HUBBLE SPACE TELESCOPE

   DAILY REPORT #2830

PERIOD COVERED:  0000Z (UTC) 03/15/01 - 0000Z (UTC) 03/16/01

Daily Status Report as of 075/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 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.

    1.2 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.

    1.3 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.

    1.4 Completed Two Sets of 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 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.

    1.6 Completed WF/PC-2 8583 (Imaging Snapshots of Asteroids)

        The WF/PC-2 was used to obtain images of the fifty largest main 
belt asteroids that have favorable apparitions during cycle 9.  The images 
will be searched for companion bodies, as well as mineralogical variegation 
on the resolved main bodies.  There were no reported problems.

    1.7 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.

    1.8 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.

    1.9 Completed STIS/CCD 8846 (Imaging Flats C9)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
investigate flat-field stability over a monthly period.  The proposal 
completed nominally.

    1.10 Completed STIS/CCD/MA1 8610 (A Black Hole Offset from the Host 
Galaxy Mass Center?)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
observe Seyfert galaxy, NGC2110, with its striking twin, that is a unique 
and valuable test case for the offset-nucleus phenomenon since, despite its 
remarkably normal rotation curve, its kinematically-measured mass center is 
displaced both spatially and kinematically from the active nucleus, as seen 
both in optical and radio studies.  However, the central kinematics, where 
the rotation curve rises most steeply, are inaccessible with ground-based 
resolutions.  The proposal completed with no problems.

    1.11 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.

    1.12 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.

    1.13 Completed Five 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.

    1.14 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.

    1.15 Completed WF/PC-2 8817 (Cycle 9 INTFLAT Sweeps and Linearity Test)

        The WF/PC-2 was used to obtain INTFLAT observations in order to 
monitor the pixel to pixel flatfield response and provide a linearity 
check.  The INTFLAT sequences, to be done once during the year, are similar 
to those from the Cycle 8 program 8448.  The images will provide a backup 
database in the event of complete failure of the VISFLAT lamp as well as 
allow monitoring of the gain ratios.  The sweep is a complete set of 
internal flats, cycling through both shutter blades and both gains.  The 
linearity test consists of a series of INTFLATs in F555W, in each gain and 
each shutter.  There was no anomalous activity.

    1.16 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.

    1.17 Completed Three 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.

    1.18 Completed STIS/MA2 8843 (Cycle 9 MAMA Dark Measurements)

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

    1.19 Completed STIS/MA2 8863 (NUV-MAMA Cycle 9 Flats)

        The Space Telescope Imaging Spectrograph (MA2) was used to obtain 
NUV-MAMA observations of the internal Deuterium lamp to construct an NUV 
flat applicable to all NUV modes.  There were no reported problems.

    1.20 Completed FGS/1R 8618 (Parallaxes of Magnetic CVs)

        FGS #1R was used to gather data for the calculation of 
trigonometric parallaxes of cataclysmic variable {CVs} which are needed to 
obtain reliable information on luminosities, accretion rates, and on radii 
and masses of the stellar components.  They are also needed to derive the 
space density, an important ingredient for theories of CV evolution.  The 
observations completed with no reported problems.

    1.21 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.

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: 13
Successful: 13

    2.3 Operations Notes:

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

        The SSR was configured for autonomous engineering recording on two 
occasions, using ROP SR-8A.

        A TTR was written for a required re-transmit at 074/203054Z during 
an NSSC-1 uplink.

        Using ROP NS-05, SI C&DH errors were reset at 074/2037Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW