HUBBLE SPACE TELESCOPE

   DAILY REPORT #2921

PERIOD COVERED:  0000Z (UTC) 07/24/01 - 0000Z (UTC) 07/25/01

Daily Status Report as of 206/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/MA1 8572 (Identifying Normal Galaxies at 1.3 < z < 2.5)

        The Space Telescope Imaging Spectrograph (MA1) was used to perform 
studies of faint, distant galaxies.  It is now possible to observe hundreds 
of galaxies out to z=1 and in the range 3 < z < 4.5, yet the redshift range 
1 < z <3 remains largely unexplored.  No problems were noted.

    1.2 Completed Seven 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.

    1.3 Completed WF/PC-2 8826 (Cycle 9 Supplemental Darks pt 1)

        The WF/PC-2 was used to perform a T dark calibration program that 
obtains three dark frames every day in order to provide data for monitoring 
and characterizing the evolution of hot pixels.  There were no reported 
anomalies.

    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 WF/PC-2 8597 (The Fueling of Active Nuclei: Why are 
Active Galaxies Active?)

        The WF/PC-2 was used to investigate the accretion onto massive 
black holes that are believed to be the energy source for AGN.  However, 
evidence for black holes in quiescent galaxies has also been reported.  Why 
are these galaxies inactive?  One possibility is that active galaxies are 
better at providing fuel to the nuclear region than quiescent 
galaxies.  Other possible fueling mechanisms such as ``bars-within-bars'' 
or nuclear spirals cannot be investigated from the ground because they are 
relatively small features in the ISM.  The observations were completed as 
planned.

    1.6 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.

    1.7 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 Twelve 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.

    1.10 Completed STIS/CCD 9121 (Evolution of the Host Galaxies in Low- 
Power AGN)

        The Space Telescope Imaging Spectrograph (CCD) was used to study 
the evolution of low-power AGN host galaxies to z~1.3, allowing the direct 
study of how the formation and life cycles of radio-loud AGN depend on 
intrinsic power.  There were no reported problems.

    1.11 Completed WF/PC-2 9252 (Cycle 10 Clocks On Check)

        The WF/PC-2 was used to perform closure calibration for clocks 'on' 
mode, which obtains dark frames in order to provide data to create a clocks 
'on' super dark calibration reference file, to monitor and characterize the 
evolution of hot pixels, and to obtain standard star observations for 
photometric calibration.  The proposal completed with no reported anomalous 
activity.

    1.12 Completed Five Sets of FGS/1 9169 (An Interferometric Harvest of 
Double Degenerates)

        Fine Guidance Sensor #1 was used to observe the white dwarf mass 
and age distributions that hold clues to the star formation history of our 
Galaxy and the age of the disk.  No problems were reported.

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

        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.

    1.14 Completed FGS/1 9034 (The Masses and Luminosities of Population II 
Stars)

        Fine Guidance Sensor #1 was used to observe the mass-luminosity 
relation {MLR} of Population II stars of which very little is currently 
known.  With the advent of the Hipparcos Catalogue, improved distances to 
many spectroscopic binaries known to be Pop II systems are now 
available.  After surveying the literature and making reasonable estimates 
of the secondary masses, we find 13 systems whose minimum separation should 
be larger than the resolution limit of FGS #1.  The observations completed 
nominally.

    1.15 Completed WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)

        The WF/PC-2 was used to perform a snapshot survey of local galaxies 
at UV wavelengths with the F300W filter.  The aim of the project is to 
build a reference UV Atlas of normal galaxies, whose optical images are 
well known, with the highest possible degree of information, covering all 
the morphological types and luminosity classes.  The proposal completed 
normally.

    1.16 Completed WF/PC-2/STIS/MA1 8686 (LINERs in Early-type Galaxies: 
Ionized by the UV-upturn Population?)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (MA1) were 
used to investigate the presence of extended ionized gas with LINER spectra 
in a large fraction {60-70%} of early-type galaxies.  The observations 
completed with no reported anomalies.

    1.17 Completed STIS/MA1 8843 (Cycle 9 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) was used to perform 
the routine monitoring of the MAMA detector dark noise.  The proposal 
completed nominally.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 14
Successful: 14

  Scheduled Re-acquisitions:  2
Successful:  2

    2.2 FHST Updates:
Scheduled: 34
Successful: 33

        The roll delay update scheduled for 205/155949Z failed due to error 
box results on tracker #2.  The subsequent full maneuver updates were 
successful.  HSTAR 8281 was written

    2.3 Operations Notes:

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

        The engineering status buffer limits were adjusted at 205/1600Z, 
using ROP DF-18A.

        Using ROP NS-3, the NSSC-1 status buffer was dumped and reset at 
205/1627Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW