HUBBLE SPACE TELESCOPE

  DAILY REPORT #2849

PERIOD COVERED:  0000Z (UTC) 04/11/01 - 0000Z (UTC) 04/12/01

Daily Status Report as of 102/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD 8864 (CCD Dark Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks for the CCD.  The proposal completed nominally.

    1.2 Completed Three Sets of WF/PC-2 8816 (Cycle 9 UV Earthflats)

        The WF/PC-2 was used to obtain sequences of Earth streak flats to 
improve the quality of pipeline flat fields for the WFPC2 UV filter set and 
in order to monitor flat field stability.  There were no reported problems.

    1.3 Completed Three Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)

        The WF/PC-2 was used to obtain three dark frames every day to 
provide data for monitoring and characterizing the evolution of hot 
pixels.  The proposal completed nominally.

    1.4 Completed STIS/CCD/MA2 8569 (A New Survey for Low-Redshift Damped 
Lyman-Alpha Lines in QSO MgII Systems)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
support studies which have shown that most of the observable neutral gas 
mass in the Universe resides in QSO damped LyAlpha {DLA} systems.  However, 
at low redshift, DLA can only be found by searching in the UV with HST.  By 
boot-strapping from the MgII statistics, we will be able to further improve 
the determination of the low- redshift statistical properties of DLA {their 
incidence and cosmological mass density} and open up new opportunities for 
studies at low redshift.  The observations completed nominally.

    1.5 Completed Eight Sets of WF/PC-2 9244 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
Archival Pure Parallel program.  The program will be used to take parallel 
images of random areas of the sky, following the recommendations of the 
Parallels Working Group.  The observations completed with no anomalous 
activity.

    1.6 Completed STIS/MA1 8572 (Identifying Normal Galaxies at 1.3 < z < 2.5)

        The Space Telescope Imaging Spectrograph (MA1) was used to perform 
studies of faint, distant galaxies.  It is now possible to observe hundreds 
of galaxies out to z=1 and in the range 3 < z < 4.5, yet the redshift range 
1 < z <3 remains largely unexplored.  No problems were noted.

    1.7 Completed STIS/CCD 8864 (CCD Dark Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks for the CCD.  The proposal completed nominally.

    1.8 Completed Two Sets of STIS/CCD/MA2 8711 (C/O Abundance Ratios 
Across WCL Planetary Nebulae With Strong PAH And Crystalline Silicate Emission)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
measure the required high angular resolution across compact nebulae for the 
crucial abundance-diagnostic lines of C ii 2326 Angstrom and O ii 2470 
Angstrom.   ISO has discovered cool O-rich crystalline silicate and water- 
ice emission in the far-IR spectra of several planetary nebulae {PNe} which 
show very strong hot PAH {polycyclic aromatic hydrocarbon, carbon-rich} 
emission bands in their near- and mid-IR spectra.  All of these PNe are 
young and compact and of low-ionization, and have cool H-deficient Wolf- 
Rayet central stars.  The correlation with carbon-rich WCL Wolf-Rayet 
central stars suggests that the phenomenon is associated with a recent 
transition from an O-rich to a C-rich phase by the evolving objects, 
following the exposure of 3rd dredge-up enriched material.  For these 
nebulae, the gas-phase C/O ratios {two of the nebulae have the largest C/O 
ratios known} are strongly correlated with the PAH feature strength.  The 
unexpected discovery of cool oxygen-rich particles around them suggests 
that strong C/O abundance gradients may be present in the nebulae.  The 
observations completed nominally.

    1.9 Completed Two Sets of WF/PC-2 8683 (Imaging Of Brightest Cluster 
Galaxies: The High End Of The Black Hole Mass Distribution)

        The WF/PC-2 was used to make kinematic black hole detections in 
galaxies to decide whether they indicate that the mass correlates with both 
optical luminosity and radio power.  The observation completed with no 
reported problems.

    1.10 Completed Nine Sets of STIS/CCD 9248 (Probing the Large Scale 
Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the distortion of light bundles from distant galaxies that probe the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  Its tidal gravitational field distorts the observable image 
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}.  The 
observations completed nominally.

    1.11 Completed  WF/PC-2 8677 (Extragalactic Novae: the Maximum 
Magnitude - Rate of Decline Relation in NGC 4472)

        The WF/PC-2 was used to accomplish two goals: {1} to provide the 
first homogeneous observational constraints on theoretical models for novae 
outbursts; and {2} to assess the reliability of novae as standard candles 
by using WFPC2 to collect well sampled light curves for 20-50 novae in the 
supergiant elliptical galaxy NGC 4472, the brightest galaxy within 30 
Mpc.  Both the length of the observing window and the temporal sampling of 
the observations are specifically designed to ensure that the novae peak 
magnitudes and decline rates are measured accurately.  These data will be 
used to construct the first `Maximum Magnitude versus Rate of Decline' 
{MMRD} relation for a galaxy beyond the Local Group.  This relation is not 
only a potentially powerful standard candle, but its shape and dispersion 
are directly linked to physical parameters which govern the physics of 
novae outbursts such as the white dwarf mass, temperature and mass 
accretion rate.  The proposal completed with no reported problems.

    1.12 Completed Three Sets of FGS/1R 8727 (Ultra-High Resolution Studies 
Of Agns III: Nuclear Extent And The SIM Astrometric Grid)

        Fine Guidance Sensor #1R was used to perform a follow-up to a pilot 
project (which used the original Fine Guidance Sensor astrometer {FGS3}) to 
study optical extent of several AGN.  Using the significantly enhanced 
performance of the new FGS1R, two high S-N AGN from our earlier sample, 
probing the broad line region at 10mas resolution, will be 
re-observed.  The observations completed with no reported problems.

    1.13 Completed STIS/CCD 8865 (Bias Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used 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.  The proposal completed with no anomalous activity.

    1.14 Completed WF/PC-2 8719 (A Continuation Of A Snapshot Survey Of X- 
Ray Selected Central Cluster Galaxies0

        The WF/PC-2 was used to perform snapshot images of a representative 
subset of the central cluster galaxies from an X-ray selected cluster 
sample that would provide important constraints on the formation and 
evolution of dust in cluster cores that cannot be obtained from 
ground-based observations.  The observations completed as planned.

    1.15 Completed WF/PC-2 8773 (Expansion Parallax Distances to Planetary 
Nebulae)

        The WF/PC-2 was used to observe planetary nebulae {PNe} for which 
the lack of reliable distances is especially troubling.  Acquired by 
generalized statistical methods in all but a handful of cases, individual 
PNe distances are often uncertain by factors of two or more.  The 
observations completed nominally.

    1.16 Completed WF/PC-2 8602 (A Snapshot Survey of the Sites of Recent, 
Nearby Supernovae)

        The WF/PC-2 was used to conduct a snapshot survey in V and I of the 
sites of the nearby SNe, which have precisely known positions, to obtain 
high-resolution information on their local environment.  The proposal 
completed with no reported problems.

    1.17 Completed STIS/MA2 8843 (Cycle 9 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA2) was used to perform 
the routine monitoring of the MAMA detector dark noise.  The proposal 
completed nominally.

    1.18 Completed STIS/CCD/MA1 8606 (Determining the Nature of the 
Variable Absorption in AGN: Monitoring NGC 3783 with HST And Chandra)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
investigate Seyfert 1 galaxies, many of which show intrinsic UV absorption 
lines, characterized by high moderate widths, significant outflow 
velocities, and variability on time scales as small as days.  Seyferts with 
UV absorption also show variable X-ray ``warm absorbers'', characterized by 
O VII and O VIII absorption edges, which suggests a common 
origin.  Variability monitoring is the key to understanding the absorbers, 
by providing their radial locations, densities, and evolution in 
ionization, column density, velocity, and coverage of the inner active 
nucleus.  The proposal completed with no problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 14
Successful: 14

  Scheduled Re-acquisitions:  2
Successful:  2

    2.2 FHST Updates:
Scheduled: 30
Successful: 30

    2.3 Operations Notes:

        The SSR EDAC error counter was cleared four times, using ROP SR-1A.

        The engineering status buffer limits were adjusted four times as 
directed by ROP DF-18A.

        SSA transmitter 2 was turned on and off for the interval 101/1516Z 
- 101/1544Z per ROP IC-2.

        Using ROP NS-08, an SI delayed error nulling maneuver was generated 
and then used at 101/1847Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        GSFC Internal Simulation #7 (EVA-3) will be conducted in the 
SMOR/MOR area from 8:00 a.m. today until approximately 1:30 a.m. tomorrow.

        Continuation of normal science observations and calibrations.

/CAW