HUBBLE SPACE TELESCOPE

       DAILY REPORT #2942

PERIOD COVERED:  0000Z (UTC) 08/22/01 - 0000Z (UTC) 08/23/01

Daily Status Report as of 235/0000Z

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 Two Sets of WF/PC-2 8828 (Cycle 9 Supplemental Darks pt3/3)

        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 with no reported problems.

    1.3 Completed STIS/CCD/MA1/MA2 9176 (LMC Eclipsing Binaries with 
Cepheid Components: The Key to the Extragalactic Distance Scale)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to determine the distance to the LMC and to observe the Cepheid P-L 
that law form the backbone of the Cosmic Distance Scale and the 
determination of H_degrees.  Unfortunately, in spite of concerted efforts 
of many investigators, the zero point of the Cepheid P-L law and the LMC 
distance remain controversial and uncertain to ~10-15, using eclipsing 
binaries {EBs} as "standard candles'' to include two recently discovered 
LMC eclipsing binaries {EBs} with Cepheid components.  These observations 
of these extraordinary systems hold the key to determining simultaneously 
the Cepheid P-L zero point and the LMC distance, and to provide a direct 
test of the Baade-Wesselink parallax method.  There were no reported problems.

    1.4 Completed Two 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.

    1.5 Completed WF/PC-2 8059 (POMS Test Proposal: Targeted Parallel 
Archive Proposal)

        The WF/PC-2 was used to observe the parallel opportunities 
available in the neighborhood of bright galaxies are treated in a slightly 
different way from the normal pure parallels.  Local Group galaxies offer 
the opportunity for a closer look at young stellar 
populations.  Narrow-band images in F656N can be used both to identify 
young stars via their emission lines, and to map the gas distribution in 
star-forming regions.  The observations completed nominally.

    1.6 Completed STIS/CCD/MA1/MA2 9287 (Ultraviolet Observations of the 
Death Star in Outburst)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to observe WZ Sge, a "death star".  A few days ago, amateur 
astronomers have established that this cataclysmic variable star has gone 
into outburst, 23 years after the last outburst event and about 10 years 
earlier than expected.  The system rose from V=15 to V=8 in the course of a 
day and is expected to remain in outburst for about 1-2 months.  WZ Sge is 
arguably the most extreme and interesting cataclysmic variable {CV} in the 
sky.  Whereas other dwarf-nova-type CVs undergo 3-5 magnitude eruptions 
every few weeks or months, WZ Sge's outbursts have an amplitude of 7-8 
magnitudes and recur on a time-scale of roughly 33 years.  In addition, WZ 
Sge's 82 minute orbital period is one of the shortest of any CV, its mass 
ratio of M2/M1 is one of the lowest and its time-averaged absolute 
magnitude one of the faintest.  All of these facts imply that WZ Sge is a 
"death star" i.e. a highly evolved cataclysmic binary in which gigayears of 
mass transfer have converted an initially main sequence secondary star to a 
0.02 solar mass brown dwarf.  The observation completed with no reported 
problems.

    1.7 Completed 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.

    1.8 Completed STIS/CCD/MA1/MA2 8849 (Faint Standard Extension)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to observe fainter standard stars that are needed for the flux 
calibration of COS, while re-observations are required to check for 
variability and to improve S/N.  The observations completed nominally.

    1.9 Completed 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.  As documented in HSTAR 8314 and 2.1, the acquisition for this 
proposal defaulted to fine lock backup on one FGS only, possibly affecting 
six observations.  Otherwise, the proposal completed uneventfully.

    1.10 Completed WF/PC-2 9138 (Host Galaxies of Gravitationally Lensed 
Quasars)

        The WF/PC-2 was used to perform imaging studies of quasar host 
galaxies at high redshift that are biased toward detecting luminous 
hosts.  Gravitational lensing combined with optical and near-IR imaging 
enhances their detectivity and has nearly doubled the number of known hosts 
at z>1.  Lens studies have successfully imaged hosts with lower 
luminosities at farther distances beneath a larger fraction of quasars than 
imaging of non- lensed quasars.  We propose deep WFPC2 follow-up imaging of 
five lensed systems in the F555W and F814W filters, which offer unique 
opportunities for detailed studies of faint, high-redshift, quasar 
hosts.  As documented in HSTAR 8314 and 2.1, the acquisition for this 
proposal defaulted to fine lock backup on one FGS only, possibly affecting 
eight observations.  Otherwise, the proposal completed as planned.

    1.11 Completed WF/PC-2 9135 (A New High-Z Galaxy Cluster with 
Extraordinary Lensed Arcs From Multiple Sources)

        The WF/PC-2 was used to observe strong lensing by a relatively high 
redshift {z~0.7} cluster in the Red-Sequence Cluster.  This lens system has 
more bright arcs, with better cluster azimuthal coverage than examples of 
lower z lenses previously imaged.  At least 4 separate arcs are detected in 
our initial survey data, at 3-4 different cluster-centric radii and hence 
likely corresponding to at least 3 different background sources at 3 
different redshifts.  Moreover, these arcs are relatively bright and hence 
redshifts should be readily obtainable using 8m class telescopes.  All 
observations completed normally.

    1.12 Completed STIS/CCD 9285 (POMS Test Proposal: STIS Non-scripted 
Parallel Proposal Continuation III)

        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.

    1.13 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 STIS/CCD 9187 (A Lyman Limit Snapshot Survey: The Search 
for Candidate D/H Absorbers)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
D/H in gas clouds seen against background QSOs.  This provides a unique and 
fundamental cosmological probe of the baryonic density parameter.  To date, 
most of the QSO absorption line D/H constraints have been derived at high 
redshift.  In this proposal the proposers investigate a lower redshift 
range, because there are two potentially crucial advantages to be gained by 
carrying out D/H measurements at intermediate redshift.  First, the 
background of HI forest lines is lower and contamination of the DI feature 
is significantly reduced.  Second, a far larger sample of very bright QSOs 
exists.  There were no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  6
Successful:  6

        As described in HSTAR 8314, the acquisition at 234/155929Z 
defaulted to fine lock backup on FGS-3 only when the scan step limit was 
exceeded on FGS-2.  The proposals detailed in 1.9 and 1.10 may have been 
affected.
  Scheduled Re-acquisitions:  9
Successful:  9

    2.2 FHST Updates:
Scheduled: 12
Successful: 12

    2.3 Operations Notes:

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

        Flight software 2.0B EEPROM and 2.0C RAM installation occurred 
successfully at 234/1330Z.  This installation, together with related 
installations performed yesterday and another installation tomorrow, 
changes the post-SM3B Diode Bus Controller commanding and fixes the 
Magnetic Torquer echo check timing.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Installation of 2.0C EEPROM flight software today.

        Continuation of normal science observations and calibrations.

/CAW