HUBBLE SPACE TELESCOPE

   DAILY REPORT #2814

PERIOD COVERED:  0000Z (UTC) 02/21/01 - 0000Z (UTC) 02/22/01

Daily Status Report as of 053/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD/MA2 8770 (The Nucleosynthesis of Boron - 
Benchmarks for the Galactic Disk)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
determine boron (B) abundance.  In spite of several HST cycles of B 
abundance determinations, we do not know the true, ambient, present-day 
abundance of B.  Only two stars {with undepleted Li and Be} have been 
observed to derive the Population I true B abundance.  Past cycles have 
focused on {1} halo stars with low metallicity and {2} solar-type stars 
with Li and/or Be deficiencies.  In this proposal, the stellar abundances 
of B will be determined, measured from the B I 2497 Angstrom line from STIS 
echelle spectra, of main sequence F-G stars that have retained their full 
initial abundances of boron.  Our target stars are those for which 
ground-based observations show that beryllium is undepleted.  These new 
abundances will map evolution of the B abundance in the Galactic disk in 
the metallicity range from one-third solar up to solar.  Then the B, and 
previously determined Li and Be abundances, will be used to improve 
understanding of the nucleosynthesis of B.  There were no reported anomalies.

    1.2 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.

    1.3 Completed WF/PC-2 8812 (Cycle 9 Internal Monitor)

        The WF/PC-2 was used to obtain routine internal monitors for WFPC2 
in order to monitor the health of the cameras.  A variety of internal 
exposures are obtained in order to provide a monitor of the integrity of 
the CCD camera electronics in both bays {gain 7 and gain 15}, a test for 
quantum efficiency in the CCDs, and a monitor for possible buildup of 
contaminants on the CCD windows.  There were no reported problems.

    1.4 Completed STIS/CCD/MA1 8662 (A Snapshot Survey of the Hot 
Interstellar Medium)

        The Space Telescope Imaging Spectrograph (CCD And MA1) was used to 
obtain snapshot STIS echelle observations of key tracers of hot 
interstellar gas {C IV, N IV, and Si IV} for selected FUSE Team O VI survey 
targets with known UV fluxes.  By taking advantage of the snapshot 
observing mode we will efficiently obtain a large number of spectra 
suitable for the study of the highly ionized hot component of the 
interstellar medium {ISM}.  Our goals are to explore the physical 
conditions in and distribution of such gas, as well as to explore the 
nature of the interfaces between the hot ISM and the other interstellar gas 
phases.  The observations completed with no reported problems.

    1.5 Completed Ten 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.

    1.6 Completed Two Sets of WF/PC-2 8600 (Dwarf Elliptical Galaxy 
Snapshot Survey III)

        The WF/PC-2 was used to extend our V and I snapshot survey of 
nearby dwarf elliptical {dE} galaxies to include a sample of 30 bright dE 
with significant globular cluster {GC} populations.  There were no reported 
problems.

    1.7 Completed Three 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.

    1.8 Completed WF/PC-2 8720 (Masses and Multiplicity of Nearby Free- 
floating Methane and L Dwarfs)

        The WF/PC-2 was used to observe 50 very-low-mass objects in the 
solar neighborhood with spectral types of L0 and later {including several 
dwarfs with Methane absorption bands in their atmospheres}.  These objects 
will be observed in two filter bands with the aim to identify close 
companions, measure their colors, and to obtain first epoch data of the 
newly discovered binaries.  The observations completed nominally.

    1.9 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.

    1.10 Completed WF/PC-2 7407 (Continuation of Temporal Monitoring of the 
Crab Synchrotron Nebula)

        The WF/PC-2 was used to observe the synchrotron nebula surrounding 
the Crab pulsar that has been the subject of intensive study for 
decades.  It is generally accepted that the structure and activity in this 
region are due to wave phenomena near the termination shock of the pulsar 
wind, observations of which hold unique promise of leading to more complete 
models of the pulsar and its magnetosphere.  Unfortunately, this promise 
has not been fulfilled, largely because of the low spatial resolution and 
uneven temporal coverage of existing studies.  Recent WF/PC-2 observations 
of the Crab synchrotron nebula offer new hope in this quest.  These data, 
which reach the natural size scale defined by the Larmor radius of 
energetic electrons, resolve the majority of the known features in the 
Crab.  For the first time it is possible to reliably establish the physical 
conditions {e.g., emissivities, equipartition fields, and pressures} of 
features associated with the wind and its termination shock.  The 
observations completed as planned.

    1.11 Completed WF/PC-2 8705 (External Shear in the Time-Delay Lens RX 
J0911+05)

        The WF/PC-2 was used to map the mass distribution in the vicinity 
of the multiple QSO system RX J0911+05 using weak gravitational 
lensing.  This object has emerged as one of the most promising candidates 
for a cosmological determination of the Hubble constant using time delay 
measurements.  There is evidence that a high-redshift cluster of galaxies 
acts as the source of a very large external shear, affecting the lens 
potential.  Deep WFPC2 images will allow direct measurement of this shear 
from the distortions of faint background galaxies.  The proposal completed 
with no reported problems.

    1.12 Completed Four 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.

    1.13 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.

    1.14 Completed STIS/CCD/MA2 8627 (Testing Theories Of Wind/Jet 
Production In YSOs)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
test theories of jet/wind production from the accretion disks of low-mass 
young stellar objects, providing new insight into disk physics, accretion 
energy balance, and jet collimation.  Observations of the Fe II ultraviolet 
lines in absorption will probe lower-density and lower-temperature material 
than optical forbidden and permitted emission lines, and thus provide 
unique information on jet/wind launching and 
acceleration.  Velocity-resolved spectra will distinguish between X-wind 
models, in which all the mass ejection occurs from the inner disk edge, and 
disk wind models, where the flow originates from a much larger area of the 
disk.  The MCE-2 reset described in 2.3 occurred approximately 
three-quarters through this approximate four-hour proposal, possibly 
affecting some of the science.  Otherwise, the proposal completed 
nominally, with no further anomalous activity.

    1.15 Completed 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.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  8
Successful:  8

  Scheduled Re-acquisitions:  6
Successful:  6

    2.2 FHST Updates:
Scheduled: 17
Successful: 17

    2.3 Operations Notes:

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

        The STIS MCE-2 reset at 053/011037Z while the high voltage was on 
but while outside any SAA interval.  MAMA-2 was recovered via normal SMS 
commanding at 053/0115Z.  The proposal described in 1.14 may have been 
affected.  The STIS flight software error counter was cleared at 053/0128Z 
per ROP NS-12.

        The NSSC-1 status buffer was dumped and reset at 053/0517Z as 
directed by ROP NS-3.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW