HUBBLE SPACE TELESCOPE

   DAILY REPORT #2938

PERIOD COVERED:  0000Z (UTC) 08/16/01 - 0000Z (UTC) 08/17/01

Daily Status Report as of 229/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Eight 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 Two 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 burster, 
GR970828.  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.

    1.3 Completed Four 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.

    1.4 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.

    1.5 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.

    1.6 Completed Seven 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.

    1.7 Completed 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 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.

    1.9 Completed Three 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.

    1.10 Completed Two Sets of 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.

    1.11 Completed 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.

    1.12 Completed GFS/1 8897 (Long Term Monitoring of FGS1R in Position Mode)

        Fine Guidance Sensor #1R was used to monitor its long term 
evolution, presumably due to disorption of water from the instrument's 
graphite epoxy composits.  This manifests principally as a change in the 
plate scale and secondarily as a change in the distortions.  These effects 
are well modeled by adjustments to the rhoA and kA parameters which are 
used to transform the star selector servo angles into FGS {x, y} detector 
space coordinates.  By observing the relative positions of stars in a 
standard cluster at a fixed telescope pointing and orientation, the 
evolution of rhoA and kA can be monitored and calibrated to preserve the 
astrometric integrity of the FGS.  There were no reported problems.

    1.13 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.

    1.14 Completed STIC/CCD/MA2 9051 (Identifying Damped Lyman-alpha 
Galaxies at z~1)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
look for samped Lyman-alpha absorption systems that contain the bulk of the 
neutral gas in the Universe in the redshift range z = 0.5 - 5 ,yet the 
nature of the galaxies responsible for the absorption is not well 
understood.  Only recently have observers found more than a handful of 
damped absorbers at redshifts z < 1.5.  Using the FIRST Bright Quasar 
Survey {FBQS}, with over a 1000 quasars, the proposers have undertaken a 
survey to build a complete picture of he nature of the galaxies responsible 
for damped Lyman-alpha absorption systems at z~1 and to double the sample 
size at this redshift.  No problems were encountered.

    1.15 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.

    1.16 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.

    1.17 Completed WF/PC-2 9249 (POMS Test Proposal: WFII Backup Parallel 
Archive Proposal II)

        The WF/PC-2 was used to execute a POMS test proposal designed to 
simulate scientific plans.  The proposal completed with no reported problems.

    1.18 Completed STIS/CCD 9110 (A Search for Kuiper Belt Object Satellites)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
investigate whether the large number of collisions thought to have taken 
place in the primordial Kuiper belt suggest that many Kuiper belt objects 
{KBOs} could have suffered binary-forming collisions similar to that which 
formed the Pluto -- Charon binary.  Detection of such KBO satellites would 
allow measurement of  KBO masses, would help to understand the past 
collisional environment of the Kuiper belt, and would give a context to the 
otherwise unique-seeming formation of the Pluto -- Charon binary.  The 
proposal completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 10
Successful: 10

  Scheduled Re-acquisitions:  5
Successful:  5

    2.2 FHST Updates:
Scheduled: 28
Successful: 28

    2.3 Operations Notes:

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

        A TTR was generated when HST Internal Ground Configuration Data was 
lost from 228/211216Z until 228/211528Z.  This data is unrecoverable.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW