy. The results will be interpreted through line-profile fitting
to determine the metal abundances constrained by the available lines.
The results will provide important new insights into the metallicities
of galaxies, and into outstanding problems at high redshift such as
the observed offset between the metallicities of Lyman Break Galaxies
and Damped Lyman Alpha systems.

NIC2/WFC3/IR 11548

Infrared Imaging of Protostars in the Orion A Cloud: The Role of
Environment in Star Formation

We propose NICMOS and WFC3/IR 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.

STIS/CCD/MA1 11525

COS-GTO: STIS High Resolution Observations of the Local ISM

We shall use bright early-type B stars located within 150pc of the Sun
to probe the absorption properties of the interstellar gas associated
with the local cavity. By utilizing the high sensitivity and high
spectral resolution of the HST-STIS spectrograph we shall be able to
place new detection limits on absorption occurring in any highly
ionized gas associated with the lines of NV, SiIV and CIV that may be
present along these sight-lines within the local cavity. These data
will be used to test current theoretical models that generally predict
far higher absorption column densities than have been previously
found. Also, the high spectral resolution will enable far stricter
limits to be placed on the thermal widths of such highly ionized
absorption lines, which previous observations towards the Loop I
region have suggested anomalously narrow profiles consistent with
their formation by either photo ionization or highly non-equilibrium
processes.

WFC3/UVIS/IR 11723

Imaging the Crab Nebula-Like Supernova Remnant 3C 58

The Galactic supernova remnant 3C 58 shares several important
properties with the Crab Nebula. It possesses a young, rapidly
spinning pulsar and an associated compact optical/IR synchrotron wind
nebula. This makes 3C 58, along with the Crab and PSR B0540-69 in the
LMC, only the third such PWN detected in the optical and IR. Also like
the Crab, 3C58 has been associated with a historically reported `guest
star', in this case, the apparent SN of 1181 CE. Its optical
nebulosity contains an unusually large fraction of shocked
circumstellar material, with the remnant's high-velocity, N-rich
ejecta knots exhibiting a strong bi-polar expansion asymmetry.

Despite having a relatively extensive optical nebula, it is the only
young and nearby Galactic SNR that has not yet been imaged by HST.
However, some recent deep, high- resolution Gemini images show a
surprising amount of fine-scale filament detail, revealing some
peculiar optical emission morphologies. Here we propose a WFC3 imaging
survey of 3C 58 in order to investigate: 1) the optical luminosity and
emission efficiency of the remnant's young, 65.7 ms pulsar PSR
J0205+6449 thereby providing a rare testing of pulsar emission models,
2) the effect of the remnant's expanding synchrotron nebula on the
formation of Rayleigh-Taylor instabilities in its optical filaments
like that observed so far only in the Crab through HST imaging, and 3)
the fine-scale structure of 3C 58's slow moving circumstellar and
high-velocity SN ejecta and the morphological and distribution
differences between them.

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 a (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/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.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS:

#12103 REAcq(1,2,1) @11:30:07z, REAcq(1,2,1) @329/13:06:04z and
REAcq(1,2,1) @329/14:42:00z failed because FGS Sequential Attitude
errors were too large to correct

Observations affected: STIS #30-40, Proposal #11866

#12106 REAcq(1,2,1) @330/00:39:06z required 2 attempts to achieve
FL-DV @330/00:41z

Observations possibly affected: STIS #41-44 Proposal #11846, WFC3
#91-94 Proposal #11548

#12108 GSAcq(1,2,1) @331/02:40z & REAcq(1,2,1) @331/03:56:24z during
LOS resulted in FL backup on FGS1

Observations possibly affected: STIS #60 Proposal #11846, ACS #60-61
Proposal #11879, WFC3 #114-117 Proposal #11723.

HSTARS for DOYs 321 & 324 from previous Daily Reports:

#12104 DOY 321 OTA SE review of PTAS data revealed that GSAcq(2,3,3)
@321/04:25:25 failed with search radius limit exceeded on FGS2

Observations affected: WFC3 #47 Proposal #11360

#12105 DOY 324 OTA SE review of PTAS processing shows that
GSAcq(2,1,2) @324/09:08:48z required 3 attempts to achieve CT-DV in
FGS2

Observations possibly affected: WFC3 #156 Proposal #11565

COMPLETED OPS REQUEST:

#18767-0 Realtime OBAD with and without correction @ 329/13:30z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 20 20
FGS REAcq 14 11
OBAD with Maneuver 15 15

SIGNIFICANT EVENTS: (None)