HUBBLE SPACE TELESCOPE

   DAILY REPORT #2848

PERIOD COVERED:  0000Z (UTC) 04/10/01 - 0000Z (UTC) 04/11/01

Daily Status Report as of 101/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Two 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.

    1.2 Completed STIS/CCD/MA2 8621 (The Galactic Abundance Gradients of 
Boron and Iron)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
provide the first measurement of the Galactic abundance gradients for Boron 
and Iron.  Boron abundances were obtained for 5 B-type stars {with 
Galactocentric distances between 4-15 kpc} from the BIII 2066 Angstrom 
line.  Optical spectroscopy of these {and other B-type} stars has yielded 
abundance gradients of -0.07 dex/kpc for N & the Alpha-elements {O, Mg, 
Si}.  Determination of Boron abundances require UV spectra.  The proposal 
completed nominally.

    1.3 Completed Four 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.

    1.4 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 8639 (The Origin of Gaseous Outflows in Active 
Galaxies)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
images, previously observed by WF/PC-2, of the ionized gas in the Circinus 
galaxy, a nearby Seyfert 2.  The previous images reveal that the nuclear 
high excitation gas is ``V-shaped'' and represents the inner part of the 
``ionization cone'' seen previously on much larger scales in ground-based 
observations. These images suggest that the observed emission lies along 
the boundary of a conical structure, a situation which has probably 
originated through mass entrainment of dense gas in the galaxy disk along 
the edges of a low density outflow.  The proposers wish to obtain long slit 
observations of this structure.  The goals are: 1} to confirm or reject 
this picture kinematically; 2} investigate how gas is entrained into the 
outflow from the dense ism in the galaxy disk in the inner region of the 
outflow at unprecedented spatial resolution for a Seyfert galaxy {our 
resolution of 1 pc is comparable to or smaller than the expected radius of 
the inner edge of the putative blocking ``torus''}; 3} distinguish between 
collimation of ionization photons or of gaseous outflow as the origin of 
the "ionization cone''; and 4} attempt to measure the mass of the nuclear 
black hole using a long slit spectrum of the disk HII regions.  The 
observations completed with no reported problems.

    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 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.

    1.8 Completed WF/PC-2 8883 (POMS Test Proposal: WFII Backup Parallel 
Archive Proposal II)

        The WF/PC-2 was used to complete a POMS test proposal designed to 
simulate scientific plans.  There were no reported problems.

    1.9 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.

    1.10 Completed WF/PC-2 8563 (Determining the Duplicity of Nearby T 
Dwarfs {Methane Brown Dwarfs})

        The WF/PC-2 was used to investigate the binary fraction of T-type 
dwarfs {methane brown dwarfs} which is crucial to accurate determinations 
of the T-dwarf space density and mass function, especially since equal- 
magnitude binaries can introduce significant biases in photometric distance 
estimates.  The proposal completed nominally.

    1.11 Completed Six 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.

    1.12 Completed WF/PC-2/STIS/CCD 8568 (A Seminal Spectroscopic and 
Imagery Investigation of the Brightest Wolf-Rayet Shell Nebula: NGC 6888)

        The WF/PC-2 (for imagery) and the Space Telescope Imaging 
Spectrograph (CCD for UV-optical-NIR spectroscopy of several regions in the 
brightest Wolf-Rayet Shell) were used to observe Nebula {WRSN}, NGC 
6888.  The physical conditions in the wind-driven and/or stellar ejected 
plasma {temperature, density, ionization, and composition} of WRSN, which 
are dominated by strong stellar winds from hot massive stars in an advanced 
state of evolution, often involve emission from both shock-ionized and 
photoionized gas in close proximity.  These new observations will comprise 
the first combined spectroscopy and imagery of a WRSN at a resolution 
sufficient to separate and individually analyze these two emission 
regions.  The proposal completed nominally with no reported problems.

    1.13 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.  There were no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  9
Successful:  9

  Scheduled Re-acquisitions:  8
Successful:  8

    2.2 FHST Updates:
Scheduled: 15
Successful: 15

    2.3 Operations Notes:

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

        Using ROP NS-3, the NSSC-1 status buffer was dumped at 100/1446Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW