Status Report

Hubble Space Telescope Daily Report #3043 – 28 Jan 2002

By SpaceRef Editor
January 28, 2002
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PERIOD COVERED: 0000Z (UTC) 01/25/02 – 0000Z (UTC) 01/28/02

Daily Status Report as of 028/0000Z


1.1 Completed STIS/CCD/MA1 9283 (Probing the Gas in the V471 Tau System
with Absorption Spectroscopy)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
observe the eclipsing dA+K2V binary V471 Tau in order to probe the spatial
extent of the chromosphere/corona of an active dwarf star. Previous HST
observations have shown chromospheric and transition region species {O I
through N V} in absorption at radial extents of up to 2 K star radii on one
side of the star, but not on the other. X-ray observations have revealed
large absorption dips, primarily but not exclusively from gas near the
inner Lagrangian points of the system. Chandra will probe the neutral gas,
by observing the time-variability of the neutral Hydrogen absorption
column, and by observing the variations of the depths of absorption
edges. The white dwarf photosphere provides a bright, soft continuous
spectrum against which to observe these changes. All observations
completed nominally.

1.2 Completed Seven Sets of WF/PC-2 8937 (Cycle 9 Supplemental Darks pt2/3)

The WF/PC-2 was used obtain three dark frames every day to provide
data for monitoring and characterizing the evolution of hot pixels. No
problems were encountered.

1.3 Completed Four Sets of WF/PC-2 8941 (Cycle 10 UV Earthflats)

The WF/PC-2 was used to monitor flat field stability by obtaining
sequences of earth streak flats to improve the quality of pipeline flat
fields for the WFPC2 UV filter set. The proposal had no problems.

1.4 Completed Six Sets of STIS/CCD 8901 (Dark Monitor-Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks. There was no anomalous activity.

1.5 Completed Two Sets of WF/PC-2 9118 (Tracing the Cosmic Expansion to
z>1 with Type Ia Supernovae)

The WF/PC-2 was used to observe type Ia supernovae in order to
provide evidence for an accelerating universe. The case for cosmic
acceleration rests almost entirely on the observation that the observed SN
Ia at z~0.5 are 0.25 magnitudes fainter than expected for a
non-accelerating Universe. It is proposed to follow five SN Ia in the
range 0.95 0 cosmology, this experiment is a powerful and
straightforward way to assess the reliability of the SN Ia
measurements. In addition, if SN Ia are reliable standard candles, the
proposed observations will significantly increase the precision with which
Omega_Lambda and Omega_M are measured. There was no reported anomalous

1.6 Completed Eight Sets of STIS/CCD 9317 (Pure Parallel Imaging
Program: Cycle 10)

The Space Telescope Imaging Spectrograph (CCD) was used to perform
the default archival pure parallel program for STIS during cycle 10. There
were no reported problems.

1.7 Completed Three Sets of STIS/CCD 8903 (Bias Monitor – Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to 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. There were no problems.

1.8 Completed STIS/CCD 9143 (Spectrophotometry of Nearby Seyfert 2
Nuclei: Can We Eliminate the Seyfert 2 Class?)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate Seyfert 2s that are distinguished by the absence of the broad
emission lines characteristic of Seyfert 1s and more luminous QSOs. Are
Seyfert 2s fundamentally different from Seyfert 1s and their brighter
cousins? Or is the broad emission line region in Seyfert 2s simply
suppressed by obscuring material as postulated by the unification
model? If the latter model is correct, the weak broad emission lines in
the Seyfert 2s may simply be overwhelmed by starlight from the
circumnuclear region, particularly in the case of recent star
formation. It is proposed to determine if all Seyfert 2s have {weak} broad
emission line regions by obtaining long-slit STIS spectroscopy for a
well-defined sample of 20 Seyfert 2s {3 archival, 17 new}. The
observations completed with no anomalous activity.

1.9 Completed Fifteen Sets of WF/PC-2 9318 (POMS Test Proposal: WFII
Parallel Archive Proposal Continuation)

The WF/PC-2 was used to perform the generic target version of the
WFPC2 Archival Pure Parallel program. The program was used to take
parallel images of random areas of the sky, following the recommendations
of the Parallels Working Group. There were no reported problems.

1.10 Completed WF/PC-2 9060 (Photometry of a Statistically Significant
Sample of Kuiper Belt Objects)

The WF/PC-2 was used to propel the physical study of KBOs forward
by performing accurate photometry at V, R, and I on a sample of up to 150
KBOs. The sample is made up of objects that will be observed at thermal
infrared wavelengths by SIRTF and will be used with those data to derive
the first accurate diameters and albedos for a large sample of KBOs. The
observations completed nominally.

1.11 Completed STIS/CCD/MA2 9161 (The Ultraviolet Properties of
Obscured QSOs)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe a subset of The Two Micron All-Sky Survey {2MASS} -discovered QSOs
to: 1} determine if UV absorption- line features are present as seen in
several other highly polarized AGN populations; 2} test relationships
between X-ray and UV/optical attenuation, AGN spectral type, optical
polarization, and detected UV absorption-line features; and 3} characterize
the spectral energy distributions and UV properties of obscured
QSOs. There were no problems.

1.12 Completed STIS/CCD/MA2 9048 (Boron Constraints on Slow Mixing in
Low Mass Stars)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe the atomic and nuclear characteristics of the light elements Li, Be
and B, that make their photospheric abundances ideal tracers of internal
physical processes in stars. Both Li and Be have been heavily utilized to
this end since their diminished abundances are a direct result of the
extent of internal slow mixing between surface and interior layers, as has
been shown with ground-based data. Boron provides a fresh and special
probe because it survives to greater depths inside stars than does Li or
Be, and can thus uniquely reveal the depth of mixing. It is proposed to
observe B in stars with very large depletions of Li and Be, i.e. stars
which have been the most seriously affected by mixing. No problems occurred.

1.13 Completed Two Sets of STIS/MA2 9573 (NUV-MAMA Daily Dark Monitor)

The Space Telescope Imaging Spectrograph (MA2) was used to perform
daily monitoring of the NUV MAMA detector dark noise in order to monitor
the effects of thermal changes on the NUV dark rate. No problems occurred.

1.14 Completed Five Sets of STIS/CCD 9037 (Imaging the Dust Disk around
Epsilon Eridani)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
Epsilon Eridani, the closest star to the Sun, around which a planet has
been discovered. An asymmetric dust disk around the star has been detected
in sub-millimeter observations. The observations completed with no
reported problems.

1.15 Completed Two Sets of STIS/CCD 9066 (Closing in on the Hydrogen
Reionization Edge of the Universe)

The Space Telescope Imaging Spectrograph (CCD) was used in parallel
constrain the Hydrogen reionization edge in emission that marks the
transition from a neutral to a fully ionized IGM at a predicted
redshifts. The proposal completed uneventfully.

1.16 Completed WF/PC-2 9141 (Fine Scale Temperature Fluctuations in
Gaseous Nebulae)

The WF/PC-2 was used to image the Orion and Eskimo nebulae in
filter sets that will allow determination of O III 5007 and 4363 Angstrom
flux ratios, which is a well calibrated electron temperature
determinant. All observations were completed without incident.

1.17 Completed WF/PC-2 8932 (Decontaminations and Associated
Observations Pt. 1/3)

The WF/PC-2 was used for the monthly WFPC2 decons. Also included
are instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post-decon internals {bias, intflats, kspots, &and
darks}, UV throughput check, VISFLAT sweep, and internal UV flat check. No
problems were reported.

1.18 Completed Two Sets of STIS/CCD 9088 (Next Generation Spectral
Library of Stars)

The Space Telescope Imaging Spectrograph (CCD) was used to produce
a “Next Generation” Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters by using the low dispersion UV
and optical gratings of STIS. The library will be roughly equally divided
among four metallicities, very low {Fe/H < -1.5}, low {-1.5 < Fe/H < -0.5}, near-solar {-0.5 < Fe/H < 0.1}, and super-solar {Fe/H > 0.1}, 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. No problems occurred.

1.19 Completed FGS/1 9168 (The Distances to AM CVn Stars)

Fine Guidance Sensor (FGS) #1 was used to determine the parallaxes
and proper motions of the five brightest of the seven known AM CVn
systems. AM CVn systems are binaries where mass is transferred from a
completely hydrogen-deficient, degenerate mass donor to a white dwarf
primary through a helium accretion disk. A better understanding of these
systems is crucial for a number of reasons: (1) to study the late stages of
binary evolution, (2) to study the effect of chemical composition on the
physics of accretion discs, (3) to estimate their contribution to the
Supernovae Ia rate, and (4) to estimate their contribution to the
gravitational radiation background. All observations completed with no
reported problems.

1.20 Completed STIS/CCD 9128 (A Snapshot Survey of Absorption Lines
from High Velocity Clouds in the Milky Way)

The Space Telescope Imaging Spectrograph (CCD) was used to search
for Mg II and Mg I absorption from Galactic High Velocity Clouds {HVCs}
along the sightlines of 51 of the brightest QSOs, BL Lacs and Seyfert 2
galaxies in the sky. The observations completed with no reported problems.

1.21 Completed STIS/CCD 9107 (The Fundamental Plane for Nuclear Black

The Space Telescope Imaging Spectrograph (CCD) was used to conduct
more in-depth searches for supermassive black holes in galaxy
centers. Previous work has led to the discoveries that {1} most or all hot
galaxies contain massive dark objects at their centers, presumably black
holes; {2} there is a remarkably tight correlation between the black-hole
mass and the luminosity-weighted velocity dispersion of the hot component
of the galaxy. This mbh-Sigma relation has a scatter which is <0.3 dex in mbh and consistent with zero. This relationship suggests a strong link between black-hole formation, AGN activity, and galaxy formation, and once it is understood this link should advance our understanding of all three processes. The goal of this proposal is to investigate the scatter in the mbh-Sigma relation and the role of possible second parameters, by examining a sample of galaxies at fixed velocity dispersion Sigma=200+/- 20 kms. This approach decouples the effects of a second parameter from uncertainties in the shape of the mbh-Sigma relation, and minimizes spurious correlations because all of the galaxies will be studied using the same well-tested observational and modeling techniques. No anomalous activity occurred.

1.22 Completed FGS/1 9183 (Completing the Astrometric Orbit for a Pair
of Pre-Main Sequence Low-Mass Stars)

Fine Guidance Sensor #1 was used to resolve a visual binary that is
part of the closest system of pre-main sequence stars, HD 98800. This
system is 50 pc away and this binary has a period just under a year,
meaning the separation is about 20 milliarcsec. The two stars have similar
brightnesses. The goal is to determine an astrometric orbit which, when
combined with radial velocity observations, leads to the first
dynamically-determined masses for low-mass pre-main sequence stars. All
observations completed normally.

1.23 Completed WF/PC-2 8942 (Cycle 10 Intflat Sweeps and Linearity Test)

The WF/PC-2 was used to monitor the pixel-to-pixel flatfield
response and provide a linearity check. These intflat sequences are done
once during the year and the images will provide a backup database in the
event of complete failure of the visflat lamp as well as allow monitoring
of the gain ratios. There were no reported problems.

1.24 Completed FGS/1 9034 (The Masses and Luminosities of Population II

Fine Guidance Sensor #1 was used to observe the mass-luminosity
relation {MLR} of Population II stars of which very little is currently
known. With the advent of the Hipparcos Catalogue, improved distances to
many spectroscopic binaries known to be Pop II systems are now
available. After surveying the literature and making reasonable estimates
of the secondary masses, we find 13 systems whose minimum separation should
be larger than the resolution limit of FGS #1. The observations completed


2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 25

Successful: 25

Scheduled Re-acquisitions: 17

Successful: 17

2.2 FHST Updates:

Scheduled: 37

Successful: 37

2.3 Operations Notes:

The SSR-1 EDAC error counter was cleared five times per ROP SR-1A.

There was a STIS EMC re-try at 025/110808Z. Using ROP NS-12, the
STIS flight software error counter was cleared at 025/1117Z.

An engineering status buffer limit (SESBSLD=5) was updated at
025/1934Z, using ROP DF-18A.

Real-time operations transferred to the GSFC Building 23 backup
facility at 026/1015Z in preparation for the ‘HST Backup Control Center
Test’. CCS string “C” was configured as the prime string at
026/1240Z. Operations returned to CCS string “A” at 026/1814Z. Operations
personnel returned to the STScI SIMOR at 026/2230Z.

As directed by ROP IC-1, SSA transmitter #2 was turned on and off
for the interval 026/2213Z to 026/2242Z.

The STIS MCE-2 reset at 027/004326Z while the low voltage was on
and while outside any SAA interval. The STIS flight software error counter
was cleared at 027/0053Z per ROP NS-12. MAMA-2 was recovered via normal
SMS command at 027/020204Z.

The engineering status buffer was dumped and cleared at 027/0328Z
per ROP DF-18A.


Continuation of normal science observations and calibrations.

SpaceRef staff editor.