HUBBLE SPACE TELESCOPE

   DAILY REPORT #2590

PERIOD COVERED:  0000Z (UTC) 03/28/00 - 0000Z (UTC) 03/29/00

Daily Status Report as of 089/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed 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.

    1.2 Completed Five Sets of WF/PC-2 8090 (POMS Test Proposal: WF-II 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used in the parallel mode to make some low galactic 
latitude archive observations.  The program will be used to take parallel 
images of random areas of the sky.  The observations were executed as 
scheduled, and no anomalies were noted.

    1.3 Completed Two Sets of STIS/MA1 8426 (Cycle 8 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) was used to make a 
routine Cycle-8 MAMA dark noise calibration measurement.  This proposal 
will provide the primary means of checking on the health of the MAMA 
detectors.  This is done through frequent monitoring of the background 
count rate.  The observations were completed as planned, and no problems 
were reported.

        1.4   Completed Three 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.

    1.5 Completed FGS 8319 (Masses and Distances of Pre-Main Sequence Binaries)

        The Fine Guidance Sensors were used to make astrometric 
observations of the pre-main sequence binary star system 
DF-TAU.  Observations were also made of several reference stars.  Our goal 
is to measure the masses of low mass young stars.  This will enable a 
calibration of theoretical calculations of stellar evolution to the main 
sequence.  The observations were completed as planned and no problems were 
reported.

    1.6 Completed WF/PC-2 8247 (Hidden New-Born Massive Stars in Compact H 
II ``Blobs'' of the Large Magellanic Cloud)

        The WF/PC-2 was used to perform high spatial resolution imaging to 
resolve very tight clusters of massive stars at birth in the Large 
Magellanic Cloud.  These are the youngest massive stars accessible to 
direct observations at ultraviolet and optical wavelengths.  The 
observations completed nominally.

    1.7 Completed Two Sets of STIS/CCD 7912 (STIS Parallel Archive Proposal 
- Nearby Galaxies - Imaging and Spectroscopy)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
parallel observations of nearby galaxies.  This survey will be useful to 
study the star formation histories, chemical evolution, and distances to 
these galaxies.  These data will be placed immediately into the Hubble Data 
Archive.  The observations were completed as scheduled, and no problems 
were reported.

    1.8 Completed 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.

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

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

    1.11 Completed STIS/CCD 8796 (POMS Test Proposal: STIS Non-Scripted 
Parallel Proposal Continuation IV)

        The Space Telescope Imaging Spectrograph (CCD) was used in the 
parallel mode to make some low galactic latitude archive observations.  The 
observations were executed as scheduled, and no anomalies were noted.

    1.12 Completed WF/PC-2 8248 (Observations of Potential JVAS/CLASS 
Gravitational Lenses)

        The WF/PC-2 was used to perform JVAS/CLASS gravitational lens 
surveys.  These surveys have been the most successful so far at finding new 
arcsecond-scale gravitational lenses.  A total of 17 confirmed systems have 
been discovered.  One surprising result is the number of doubly-imaged 
lensed systems compared to "quad'' configurations.  The doubles are 
under-represented in the current JVAS/CLASS lens sample by a factor 5 based 
on conventional models of the lensing galaxies.  The observations completed 
with no reported anomalies.

    1.13 Completed STIS/CCD/MA1 8435 (LSF Measure of the MAMA Echelle Modes)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
measure the LSF of the Echelle modes with an external target using a narrow 
slit.  As described in 2.1 and HSTAR 7552, the acquisition for this 
proposal defaulted to fine lock backup on one FGS only, possibly affecting 
the observations.  Otherwise, the proposal completed nominally.

    1.14 Completed STIS/CCD/MA1 8241 (A Snapshot Survey of Interstellar 
Absorption Lines)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
make high resolution Echelle spectrographic observations of the standard 
ultraviolet star HD75309 as part of a snapshot survey of interstellar 
absorption lines.  A wavelength calibration image was also taken.  The 
observations were executed as scheduled, and no anomalies were noted.

    1.15 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.

    1.16 Completed Three Sets of WF/PC-2 8457 (UV Earth Flats)

        The WF/PC-2 was used to obtain a series of Ultraviolet Earth 
flats.  The observations were completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

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

        The acquisition at 088/151522Z defaulted to fine lock backup on 
FGS-3 only when the scan step limit was exceeded on FGS-1.  HSTAR 7552 was 
written.  The proposal described in 1.13 may have been affected.
  Scheduled Re-acquisitions: 14
Successful: 14

    2.2 FHST Updates:
Scheduled: 11
Successful: 11

    2.3 Operations Notes:

        A TTR was written for a period of degraded data from 089/043656Z 
until 089/043849Z due to a T1 line problem.  Both engineering and science 
data was affected.  A line outage recorder playback has been requested.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW