HUBBLE SPACE TELESCOPE

   DAILY REPORT #2833

PERIOD COVERED:  0000Z (UTC) 03/20/01 - 0000Z (UTC) 03/21/01

Daily Status Report as of 080/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD 8591 (The Smallest Nuclear Black Holes)

        The Space Telescope Imaging Spectrograph (CCD) was used to observe 
small nuclear black holes which are the last major unexplored part of BH 
parameter space, searching for the smallest BHs that HST can possibly 
find.  The proposal completed with no reported anomalies.

    1.2 Completed Eight Sets of STIS/CCD 9248 (Probing the Large Scale 
Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the distortion of light bundles from distant galaxies that probe the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  Its tidal gravitational field distorts the observable image 
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}.  The 
observations completed nominally.

    1.3 Completed Two 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.

    1.4 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.

    1.5 Completed WF/PC-2 8719 (A Continuation Of A Snapshot Survey Of X- 
Ray Selected Central Cluster Galaxies0

        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.

    1.6 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

    1.7 Completed Three Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)

        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 nominally.

    1.8 Completed WF/PC-2 8581 (A Search For Low-Mass Companions To 
Ultracool Dwarfs)

        The WF/PC-2 was used to search for very low-mass {VLM} companions 
to a complete sample of 120 late-M and L dwarfs, drawn mainly from the 
2MASS and SDSS surveys.  The primary goal is to determine the multiplicity 
of M < 0.1 M_odot dwarfs.  In particular, we aim to identify binary systems 
suitable for long-term astrometric monitoring and mass measurement, and 
systems with cool, sub-1000K companions.  The proposal completed with no 
reported problems.

    1.9 Completed FGS/1 8774 (Calibrating the Mass-Luminosity Relation at 
the End of the Main Sequence)

        Fine Guidance Sensor #1 was used to calibrate the mass-luminosity 
relation {MLR} for stars less massive than 0.2 Msun, with special emphasis 
on objects near the stellar/brown dwarf border.  Our goals are to determine 
Mv values to 0.10 magnitude, masses to 5%, and more than double the number 
of objects with masses determined to be less than 0.20 Msun.  The proposal 
completed with no reported problems.

    1.10 Completed Three 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.  As described in HSTAR 8129 and 2.1, the 
acquisition for the final two iterations of this proposal defaulted to fine 
lock backup on one FGS only, possibly affecting the observations in those 
iterations.  Otherwise, the observations completed with no further 
anomalous activity.

    1.11 Completed Three Sets of STIS/MA1/MA2 8843 (Cycle 9 MAMA Dark 
Measurements)

        The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to 
perform the routine monitoring of the MAMA detector dark noise.  The 
proposal completed nominally.

    1.12 Completed STIS/CCD 8170 (Kinematics of the Young Star Clusters and 
the Gas in the Antennae Galaxies)

        The Space Telescope Imaging Spectrograph (CCD) was used to follow 
up on the previous discovery of over 1000 young star clusters in "The 
Antennae'' {NGC 4038} by obtaining long-slit and slitless spectra of a 
representative sample of clusters with STIS.  These young clusters have the 
luminosities, colors, and radii expected of young globular clusters and 
must have formed during the ongoing merger.  Because of their proximity and 
early stage of merging, the disks of NGC 4038 form an ideal laboratory to 
study cluster formation in progress.  The observations completed nominally.

    1.13 Completed WF/PC-2 8824 (Decontaminations and Associated 
Observations Pt. 3/4)

        The WF/PC-2 was used for the monthly WFPC2 decons.  Also included 
are instrument monitors tied to decons: photometric stability check, focus 
monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, 
UV throughput check, VISFLAT sweep, and internal UV flat check.  There were 
no reported problems.

    1.14 Completed STIS/CCD 8226 (Discerning the Origins of Blue 
Stragglers: Masses and Rotation Rates)

        The Space Telescope Imaging Spectrograph (CCD) was used to study 
the blue stragglers in globular cluster NGC-5272-BS.  Conventional wisdom 
holds that the masses of Blue Straggler Stars in globular clusters are 
significantly larger than the turnoff mass.  A wavelength calibration 
observation was also taken.  As described in HSTAR 8129 and 2.1, the 
acquisition for this proposal defaulted to fine lock backup on one FGS 
only, possibly affecting the observations in this proposal.  Otherwise, the 
observations were executed as scheduled, and no further anomalies were noted.

    1.15 Completed Two Sets of WF/PC-2 8816 (Cycle 9 UV Earthflats)

        The WF/PC-2 was used to obtain sequences of Earth streak flats to 
improve the quality of pipeline flat fields for the WFPC2 UV filter set and 
in order to monitor flat field stability. A s described in HSTAR 8129 and 
2.1, the acquisition for both iterations of this proposal defaulted to fine 
lock backup on one FGS only, possibly affecting all observations in this 
proposal.  Otherwise, there were no other reported problems.

    1.16 Completed Two Sets of WF/PC-2 8698 (Identification of the Galaxy's 
Missing Mass)

        The WF/PC-2 was used to observe the nature of dark matter that is 
one of the key astrophysical questions of the day.  The existence of dark 
matter and its dynamical dominance in the outer parts of our Galaxy and 
spiral galaxies with flat rotation curves is well established.  The MACHO 
project has identified ~half of the Milky Way's dark matter with stellar 
objects of ~0.5 M_sun, probably white dwarfs.  But the location of the 
microlensing in the halo is disputed.  Several have detected two candidate 
halo white dwarfs of L/L_sun ~ 10^-5 in the Hubble Deep Field with 25 +/- 5 
mas/year proper motions.  The observations completed with no reported problems.


2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  7
Successful:  7
  Scheduled Re-acquisitions:  8
Successful:  8

        Per HSTAR 8129, the acquisition at 079/140558Z defaulted to fine 
lock backup on FGS-3 only, as did the following re-acquisitions at 
079/153623Z and at 079/171247Z.  The proposals described in 1.10, 1.14 and 
1.15 may have been affected.


    2.2 FHST Updates:
Scheduled: 13
Successful: 13

    2.3 Operations Notes:

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

        ROP DF-18A was utilized twice to adjust the CCS engineering status 
buffer limits.

        A TTR was written when there was a generic command drop-out at 
080/073039Z during a command load uplink.  The re-transmit was successful.

        There was a STIS EMC re-try at 080/072519Z.  The STIS flight 
software error counter was reset at 080/0741Z per ROP NS-12.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW