HUBBLE SPACE TELESCOPE

   DAILY REPORT #2846

PERIOD COVERED:  0000Z (UTC) 04/06/01 - 0000Z (UTC) 04/09/01

Daily Status Report as of 099/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 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.

    1.2 Completed Seven 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.

    1.3 Completed Two Sets of WF/PC-2 8599 (A Census of Nuclear Star 
Clusters in Late-Type Spiral Galaxies)

        The WF/PC-2 was used to conduct an I-band snapshot survey of a 
well-defined sample of nearby, face-on spiral galaxies of type Scd or 
later.  The proposal completed nominally.

    1.4 Completed Seven 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.

    1.5 Completed Six 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 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.

    1.7 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.

    1.8 Completed Eight 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.

    1.9 Completed Three Sets of STIS/CCD 8624 (Imaging and Spectroscopy of 
Dusty Circumstellar Disks)

        The Space Telescope Imaging Spectrograph (CCD) was used to further 
understanding of the properties and evolution of dusty disks in the 
circumstellar environments of young stars which is a key element in 
furthering our concepts of the formation mechanisms of extra-solar 
planetary systems.  The proposal completed with no reported problems.

    1.10 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.

    1.11 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.

    1.12 Completed WF/PC-2 8867 (Gamma-Ray Bursts: Discovering The 
Progenitors And Understanding The Explosion - Visits A0-R0)

        The WF/PC-2 was used to observe a 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.

    1.13 Completed Five Sets of STIS/CCD 8851 (Sparse Field CTE test {Cycle 9})

        The Space Telescope Imaging Spectrograph (CCD) was used to perform 
CTE measurements that are made using the "sparse field test", along both 
the serial and parallel axes.  The proposal completed with no reported 
anomalies.

    1.14 Completed Four Sets of WF/PC-2 8888 (Heritage Observations of ESO 
510-13)

        The WF/PC-2 was used to perform heritage observations of galaxy ESO 
510-13, a galaxy with a warped disk.  The proposal completed with no 
reported problems.

    1.15 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.

    1.16 Completed Three Sets of STIS/CCD 8841 (Hot Pixel Annealing C9)

        The Space Telescope Imaging Spectrograph (CCD) was used to improve 
the effectiveness of the CCD hot pixel annealing process.  This is assessed 
by measuring the dark current behavior before and after annealing and by 
searching for any window contamination effects.  In addition CTE 
performance is examined by looking for traps in a low signal level 
flat.  The observations completed with no reported problems.

    1.17 Completed FGS/1 8730 (The Masses of the O-type Binary 15 Monocerotis)

        Fine Guidance Sensor #1 was used to investigate the O-type star 15 
Mon {HD 47839} that was recently discovered to be an astrometric and 
spectroscopic binary with an orbital period of 25 years.  It is the first 
known O-star system to bridge the observational gap between the period 
regimes normally probed by these techniques.  The proposal completed nominally.

    1.18 Completed Three Sets of 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.

    1.19 Completed WF/PC-2 8773 (Expansion Parallax Distances to Planetary 
Nebulae)

        The WF/PC-2 was used to observe planetary nebulae {PNe} for which 
the lack of reliable distances is especially troubling.  Acquired by 
generalized statistical methods in all but a handful of cases, individual 
PNe distances are often uncertain by factors of two or more.  The 
observations completed nominally.

    1.20 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.

    1.21 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.

    1.22 Completed Two Sets of WF/PC-2/STIS/CCD 8679 (Constraining the Age 
of the Oldest Stars from the White Dwarf Cooling Sequence in M4)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were 
used to search for the oldest and hence coolest white dwarfs {WDs} in M4, 
the nearest Galactic globular cluster to the Sun.  New models for cooling 
hydrogen white dwarfs predict that their colors should become bluer, rather 
than redder, with increasing age. The goal is to test these models and at 
the same time constrain the age of M4.  The proposal completed with no 
problems.

    1.23 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.

    1.24 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.

    1.25 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.

    1.26 Completed STIS/CCD/MA2 8628 (High Density {~ 10^9 Cm^-3} Gas In 
The Jet Formation Region Of T Tauri Stars)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
investigate the ubiquitous outflow that occurs during star formation for 
which the driving mechanism is still unknown.  The proposal intends to 
compare the kinematics of the UV line formation region with that of the 
optical forbidden lines and to determine the physical characteristics of 
the jet formation region.   There were no reported problems.

    1.27 Completed WF/PC-2 8645 (A Survey of Mid-UV Morphology of Nearby 
Galaxies: Galaxy Structure and Faint Galaxy)

        The WF/PC-2 was used to investigate the relation between star 
formation and the global physical characteristics of galaxies to interpret 
the morphologies of distant galaxies in terms of their evolutionary 
status.  The observations completed nominally.

    1.28 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.

    1.29 Completed Two Sets of STIS/CCD 8674 (Coronographic Imaging Of Old 
PMS Stars)

        The Space telescope Imaging Spectrograph (CCD) was used to to 
investigate the missing link between MS and young stars CS environments by 
searching for second generation disks of dust or gas around the few known 
old PMS stars and by modeling their CS environments.  Our
HST/NICMOS images revealed a disk around HD141569, and possibly also {but 
still to be confirmed} around HD100546 and HD135344.  We propose here to 
use the unprecedented detection capabilities of STIS to get high 
signal-to-noise {SN} images of HD141569 and HD135344.  This will allow to 
study in much more detail the HD141569 disk, to confirm or infirm the other 
disk, and to perform fine modeling of the CS dust.  The proposal completed 
with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 29
Successful: 29

  Scheduled Re-acquisitions: 19
Successful: 19

    2.2 FHST Updates:
Scheduled: 54
Successful: 54

    2.3 Operations Notes:

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

        SSA transmitter #1 was turned on and off at 096/1639Z per ROP IC-2.

        A TTR was written for a one-minute, 35-second unrecoverable loss of 
engineering data beginning at 096/1640Z.  The NCC had to re-set its 
equipment when a Mode 1 GCMR was not received at STGT.  Another TTR was 
filed for 30 minutes of unrecoverable loss of engineering data beginning at 
096/1445Z when STGT did not get a schedule change.

        HSTAR 8153 documents the fact that the parameter QDSCOSE (the earth 
point cosine) flagged out-of-limits high with a value of 0.312797 at an 
angle of 71.8 degrees at 098/033529Z.  No safing test failed.

        There was a STIS EMC entry at 098/032647Z.  The STIS flight 
software error counter was cleared at 098/0431Z as directed by ROP NS-12.

        The STIS MCE-2 reset at 098/135016Z while the low voltage was on 
and while inside an SAA interval.  Using ROP NS-12, the STIS flight 
software error counter was cleared at 098/1420Z.  MAMA-2 was recovered via 
normal SMS commanding at 099/0739Z.

        A TTR was written for a one-minute, 30-second unrecoverable loss of 
engineering data at 098/1940Z due to a return service drop-out.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW