HUBBLE SPACE TELESCOPE

   DAILY REPORT #2923

PERIOD COVERED:  0000Z (UTC) 07/26/01 - 0000Z (UTC) 07/27/01

Daily Status Report as of 208/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Three 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.  The proposal completed nominally.

    1.2 Completed Nine 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.

    1.3 Completed Two 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.

    1.4 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 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.

    1.6 Completed Two 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.

    1.7 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.

    1.8 Completed Two Sets of 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.

    1.9 Completed WF/PC-2 9160 (Disks and Envelopes of Nearby Nebulous 
Young Stellar Objects: A Snapshot Survey)

        The WF/PC-2 was used to perform a snapshot survey of nearby 
nebulous young stellar objects to study the detailed morphology of the 
their disks and envelopes and probe the effect of inclination on the 
infrared spectral energy distribution of disk/envelope systems.  The 
proposal completed as planned.

    1.10 Completed WF/PC-2 8719 (A Continuation Of A Snapshot Survey Of X- 
Ray Selected Central Cluster Galaxies)

        The WF/PC-2 was used to perform snapshot images of a representative 
subset of the central cluster galaxies from an X-ray selected cluster 
sample that would provide important constraints on the formation and 
evolution of dust in cluster cores that cannot be obtained from 
ground-based observations.  The observations completed as planned.

    1.11 Completed WF/PC-2 8601 (A Snapshot Survey of Probable Nearby Galaxies)

        The WF/PC-2 was used to continue the very successful snapshot 
survey in order to use the high spatial resolution of HST to determine 
whether selected galaxies are nearby on the basis of resolution into stars, 
and the magnitudes and colors of the brightest stars.  There were no 
reported problems.

    1.12 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.

    1.13 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.

    1.14 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.

    1.15 Completed WF/PC-2/STIS/CCD 8559 (The Role of Dark Matter in 
Cluster Formation and Galaxy Evolution)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were 
used to observe the outer regions of massive clusters that represent 
transitional areas of great cosmological importance where field galaxies 
encounter the steep potential wells of dark matter and baryonic hot 
gas.  Little is known about either the dark matter profile at large radii 
or the morphological properties of infalling galaxies at those redshifts 
where strong evolution is observed in the cluster cores.  The proposal 
completed normally, with no reported problems.

    1.16 Completed WF/PC-2 8683 (Imaging Of Brightest Cluster Galaxies: The 
High End Of The Black Hole Mass Distribution)

        The WF/PC-2 was used to make kinematic black hole detections in 
galaxies to decide whether they indicate that the mass correlates with both 
optical luminosity and radio power.  The observation completed with no 
reported problems.

    1.17 Completed STIS/CCD 9246 (POMS Test Proposal: Non-scripted Parallel 
Proposal Continuation IV)

        The Space Telescope Imaging Spectrograph (CCD) 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.

    1.18 Completed Two Sets of 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.  The proposal completed uneventfully.

    1.19 Completed WF/PC-2 9163 (Kinematics Of Emission-Line Gas Disks In 
Radio-Quiet Galaxies)

        The WF/PC-2 was used to measure central black hole {BH} masses from 
the rotation rate of the emission-line gas, and to determine the nature and 
structure of the gas disks. Three galaxies with no radio jets and with 
Halpha+[NII] emission have been identified, which have dust disks similar 
to those commonly seen in our sample of radio-loud active galaxies.  All 
observations completed nominally.

    1.20 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.

    1.21 Completed WF/PC-2 9149 (The Nature Of The Most Luminous Star- 
Forming Galaxies In The Redshift Range 0.4 To 1.5)

      The WF/PC-2 was used to perform additional ISO deep surveys that have 
previously uncovered a population of galaxies which are making stars at the 
fantastic rate of > 100 M_odotyr^-1 in the redshift range from 0.4 to 
1.5.  However this population evolves rapidly and luminous star-forming 
galaxies are 5 to 10 times more numerous at z=1 than today.  Combination of 
ISO data with radio {VLA}, sub-mm {SCUBA} and optical data shows that they 
contribute a major fraction {30-50$ representing only a few percent of the 
field galaxy population.  HST imaging of a small subsample of these 
galaxies indicates that most of them are disks showing disrupted 
morphologies or possessing companions, emphasizing the role of merging in 
their star formation history.  The proposal completed without incident.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 12
Successful: 12

  Scheduled Re-acquisitions:  6
Successful:  6

    2.2 FHST Updates:
Scheduled: 24
Successful: 22

        Per HSTAR 8284, the full maneuver updates scheduled for 207/192139Z 
and at 207/192424Z due to tracker #3.  The following acquisition was 
successful.

    2.3 Operations Notes:

        Upon the conclusion of GSFC Internal Simulation #11 (EVA-5), 
real-time operations returned to CCS string "A" at 207/2150Z.

        Using ROP SR-1A, the SSR EDAC error counter was cleared on two 
occasions.

        A TTR was generated when, at 207/110816Z, a SAA forward/return 
service was 30 seconds late due to a short turn-around from another 
critical spacecraft support.  There was no data loss.

        The 486 status buffer limits were adjusted at 207/1925Z per ROP DF-18A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW