HUBBLE SPACE TELESCOPE

  DAILY REPORT #2819

PERIOD COVERED:  0000Z (UTC) 02/28/01 - 0000Z (UTC) 03/01/01

Daily Status Report as of 060/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Five 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 Two Sets of STIS/CCD 8837 (CCD Dark Monitor-Part 1)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks.  The proposal completed with no reported problems.

    1.3 Completed Two Sets of 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.

    1.4 Completed STIS/CCD/MA1 8606 (Determining the Nature of the Variable 
Absorption in AGN: Monitoring NGC 3783 with HST And Chandra)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
investigate Seyfert 1 galaxies, many of which show intrinsic UV absorption 
lines, characterized by high moderate widths, significant outflow 
velocities, and variability on time scales as small as days.  Seyferts with 
UV absorption also show variable X-ray ``warm absorbers'', characterized by 
O VII and O VIII absorption edges, which suggests a common 
origin.  Variability monitoring is the key to understanding the absorbers, 
by providing their radial locations, densities, and evolution in 
ionization, column density, velocity, and coverage of the inner active 
nucleus.  The proposal completed with no problems.

    1.5 Completed Six Sets of WF/PC-2 8805 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
WFPC2 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 proposal completed with no reported 
problems.

    1.6 Completed 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.

    1.7 Completed STIS/MA1 8721 (An UV Imaging Survey of IR-Bright Star- 
Forming Galaxies)

        The Space Telescope Imaging Spectrograph (MA1) was used to carry 
out a UV {~1, 600 Angstrom} snapshot imaging survey of all the actively 
star-forming galaxies detected by ISO at Lambda>170 Mum and closer than 
cz=9000 km/s.  The sample covers a large region in the parameter's space of 
morphology, luminosity, metallicity, and star formation intensity.  There 
were no reported anomalies.

    1.8 Completed Seven Sets of STIS/CCD 8562 (Probing the Large Scale 
Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to probe 
the distortion of light bundles from distant galaxies, looking at the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  The proposal completed nominally.

    1.9 Completed FGS-1R 8783 (Orbits of Pre-Main Sequence Binaries)

        FGS-1R was used to dynamically measure the masses of low mass 
pre-main sequence stars.  This is important because there are still no low 
mass young stars with reliably known masses.  In cycle 5 we began to map 
the orbits of young multiple star systems in Taurus using FGS3.  It is 
proposed to continue to measure the orbits of the binary and triple systems 
that have been determined to have the smallest angular separations with the 
more capable FGS-1R.  The proposal completed with no reported problems.

    1.10 Completed FGS/1R 8777 (Calibrating Stellar Models with the 
Pleiades: Resolving the Distance Discrepancy-Cycle 9)

        FGS-1R was used to measure an accurate distance to the Pleiades and 
to resolve the problem raised by the Hipparcos results for this 
cluster.  The Hipparcos distance, taken at face value, indicates that 
solar-composition ZAMS stars are 30% fainter than previously believed.  The 
resolution to the Hipparcos distance problem is vital for understanding all 
the parallaxes that have come from that mission and hence this issue is 
fundamental to the cosmic distance scale. In this first phase we observed 
several spectroscopic binary systems with 2 to 3 year orbital periods to 
assertain the prospects for deriving visual orbits and hence orbital 
parallaxes for these cluster members.  The proposal completed with no 
reported problems.

    1.11 Completed FGS/1R 8832 (Long Term Monitoring in Position Mode)

        Fine Guidance Sensor-!R was used to observe the relative positions 
of stars in a standard cluster at a fixed telescope pointing and 
orientation coordinates.  The evolution of rhoA and kA were monitored and 
calibrated to preserve the astrometric integrity of the FGS.  It is well 
known for our experience with FGS3, and later with FGS1r, that an FGS 
experiences long term evolution, presumably due to disorption of water from 
the instrument's graphite epoxy composites.  This manifests principally as 
a change in the plate scale and secondarily as a change in the 
distortions.  The proposal completed nominally, with no reported problems.

    1.12 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.

    1.13 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.

    1.14 Completed WF/PC-2 8598 (Snapshot Survey of Extended OIIl Lambda 
5007Angstrom Emission in Seyfert Galaxies)

        The WF/PC-2 was used for a snapshot survey of narrow band OIII 
Lambda 5007Angstrom images for a well defined sample of 88 Seyfert galaxies 
{29 Seyfert 1s and 59 Seyfert 2s}, 18 of which already have data in the 
archive, selected from a mostly isotropic property, the 60Mum flux.  These 
data will be used: 1} to determine the origin of the misalignment between 
the accretion disk axis and the host galaxy plane axis, which can be due to 
mergers with other galaxies, or by the self induced radiation warping; 2} 
to compare the size and shape of the Narrow Line Regions (NLR) of Seyfert 
1s and Seyfert 2s, and to study the frequency of conically shaped NLR in 
Seyfert galaxies, which are usually unresolved from ground-based 
observations; and 3} estimate the importance of shocks to the ionization of 
the NLR.  The observations completed with no reported problems.

    1.15 Completed STIS/CCD 8838 (Bias Monitor - Part 1)

        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 nominally.

    1.16 Completed WF/PC-2 8867 (Gamma-Ray Bursts: Discovering The 
Progenitors And Understanding The Explosion)

        The WF/PC-2 was used to observe a target-of-opportunity gamma-ray 
burster, GRB010222.  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.

    1.17 Completed STIS/CCD/MA1 8638 (Temperature Scale And Metal 
Abundances Of Hot Hydrogen-Rich Central Stars Of Planetary Nebulae)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
perform UV spectroscopy on a sample of hot hydrogen-rich central stars of 
PNe, covering the hottest phase of post-AGB evolution. The spectra will 
then be analyzed with fully metal line blanketed NLTE model atmospheres in 
order to determine T_eff, surface gravity, and chemical composition.  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:  6
Successful:  6

    2.2 FHST Updates:
Scheduled: 23
Successful: 23

    2.3 Operations Notes:

        Using ROP SR-1A, the SSR EDAC error counter was cleared three times.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW