Status Report

NASA Hubble Space Telescope Daily Report # 3623

By SpaceRef Editor
June 1, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




ACS/HRC 9974

Mid-Ultraviolet Spectral Templates for Old Stellar Systems

We propose a three-year program to provide both observational and
theoretical mid-ultraviolet {2300A — 3100A} spectral templates for
interpreting the age and metallicity of globular clusters and
elliptical galaxies from spectra of their integrated light. The mid-UV
is the region most directly influenced by stellar age, and is observed
directly in optical and infrared studies of high-redshift quiescent
systems. The reliability of age and metallicity determinations remains
questionable until non-solar metallicities and abundance ratios are
considered, and stars spanning the color-magnitude diagram are
included, as we propose here. With archival HST STIS spectra we have
improved the list of mid-UV atomic line parameters, then calculated
spectra from first principles which match observed spectra of standard
stars up to one- fourth solar metallicity. We will extend both
observations and calculations to stars of solar metallicity and
beyond, and to those in short-lived stages hotter than the
main-sequence turnoff, stars not currently well-represented in
empirical libraries. The necessary line-list improvements will come
from new high-resolution mid-UV spectra of nine field stars. A key
application of the results of this program will be to the old systems
now being discovered as `Extremely Red Objects’ at high redshifts.
Reliable age-dating of these places constraints on the epoch when
large structures first formed in the universe.


Physical Parameters of the Erupting Luminous Blue Variable NGC 2363-V1

In 1996, we reported the discovery of a bright variable star in the
giant extragalactic H , ii region NGC 2363. Subsequent photometry and
high quality HST/STIS spectroscopy of this star, NGC 2363-V1, revealed
that we are witnessing a significant event in the evolution of a
massive star, namely a major eruption of a Luminous Blue Variable
{LBV}. A quantitative analysis of the STIS datasets gathered in 1997
and 1999 allowed us to determine the luminosity, mass loss rate, wind
terminal velocity, surface temperature and even Fe content of this
erupting LBV. Because such events are rare, continuous monitoring of
the physical parameters of NGC 2363- V1 over the course of its present
eruption will provide an invaluable set of constraints for theoretical
models. We therefore propose to obtain high quality STIS spectra of
this star once a year for the next three observing Cycles.

FGS 9883

Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster
Distances and the Ages of the Oldest Stars

The ages of the oldest stars are a key constraint on the evolution of
our Galaxy, the history of star formation, and cosmological models.
These ages are usually determined from globular clusters. However, it
is alternatively possible to determine ages of extreme Population II
subgiants in the solar neighborhood based on trigonometric parallaxes,
without any recourse to clusters. This approach completely avoids the
vexing issues of cluster distances, reddenings, and chemical
compositions. There are 3 known nearby, extremely metal-deficient Pop
II subgiants with Hipparcos parallax errors of 6-11% which are
available for such age determinations. At present, based on the latest
isochrones, the derived ages of these stars {HD 84937, HD 132475, and
HD 140283} are all close to 14 Gyr, uncomfortably close to or higher
than current estimates of the age of the universe. However, the errors
in the Hipparcos parallaxes imply uncertainties of at least 2 Gyr in
the ages of the 3 stars. We propose to measure parallaxes of these
three Pop II subgiants using HST’s Fine Guidance Sensor 1R. We expect
to reduce the Hipparcos parallax error bars by factors of 5-6,
providing the most stringent test yet of current theoretical stellar
models of Pop II stars and pushing the age uncertainties to below 0.5
Gyr. These data will also provide a major new constraint on the
distance scale of globular clusters, with wide implications for
stellar evolution and the calibration of Pop II standard candles.


AALs in Quasars: Diagnostics of the Environment

Associated absorption lines {AALs} in quasar spectra carry a wealth of
information on the gas-phase kinematics, ionization states, column
densities, outflow masses, and elemental abundances near the quasars.
Most of the existing UV spectra have low spectral resolution, which
hampers efforts to accurately determine these properties at low
redshifts. We propose medium-resolution FUV and NUV STIS spectroscopy,
more than an order of magnitude improvement in spectral resolution
over previous studies, to observe a sample of AAL quasars at redshifts
and luminosities intermediate between the nearby Seyferts and the
bright, high-z quasars. Our aim is to determine basic physical
parameters for the absorbers, measure the abundances, search for AAL
variability, and constrain the location of the absorbers relative to
the central quasars. A unique aspect of our z~0.2 sample is the
ability to get both UV and X-ray diagnostics, thus allowing us to
perform a joint analysis of our STIS data with X-ray observations to
further constrain the full range of ionizations and column densities
of the UV/X-ray absorbing gas.

NIC/NIC3 9865

The NICMOS Parallel Observing Program

We propose to continue managing the NICMOS pure parallel program.
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at
0.7<z<1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial–but poorly observed–redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.


A Search for the Missing Baryons in Nearby Cosmic Filaments

Most of the baryons in the local universe are "missing" in that they
are not in galaxies or in the previously detected gaseous phases.
These missing baryons are predicted to be in a warm-hot low density
phase, largely in the giant cosmic filaments that connect the denser
virialized clusters and groups of galaxies. Models show that the
highest covering fraction of such filaments occurs in superclusters
and observations of two AGNs behind known superclusters showed
multiple LyAlpha absorption systems at the supercluster redshift.
These results are impressive considering that these AGNs were not even
optimally located. Here we selected a several AGNs that lie close to
the expected central axis of supercluster filaments. These HST
observations will identify LyAlpha absorbing gas while a complementary
FUSE program will search for OVI gas in the same systems.


Anomalous Flux Ratios in Quadruple Gravitationally Lensed QSOs

We propose to observe eight {8} gravitationally lensed systems which
exhibit quadruple images of the background high redshift quasars.
Models invoking a smooth potential fit the observed image positions
accurately, in most cases better than 5 milliarcseconds. But the same
models dramatically fail to predict the observed flux ratios. These
anomalous flux ratios can be attributed to micro- or milli-lensing in
the massive lensing halo. In this proposal, we will isolate the source
of the anomalous flux ratios by using the superior resolution of
HST/STIS to obtain spectrophotometric data and compare the emission
line flux ratio of the QSOs to the continuum flux ratios. Due to the
much larger size of the broad emission line regions, the flux ratios
in the emission lines should only be affected by milli-lensing if the
sub-halos are comparable or larger in projected size than the source
region. That is, flux ratios observed in the QSO continuum are
sensitive to substructure on all scales {both micro- and
milli-lensing}, while the broad emission lines are insensitive to
micro-lensing due to the larger physical size of the source emission
region. This sample of eight quasars will provide the definitive
evidence to distinguish between possible sources causing the observed
anomalous flux ratios.


A SNAPSHOT Survey of Sharp-Lined Early B-Type Stars

Although spectrum synthesis studies of the UV spectra of sharp-lined
main sequence B stars provide us with some our best determinations of
the abundances of the Fe group and neutron capture elements and the
chemical evolution in our galaxy and the Magellanic Clouds, the HST
archive is virtually devoid of high resolution spectra of the bright
nearby B stars that have become to be regarded as abundance standards.
For example, there are NO observations of HR 1886, iota Her, and tau
Her, the sharpest-lined representatives {V sin i < 5 km/s} of spectral
classes B1 V, B3 IV-V and B5 IV, and only a few tiny spectral
intervals of gamma Peg {B2 IV}. Information on the abundances of the
Fe group is important for computing opacities for stellar evolution
calculations and for determining astrophysical f-values. There are no
suitable galactic standards in the HST database to compare with recent
HST/STIS observations of B stars in the Magellanic Clouds and the
likely future observations of similar objects in M31 and other nearby
galaxies. To correct this deficiency, we propose SNAPSHOT observations
with the STIS E140M and E230M gratings of 33 of the best bright
abundance standards in nearby clusters and the galactic field. Using
this data we will determine the abundances of the Fe group and heavy
elements using the technique of spectrum synthesis with LTE and NLTE
treatments. We waive the proprietary period.

NIC1/NIC2 9844

Brown dwarf atmospheric variability observations

We propose to use NIC1 and NIC2 to study brown dwarfs for atmospheric
variability. We will observe a sequence of early Ts, a detected
variable T2, a T3 and a T4.5. Atmospheric variability, that is
expected by some models for these objects, would constrain the
physical parameters of cloud vertical distribution, horizontal
homogeneity and the dynamics of the very cool atmospheres. The
existence and amplitude of the variations would reveal the size and
distribution of the cloud cover over the surface of the brown dwarf
and test a model explaining the rapidity of the L to T type
transition. The relative color changes would constrain the vertical
extent of dynamical process and the depth in the atmosphere at which
they take place. If a periodicity is measured, the rotational period
of the dwarf could be estimated. HST provides the unique and crucial
opportunity to observe beyond Earth atmospheric variable absorption,
particularly in the important water bands

ACS/WFC 9821

The Second Parameter Effect in Metal-Rich Globular Clusters: A
Snapshot Study of NGC 6388

While it has long been known that at least one parameter besides the
metallicity, [Fe/H], determines the horizontal branch {HB} morphology
of Galactic globular clusters {GCs}, our ignorance as to the nature of
this second parameter {or parameters} has been a major stumbling block
in understanding the formation history and age of the GC system. The
hot HB populations recently discovered by HST in the metal-rich GCs
NGC 6388 and NGC 6441 provide a unique opportunity for unraveling this
second-parameter effect. Many different theories have been proposed to
explain the pronounced upward slope of the HBs in these GCs, including
stellar rotation, metallicity spread, and a dwarf galaxy origin. We
propose to test these theories by obtaining B, V, I time-series
photometry of the RR Lyrae variables in the core of NGC 6388 in order
to determine whether, as predicted, the pulsation periods are
unusually long due to a high HB luminosity. If confirmed, this would
argue against age or mass loss as the second parameter in NGC 6388
and, more generally, would have implications for the use of RR Lyrae
stars as standard candles for determining GC distances and ages. Light
curves will also be obtained for the crowded Population II Cepheids
near the core of NGC 6388, the most metal-rich GC, along with NGC
6441, known to contain such stars. We waive proprietary rights to any
data obtained.

ACS/WFC 9788

A Narrow-band Snapshot Survey of Nearby Galaxies

We propose to use ACS/WFC to conduct the first comprehensive HST
narrow-band {H-alpha + [N II]} imaging survey of the central regions
of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will
cover, at high angular resolution extending over a large field, an
unprecedented number of galaxies representing many different
environments. It will have important applications for many
astrophysical problems of current interest, and it will be an
invaluable addition to the HST legacy. The observations will be
conducted in snapshot mode, drawing targets from a complete sample of
145 galaxies selected from the Palomar spectroscopic survey of nearby
galaxies. Our group will use the data for two primary applications.
First, we will search for nuclear emission-line disks suitable for
future kinematic measurements with STIS, in order to better constrain
the recently discovered relations between black hole mass and bulge
properties. Preliminary imaging of the type proposed here must be
done, sooner or later, if we are to make progress in this exciting new
field. Second, we will investigate a number of issues related to
extragalactic star formation. Specifically, we will systematically
characterize the properties of H II regions and super star clusters on
all galactic scales, from circumnuclear regions to the large-scale

STIS 9786

The Next Generation Spectral Library

We propose to continue the Cycle 10 snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters. This program is using the
low dispersion UV and optical gratings of STIS. The library will be
roughly equally divided among four metallicities, very low {[Fe/H] lt
-1.5}, low {[Fe/H] -1.5 to -0.5}, near-solar {[Fe/H] -0.3 to 0.1}, and
super-solar {[Fe/H] gt 0.2}, well-sampling the entire HR-diagram in
each bin. Such a library will surpass all extant compilations and have
lasting archival value, well into the Next Generation Space Telescope
era. Because of the universal utility and community-broad nature of
this venture, we waive the entire proprietary period.


Galaxy Evolution in Action : The Detailed Morphology of Post-Starburst

If galaxies evolve morphologically, then some should be in transition
between late and early types. One proposed evolutionary mechanism is a
galaxy-galaxy merger, but evolved merger products are difficult to
find. Fortunately, spectroscopic surveys have now uncovered large
numbers of E+A galaxies, a class of objects whose post-starburst
spectra, current lack of HI gas, and pressure-supported kinematics
suggest that they are the missing panel that connects the "Toomre
sequence" of merging spirals with normal ellipticals and S0s. Our
first HST observations of five of these galaxies are intriguing. We
find a considerable range of tidally disturbed morphologies, an "E+A"
fundamental plane, significant differences among the color gradients
within 1 kpc {~0.8”}, and populations of bright, blue globular
clusters. These initial results are difficult to interpret, however,
because they are drawn from a small sample of galaxies whose very blue
overall colors may have selected a particular evolutionary path of
E+As. Here we propose for ACS imaging of the remaining 15 E+As from
the Las Campanas Redshift Survey to probe the full range of E+A
properties. The proposed observations will allow us to 1} determine
what fraction of the interactions that lead to E+As destroy all
disk-like structures {and therefore necessarily lead to elliptical
formation}, 2} measure the inner color gradients and constrain the
spatial distribution of stars produced as gas sinks to the center
during a merger, and 3} determine whether these interactions produce
globular clusters in the required numbers to account for the increased
specific frequency of clusters in early-type galaxies.


Black Holes in Big Galaxies with Small Bulges

In early-type galaxies the black hole {BH} mass is tightly correlated
with the bulge velocity dispersion. This correlation suggests that the
BH mass is determined by local processes in the central part of the
galaxy. However, the bulge dispersion in these galaxies is correlated
with the disk circular speed which in turn correlates with the
inferred halo circular speed {the "disk-halo conspiracy"}. For this
reason, existing data cannot decide whether the BH mass is set by the
bulge dispersion or the disk or halo circular speed. We propose to
break this degeneracy by weighing the BH in 3 Sc galaxies in which the
ratio of bulge circular speed to bulge velocity dispersion is large,
leading to large differences between BH masses predicted from these
quantities. These measurements will increase the number of carefully
studied Sc bulges from one to four and will determine whether the
masses of nuclear BHs are set by {presumably baryonic} processes in
galaxy bulges or by {presumably non-baryonic} processes in their dark


Galaxy Evolution During Half the Age of the Universe: ACS imaging of
rich galaxy clusters

Detailed studies of nearby galaxies {z<0.05} have shown that galaxies
have very complex histories of formation and evolution involving
mergers, bursts of star formation, and morphological changes. Even so,
the global properties of the galaxies {radii, luminosities, rotation
velocities, velocity dispersions, and absorption line strengths}
follow a number of very tight {empirical} scaling relations, e.g. the
Tully-Fisher relation and the Fundamental Plane. These relations place
constraints on models for galaxy evolution. The results for nearby
galaxies rely on high signal-to-noise spectroscopy and multi-color
photometry. With the Gemini Telescopes and the Hubble Space Telescope
{HST} it is possible to carry out similar detailed studies of galaxies
at much larger redshifts, up to z~1.0, equivalent to half the age of
the Universe. We have started a project using the scaling relations
and aimed at studying the galaxy evolution over the last half of the
age of the Universe. The project is based on a large database of
spectroscopy and photometry of galaxies in 15 X-ray selected clusters
of galaxies with redshifts between 0.15 and 1.0. Spectroscopic
observations are being obtained using both Gemini Telescopes; we have
observed 6 clusters so far, covering from z=0.18 to z=0.83. We propose
to use HST/ACS to image the clusters and determine the morphologies
and measure the sizes of the galaxies. At this time we ask for 26
orbits to image four of the clusters in our sample.


Confirmation of New Candidates for the Study of Intergalactic Helium

The reionization of intergalactic helium is believed to take place
between redshift 3 and 4. The study of HeII Lyman-alpha absorption in
four quasars at 2.7<z<3.3 demonstrates the great potential of such an
intergalactic-medium {IGM} probe and suggests that the reionization
epoch is at higher redshifts. Clean quasar sightlines may be found
only from massive pre-selection processes in the optical and UV,
because of random, severe absorption by intervening Lyman-limit
systems. The SDSS has discovered approximately 36000 quasars, and we
propose to verify the UV detectability in 70 top candidates for helium
studies extending to even higher redshift. Our proposed approach has
already proven successful, and additional positive confirmations will
allow follow-up observations, with STIS, to pinpoint the epoch of
reionization of the IGM, and the evolution of its properties near that

ACS/HRC 9746

Binary systems in the Kuiper Belt

The properties of the orbits of Kuiper belt object {KBO} satellites
hold keys to fundamental insight into masses and densities of KBOs,
the interaction history of the early solar system, the internal
structure of distant ice-rock bodies, and even the genesis of the
Pluto-Charon binary. Within the past 18 months, 9 KBO satellite
systems have been discovered, allowing for the first time the
possibility of characterizing a sample of KBO satellite orbital
properties. We propose HRC observations to determine satellite orbits
in the 6 best cases. We have carefully devised a strategy for each of
these 6 systems to make maximum use of ground-based observations,
previous HST observations, and the smallest possible number of new HST
observations. Our proposed observations will efficiently provide
highly reliable orbital solutions which are critical to achieving the
scientific promise available from the study of these systems. Our
strategy relies heavily on extensive Monte Carlo simulations to define
optimal times of observing such that each new point obtained gives
maximum leverage for refining the orbital solution. We find that with
this strategy we can provide mass solutions for all 6 systems to an
accuracy of better than 10% using only 25 new HST observations. This
highly efficient program provides extreme scientific output with
optimal use of scarce resources.

ACS/WFC 9744

HST Imaging of Gravitational Lenses

Gravitational lenses offer unique opportunities to study cosmology,
dark matter, galactic structure, galaxy evolution and quasar host
galaxies. They are also the only sample of galaxies selected based on
their mass rather than their luminosity or surface brightness. While
gravitational lenses can be discovered with ground-based optical and
radio observations, converting them into astrophysical tools requires
HST. We will obtain ACS/WFC V and I images and NICMOS H images of 21
new lenses never observed by HST and NICMOS H images of 16 lenses
never observed by HST in the IR. As in previous cycles, we request
that the data be made public immediately.


Integrated Absorption- and Emission-Line Analysis of Nebulae

Serious discrepancies have arisen in CNONe abundance determinations
for galactic nebulae in the past ten years depending upon which type
of emission lines are used in the analysis: forbidden vs. permitted
lines. The cause of the discrepancies, which can exceed an order of
magnitude for some PNe, has been studied intensively but is still
unknown. Emission line abundances cannot be considered reliable until
the nature of these contradictory results is understood. We have
developed a technique for integrating absorption lines into emission
analyses for diffuse nebulae that provides an independent check on the
validity of emission-line analyses. It requires high resolution
observations of UV resonance absorption produced by the nebular gas in
imbedded or background stars together with optical spectra of the
nebulae. We propose to obtain UV spectra of four PNe central stars
with STIS that will provide data necessary to exploit the new
technique of integrated abundance determination that combines both
emission and absorption lines.


Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs the most
rigorous test. The case for cosmic acceleration rests on the
observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than
they would be in a universe without acceleration. A powerful and
straightforward way to assess the reliability of the SN Ia measurement
and the conceptual framework of its interpretation is to look for
cosmic deceleration at z > 1. This would be a clear signature of a
mixed dark-matter and dark-energy universe. Systematic errors in the
SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia
peak luminosity would not show this change of sign. We have obtained a
toehold on this putative “epoch of deceleration” with SN 1997ff at z
= 1.7, and 3 more at z > 1 from our Cycle 11 program, all found and
followed by HST. However, this is too important a test to rest on just
a few objects, anyone of which could be subject to a lensed
line-of-sight or misidentification. Here we propose to extend our
measurement with observations of twelve SNe Ia in the range 1.0 < z <
1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be
discovered as a byproduct from proposed Treasury and DD programs.
These objects will provide a much firmer foundation for a conclusion
that touches on important questions of fundamental physics.

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration – CR Persistence Part 3

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.

S/C 4974


No available description

ACS/WFC 10268

Recovery of three faint Kuiper Belt Objects discovered with HST

We propose 6 orbits to make ACS/WFC follow-up observations of three
faint Kuiper Belt Objects {KBOs} that we discovered in the Large Cycle
11 program GO 9433 {G. Bernstein, PI; Bernstein et al. 2004}. These
KBOs are the faintest — and therefore smallest — KBOs known. Two of
these objects can be recovered {and the third easily recovered and its
colors probed} only with HST. Any future studies of small KBOs will
require knowledge of our three faint KBOs. With the proposed
observations, the locations of these KBOs will be known quite well
until after first light for JWST. Without the proposed observations,
these three small KBOs will be effectively lost. This small program
represents a small investment of HST time to solidify the legacy of
the Bernstein et al. Large GO program. With the proposed observations,
we will be able to determine with certainty the dynamical classes of
these three KBOs, testing the hypothesis that small KBOs are
predominantly classical KBOs. We will also test the suggestion that
classical KBOs are uniformly quite red. Lastly, our observations will
enable physical studies {e.g., spectroscopy} with JWST a decade from
now. All these measurements will provide important evidence for
theories on the formation and evolution of the Solar System.

WFPC2 10072


This calibration proposal is the Cycle 12 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
{gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a
monitor for possible buildup of contaminants on the CCD windows.

WFPC2 10070

WFPC2 CYCLE 12 Supplemental Darks Part 2/3

This dark calibration program obtains 3 dark frames every day to
provide data for monitoring and characterizing the evolution of hot

WFPC2 10068

WFPC2 CYCLE 12 Standard Darks

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.


CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
development of hot pixels and test for any source of noise in ACS CCD
detectors. This programme will be executed once a day for the entire
lifetime of ACS.

STIS/MA1 10034

Cycle 12 MAMA Dark Monitor

This test performs the routine monitoring of the MAMA detector dark
noise. This proposal will provide the primary means of checking on
health of the MAMA detectors systems through frequent monitoring of
the background count rate. The purpose is to look for evidence of
change in dark indicative of detector problem developing.

STIS/CCD 10020

CCD Bias Monitor – Part 2

Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1,
and 1×1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.


Focus Monitor

The focus of HST is measured from WFPC2/PC and ACS/HRC images of
stars. Multiple exposures are taken in parallel over an orbit to
determine the influence of breathing on the derived mean focus.
Observations are taken of clusters with suitable orientations to
ensure stars appear in all fields.


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

HSTAR 9432: GS Acquisition (1,2,1) @ 150/08:34:28Z resulted in FL
backup on FGS 2 due to SSLE on FGS 1. Prior FHST FM Updates @
150/08:22:30Z and 08:25:15Z showed good attitude error vector. FHST
Map @ 150/09:17:10Z showed 3-axis (RSS) error value ~ 10.00 arcsec.
GS Reacquisitions @ 150/10:11:38Z and 11:47:35Z also resulted in FL
backup. GS Reacquisition @ 150/11:47:35Z took two attempts to reach
FL due to SSLE on FGS 2. Under investigation.



  • 1115-0 CCC IPCONFIG Connnection 149/11:54z
  • 1241-0 ESTR @ Reconditioning @ 149/23:54z

                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq             38                          38
FGS REacq             35                          35
FHST Update          63                          63


Successfully uplinked the Battery Reconditioning MACRO, Version D @
153/10:17:10Z (OR 17175-2 with attached script). Dumped the SPC Table
(Table 1, which includes the new MACRO) and compared with the Battery
Capacity SPC MACRO load. Zero miscompares and no data missing.

Start Battery 4 Capacity Test scheduled 153/10:10Z (OR 17172 with
attached script). Three opportunities to connect SA Section 4 to
Diode Bus C and their associated discharge terminations are scheduled
to ensure no large trickle discharge in the orbit prior to start of
test. First opportunity 153/11:10Z – 155/08:10Z, second 153/12:37Z –
155/09:37Z, and third 153/14:18Z – 155/11:18Z. The shadow entry of
the first opportunity to start the test is 153/11:01Z.

Solar Arrays have been managed to be near normal during the test
time-frame. The compatible pointing profile covers the time-frame
153/08:32Z – 156/04:45Z.

Continuous Engineering Recording (CER) scheduled 153/09:35Z –
155/17:48Z. In order to receive both engineering and science data
during the test and to avoid data recorder overflows, a number of gaps
in the CER were planned. Efforts were made to match these gaps to the
known times of TDRS return contacts, thereby minimizing the number and
duration of the gaps in the CER. A total of four science data
playbacks and three engineering data playbacks were scheduled during
the CER.

The ESTR is required to record engineering data during the SSR science
and engineering data playbacks. The ESTR data will be played back
only if required (loss of real-time telemetry during SSR playback).
See OR 17174 with attached ESTR Record script for details.

FGS 3 ITS test scheduled 153/07:51:13Z- 07:58:00:09Z. The expected
real-time update to the FGS-2R K16 factor occurs later in this SMS.

SpaceRef staff editor.