HUBBLE SPACE TELESCOPE

   DAILY REPORT #2939

PERIOD COVERED:  0000Z (UTC) 08/17/01 - 0000Z (UTC) 08/20/01

Daily Status Report as of 232/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Six Sets of STIS/CCD 8808 (POMS Test Proposal: STIS 
Non-Scripted Parallel Proposal Continuation III)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
non-scripted, parallel observations as part of a POMS test proposal.  The 
observations completed with no anomalous activity.

    1.2 Completed Three Sets of WF/PC-2 9042 (An Archive To Detect The 
Progenitors Of Massive, Core-Collapse Supernovae)

         The WF/PC-s was used to search for supernovae which have massive 
star progenitors.  The already extensive HST archive and high-resolution 
ground-based images of galaxies within ~20 Mpc enables us to resolve and 
quantify their individual bright stellar content.  As massive, evolved 
stars are the most luminous single objects in a galaxy, the progenitors of 
core-collapse supernovae should be directly detectable on pre-explosion 
images.  One Type II progenitor has been observed this year, and the 
investigators have proposed a short, companion WFPC2 proposal to confirm 
this candidate and identify a second.  The observations completed nominally.

    1.3 Completed Three Sets of 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.

    1.4 Completed Five Sets of 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.

    1.5 Completed Six 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.  As described in HSTAR 8308, the acquisition for the 
final two iterations of this proposal defaulted to fine lock backup on one 
FGS, only, possibly affecting observations.  Otherwise, the proposal 
completed nominally.

    1.6 Completed Seven 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.  As described in HSTAR 8308, the acquisition for the final three 
iterations of this proposal defaulted to fine lock backup on one FGS, only, 
possibly affecting observations.  Otherwise, the proposal completed with no 
reported problems.

    1.7 Completed FGS/1 9168 (The Distances to AM CVn Stars)

        Fine Guidance Sensor (FGS) #1 was used to determine the parallaxes 
and proper motions of the five brightest of the seven known AM CVn 
systems.  AM CVn systems are binaries where mass is transferred from a 
completely hydrogen-deficient, degenerate mass donor to a white dwarf 
primary through a helium accretion disk.  A better understanding of these 
systems is crucial for a number of reasons: (1) to study the late stages of 
binary evolution, (2) to study the effect of chemical composition on the 
physics of accretion discs, (3) to estimate their contribution to the 
Supernovae Ia rate, and (4) to estimate their contribution to the 
gravitational radiation background.  All observations completed with no 
reported problems.

    1.8 Completed Five 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.

    1.9 Completed Three Sets of STIS/CCD 8907 (Spectroscopic Flats C10)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
CCD flats in the spectroscopic mode.  There were no reported problems.

    1.10 Completed STIS/CCD/MA1/MA2 9036 (An Ultraviolet Spectroscopic 
Survey of Star-Forming Galaxies in the Local Universe)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to perform a comprehensive STIS ultraviolet spectroscopic survey of 
star-forming galaxies in the local universe.  The sample covers a broad 
range of morphologies, chemical composition, and luminosity.  The 
observations will provide spectral coverage between 1200 and 3100 Angstrom, 
at a resolution of 100 to 200 kms and S/N of about 30.  The data set will 
allow the proposers to document and quantify the effects of massive stars 
on the interstellar medium and to infer implications for the evolution of 
the host galaxies.  The proposal completed with no anomalous activity.

    1.11 Completed Four Sets of WF/PC-2 8867 (Gamma-Ray Bursts: Discovering 
The Progenitors And Understanding The Explosion - Visits A0-R0)

        The WF/PC-2 was used to observe a gamma-ray bursters, GRB970828 and 
GRB000131.  Gamma-ray burst astronomy, one of the most active and exciting 
frontiers in astrophysics, is now entering a critical stage -- with 
dramatic leaps in understanding of these events, as well as new 
discoveries.  Improvements in triggering and positioning accuracy provided 
by the SAX and HETE-2 gamma-ray satellites will allow entirely new classes 
of events to be studied.  Given the recent progress in this field, the 
proposers are now in a position to design precision, broadband measurements 
that can provide quantitative information on the as-yet unknown energy 
sources, the explosion geometry, and the surrounding medium.  In 
particular, the growing evidence of an intimate connection between SNe and 
GRBs can be definitively tested.  The proposal completed with no reported 
problems.

    1.12 Completed Three Sets of STIS/CCD 9077 (Survey of the LMC Planetary 
Nebulae)

        The Space telescope Imaging Spectrograph (CCD) was used to perform 
a snapshot survey of all known LMC planetary nebulae {PNe} in order to 
study the co-evolution of the nebulae and their central stars, and to probe 
the chemical enrichment history of the LMC.  As described in HSTAR 8308, 
the acquisition for the final iteration of this proposal defaulted to fine 
lock backup on one FGS, only, possibly affecting observations.  Otherwise, 
there were no other reported problems.

    1.13 Completed WF/PC-2 9258 (Observatory Focus Monitor)

        The WF/PC-2 was used to more accurately define the HST focus.  The 
HST focus drifts slowly and shows evidence of undergoing slips of a few 
microns at random times.  The rate of the WF/PC-2 monitoring program is 
insufficient to track and/or understand OTA behavior in order to request 
timely and appropriate Secondary Mirror corrections.  There were no 
reported problems.

    1.14 Completed Five Sets of WF/PC-2 9060 (Photometry of a Statistically 
Significant Sample of Kuiper Belt Objects)

        The WF/PC-2 was used to propel the physical study of KBOs forward 
by performing accurate photometry at V, R, and I on a sample of up to 150 
KBOs.  The sample is made up of objects that will be observed at thermal 
infrared wavelengths by SIRTF and will be used with those data to derive 
the first accurate diameters and albedos for a large sample of KBOs.  The 
observations completed nominally.

    1.15 Completed STIS/MA2 8863 (NUV-MAMA Cycle 9 Flats)

        The Space Telescope Imaging Spectrograph (MA2) was used to obtain 
NUV-MAMA observations of the internal Deuterium lamp to construct an NUV 
flat applicable to all NUV modes.  There were no reported problems.

    1.16 Completed Two Sets of WF/PC-2/STIS/CCD 8577 (Ozone, Condensates, 
and Dust in the Martian Atmosphere)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were 
used to study the spatial and seasonal variations in ozone, condensates, 
and dust in the Martian atmosphere.  The data obtained promise to be 
critical in addressing recent breakthroughs in understanding the basic 
radiative, transport, and microphysical processes that provide for both 
long-term and short-term balance within the global Mars climate 
system.  There were no reported problems.

    1.17 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.

    1.18 Completed WF/PC-2 9043 (Cepheid Distances to Early-type Galaxies)

        The WF/PC-2 was used to continue observations in the HST Key 
Project on the Extragalactic Distance Scale and the HST project on the 
"Calibration of Nearby Type Ia Supernovae'' that have greatly improved our 
knowledge of the Hubble Constant by providing a solid zero point for the 
Tully- Fisher {TF} relation and Type Ia Supernovae {SNIa}.  However, severe 
inconsistencies remain for distance estimators to early-type galaxies such 
as surface brightness fluctuations {SBF}, the planetary nebula luminosity 
function {PNLF}, the fundamental plane {FP}, and the globular cluster 
luminosity function {GCLF}.  As a result, the distance to the Virgo cluster 
core remains uncertain by as much as 20 determination is directly affected 
by a lingering 0.1 mag {5 uncertainty in the photometric calibration of the 
WFPC2.  Resolving these issues is essential not only to firm up the 
extragalactic distance scale, but also to understand the mass and velocity 
structure of the local universe. SBF in particular is emerging as the 
method of choice for mapping local velocity fields to 10, 000 kms because 
it offers an order of magnitude less Malmquist bias than TF, and SNIa are 
too rare to study large scale flows effectively.  This project will tighten 
the photometric calibration of the WFPC2, and provide a solid Cepheid 
calibration for SBF and PNLF.  The observations completed nominally.

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

        The Space Telescope Imaging Spectrograph (CCD) 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.

    1.20 Completed Two Sets of 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.

    1.21 Completed WF/PC-2 9124 (Mid-UV SNAPSHOT Survey of Nearby 
Irregulars: Galaxy Structure and Evolution Benchmark)

        The WF/PC-2 was used to investigate the relation between star 
formation and the global physical characteristics of galaxies to interpret 
the morphologies of distant galaxies in terms of their evolutionary 
status.  Distant galaxies are primarily observed in their rest frame 
mid-ultraviolet.  They resemble nearby late-type galaxies, but are they 
really physically similar classes of objects?  It is proposed to address 
this question through a SNAPSHOT survey in the 2 mid-UV filter F300W of 98 
nearby late-type, irregular and peculiar galaxies.  No problems were reported.

    1.22 Completed WF/PC-2 9133 (Imaging of Gravitational Lenses)

        The WF/PC-2 was used to observe gravitational lenses that offer 
unique opportunities to study cosmology, galactic structure, galaxy 
evolution, quasar hosts and extinction.  They are also the only sample of 
galaxies selected on the basis of their mass rather than their luminosity 
or surface brightness.  While gravitational lenses can be discovered with 
ground-based optical and radio observatories, converting them from 
curiosities into scientific tools requires HST.  There were no reported 
anomalies.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 22
Successful: 22

        Per HSTAR 8308, the acquisition at 230/5907Z defaulted to fine lock 
backup on FGS-1 only when the scan step limit was exceeded on FGS-3.  The 
proposals detailed in 1.5, 1.6 and 1.12 may have been affected.
  Scheduled Re-acquisitions: 19
Successful: 19

    2.2 FHST Updates:
Scheduled: 43
Successful: 43

    2.3 Operations Notes:

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

        A TTR was written for required re-transmits during a NSSC-1 loads 
at 229/1927Z and at 230/0403Z.  On each occasion, ROP NS-5 was utilized to 
reset the SI C&DH error counter.

        There was a STIS EMC re-try at 229/152637Z.  Using ROP NS-12, the 
STIS flight software error counter was reset at 229/1528Z.

        A TTR was written when data was lost for the interval 230/045555Z 
to 230/045658Z due to a MA Cal fail over.

        HSTAR 8307 was written when the gyro #3 current flagged 
out-of-limits low at 230/094035Z with a reading of 196.00 amps.

        Per ROP NS-3, the NSSC-1 status buffer was dumped and reset at 
230/2208Z.

        SSA transmitter #2 was turned on at 231/0909Z and turned off at 
231/0926Z as directed by ROP IC-2.

        The engineering status buffer limits were adjusted at 232/0451, 
using ROP DF-18A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW