HUBBLE SPACE TELESCOPE

   DAILY REPORT #2621

PERIOD COVERED:  0000Z (UTC) 05/10/00 - 0000Z (UTC) 05/11/00

Daily Status Report as of 132/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD/MA1/MA2 8265 (Reverberation Mapping of a 
Narrow-Line Seyfert 1 Galaxy)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to monitor the UV spectral variability of the narrow-line Seyfert 1 
{NLS1} galaxy Akn 564 at 46 epochs in order to measure the size of the 
broad emission-line region via reverberation-mapping techniques.  This 
measurement, and the virial mass estimate that follows from it, will 
provide a key test of NLS1 models and help determine the physical mechanism 
that underlies the principal component of AGN spectra, the Boroson--Green 
primary eigenvector.  These observations will be undertaken in parallel 
with X-ray and ground-based optical observations that will allow us for the 
first time to explore the multiwavelength variability characteristics of 
this important subclass of active galactic nuclei.  The observations 
completed with no reported problems.

    1.2 Completed Four Sets of WF/PC-2 8805 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
WFPC2 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.  The proposal completed with no reported problems.

    1.3 Completed Two Sets of WF/PC-2 8460 (Cycle 8 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 observations completed with no reported problems.

    1.4 Completed Three Sets of STIS/CCD 8439 (Bias Monitor-Part 2 C8)

        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 reported problems.

    1.5 Completed STIS/CCD/MA1/MA2 8424 (MAMA Sensitivity and Focus Monitor C8)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to make observations of object AGK+81D266 in order to measure the 
sensitivity and to focus monitor C8.  This also is to monitor sensitivity 
of each MAMA grating mode to detect any change due to contamination or 
other causes, and to monitor the STIS focus in a spectroscopic mode.  A 
wavelength calibration was also taken.  The observations were completed as 
planned, and no anomalies were reported.

    1.6 Completed Two Sets of STIS/CCD 8437 (Dark Monitor-Part 2 C8)

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

    1.7 Completed WF/PC-2/STIS/CCD 8213 (Globular Clusters of Low Surface 
Brightness Galaxies)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were 
used to investigate globular cluster {GC} systems in giant low surface 
brightness {LSB} galaxies.  The primary goals of the project are to 
determine the number of GCs in two nearby LSB galaxies and to estimate 
their ages.  LSB spirals tend to be more isolated, more gas rich, and have 
had more quiescent star formation than their high surface brightness {HSB} 
cousins.  LSB galaxies have either been forming stars very slowly for a 
Hubble time or have formed within the last few Gyr. T hus, their star 
formation histories may be very different from those of HSB galaxies.   The 
proposal completed nominally.

    1.8 Completed WF/PC-2 8166 (Narrow-Band HAlpha Imaging of the Edge-on 
Galaxy NGC4631)

        The WF/PC-2 was used to make observations of nearby edge-on disk 
galaxies which are essential to determine the role that the disk/halo 
interaction has in galaxy evolution.  Located in a direction of 
exceptionally low Galactic extinction, NGC4631 is particularly suitable for 
a multi-wavelength investigation of extra-planar gas components.  The 
observations completed nominally.

    1.9 Completed STIS/CCD 8549 (POMS Test Proposal: Non-Scripted Parallel 
Proposal Continuation I)

        The Space Telescope Imaging Spectrograph (CCD) was used to make low 
galactic latitude, non-scripted parallel observations as part of a POMS 
test proposal.  The observations were completed as planned, and no 
anomalies were reported.

    1.10 Completed Three Sets of WF/PC-2 8445 (WF/PC-2 Cycle 8 Earth Flats)

        The WF/PC-2 was used to make Cycle 8 Earth flat calibration 
observations.  This is to obtain sequences of earth streak flats to 
construct high quality flat fields for the WF/PC-2 filter set.  The 
observations were executed as scheduled, and no anomalies were noted.

    1.11 Completed STIS/CCD/MA1 8284 (Deep STIS Observations of BALQSO PG 
0946+301)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
study AGN outflows to determine of the ionization equilibrium and 
abundances (IEA) in broad absorption line {BAL} QSOs.  In the last few 
years it has become clear that partial coverage of the continuum source and 
saturation are common in BALs, and these frustrate attempts to determine 
the IEA from available HST data because of limitations imposed by the S/N 
ratio and spectral coverage. We will re-observe the most suitable BAL IEA 
target: PG 0946+301.  The observation completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  5
Successful:  5

  Scheduled Re-acquisitions: 13
Successful: 13

    2.2 FHST Updates:
Scheduled:  6
Successful:  6

    2.3 Operations Notes:

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

        Per ROP IC-2, the SSA transmitter was turned on and off once.`

        A TTR was written when a Mode 1 switch failed, resulting in 
real-time data loss from 131/223157Z to 131/223450Z and from 131/223619Z to 
131/223827Z.  Operations Note #725 was executed at 131/2238Z for the MAR 
coherent acquisition failure.

        CCS string "C" (backup for release 3.2) was removed from 
operational usage due to NCC related problems.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW