HUBBLE SPACE TELESCOPE

   DAILY REPORT #2844

PERIOD COVERED:  0000Z (UTC) 04/04/01 - 0000Z (UTC) 04/05/01

Daily Status Report as of 095/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD/MA2 8681 (Snapshot Survey of Variability of 
Narrow and Broad Associated Absorption Lines in Quasars)

        The Space telescope Imaging Spectrograph (CCD and MA2) was used to 
investigate the variability in the strength of absorption lines in quasar 
spectra which is definitive proof that we are observing material that is 
physically associated with the quasars.  This proposal will conduct a STIS 
snapshot survey to provide second epoch observations of 37 quasars with 
narrow associated or broad absorption lines {NALs and BALs}, previously 
observed with the FOS.  At high redshift several intrinsic NALs and about 
two thirds of BALs are known to vary, often in accord with continuum 
variability.  The amplitudes increase and the timescales decrease with 
decreasing quasar luminosity.  The proposal completed nominally.

    1.2 Completed Two 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.

    1.3 Completed Three Sets of 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.

    1.4 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.

    1.5 Completed Four 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 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.

    1.7 Completed STIS/CCD/MA1/MA2 8857 (MAMA Sensitivity and Focus Monitor C9)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to monitor the sensitivity of each MAMA grating mode to detect any 
change due to contamination or other causes.  There were no problems.

    1.8 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.

    1.9 Completed FGS/2R 8831 (Long Term Stability in Transfer Mode)

        Fine Guidance Sensor #2R was used to continue a SMOV3a proposal and 
a cycle 8 calibration proposal to monitor the FGS2R S-curves during its 
first 1.5 years in orbit.  The standard star Upgren69, known to be a point 
source at FGS resolution, will be observed in Transfer Mode at the center 
of the FGS2R FOV using both the F583W filter and the 2/3 PUPIL stop.  The 
observations completed with no reported problems.

    1.10 Completed Three Sets of STIS/CCD 8851 (Sparse Field CTE test 
{Cycle 9})

        The Space Telescope Imaging Spectrograph (CCD) was used to perform 
CTE measurements that are made using the "sparse field test", along both 
the serial and parallel axes.  The proposal completed with no reported 
anomalies.

    1.11 Completed Two Sets of STIS/CCD/MA1 8582 (UV Detectability of 
Bright Quasars in the Sloan Fields)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
examine the He II Ly alpha absorption at 304{1+z} Angstrom which is a far 
more sensitive tracer of the intergalactic medium {IGM} than its H I 
counterpart.  The recent detections of such absorption in four quasars, 
albeit with limited data quality and a small sample size, demonstrate the 
great potential of such a probe.  There were no reported problems.

    1.12 Completed Two Sets of STIS/MA1 8843 (Cycle 9 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) was used to perform 
the routine monitoring of the MAMA detector dark noise.  The proposal 
completed nominally.

    1.13 Completed WF/PC-2 8682 (A Snapshot Study of 0bservational Cosmology)

        The WF/PC-2 was used to examine the observational constraints on 
the cosmic star formation history that is currently among the most active 
fields in observational cosmology.  The most widely used tracer of the 
co-moving volume-averaged star formation rate {SFR} is the UV luminosity 
density, which early results found to peak at z~1- 2.  The apparent 
identification of the primary epoch of metal production and star formation 
in the Universe led to intense theoretical and observational 
interest.  Nevertheless, and remarkably for such a fundamental observation, 
little is known about the history of star formation in the Universe beyond 
its global average.  There were no reported anomalies.

    1.14 Completed WF/PC-2 8720 (Masses and Multiplicity of Nearby Free- 
floating Methane and L Dwarfs)

        The WF/PC-2 was used to observe 50 very-low-mass objects in the 
solar neighborhood with spectral types of L0 and later {including several 
dwarfs with Methane absorption bands in their atmospheres}.  These objects 
will be observed in two filter bands with the aim to identify close 
companions, measure their colors, and to obtain first epoch data of the 
newly discovered binaries.  The observations completed nominally.

    1.15 Completed STIS/CCD 8259 (The Origin of Blue Wings on NLR Line 
Profiles)

        The Space Telescope Imaging Spectrograph (CCD) was used to attempt 
understanding the kinematics of the Narrow Line Region {NLR} in Seyfert 
galaxies.  The observational signature being looked for is the famous `blue 
wing' found on the OIIILambda5007 lines of almost all Seyfert 
galaxies.  The proposal completed with no reported problems.

    1.16 Completed WF/PC-2/STIS/CCD 8679 (Constraining the Age of the 
Oldest Stars from the White Dwarf Cooling Sequence in M4)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were 
used to search for the oldest and hence coolest white dwarfs {WDs} in M4, 
the nearest Galactic globular cluster to the Sun.  New models for cooling 
hydrogen white dwarfs predict that their colors should become bluer, rather 
than redder, with increasing age. The goal is to test these models and at 
the same time constrain the age of M4.  The proposal completed with no 
problems.

    1.17 Completed STIS/CCD 8591 (The Smallest Nuclear Black Holes)

        The Space Telescope Imaging Spectrograph (CCD) was used to observe 
small nuclear black holes which are the last major unexplored part of BH 
parameter space, searching for the smallest BHs that HST can possibly 
find.  The proposal completed with no reported anomalies.

    1.18 Completed 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.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  7
Successful: 7

  Scheduled Re-acquisitions:  8
Successful:  8

    2.2 FHST Updates:
Scheduled: 19
Successful: 19

    2.3 Operations Notes:

        Using ROP SR-1A, the SSR EDAC error counter was cleared twice.

        No problems were encountered while checking out the CCS Release 3.4 
on the "B" string.

        A TTR was written for a required re-transmission at 095/0253Z 
during a NSSC-1 load.  Per ROP NS-5, the engineering report was 
subsequently reset at 095/0258Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW