HUBBLE SPACE TELESCOPE

   DAILY REPORT #2869

PERIOD COVERED:  0000Z (UTC) 05/09/01 - 0000Z (UTC) 05/10/01

Daily Status Report as of 130/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed WF/PC-2 8702 (The Most Elusive Nuclei of LMC Planetary 
Nebulae)

        The WF/PC-2 was used to carry out a SNAPSHOT survey of the faintest 
nuclei of planetary nebulae {PNe} in the LMC.  This program will be a 
crucial follow-on to a Cycle 8 SNAPSHOT of LMC Pne.  In thisa case the plan 
is to observe the faintest or most obscured nuclei to determine their 
evolutionary state to an accuracy not possible in the Galaxy.  These 
faintest central stars are predicted to be among the most massive nuclei, 
and owing to the typically advanced age of the surrounding nebulae, are the 
most sensitive discriminants for validating the post-AGB evolution 
timescales predicted by theory.  The observations completed with no 
reported problems.

    1.2 Completed Eleven 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}.  As 
detailed in 2.1 and HSTAR 8212, the acquisition for the ninth iteration of 
this proposal failed, affecting one observation when the take data flag 
remained down.  Otherwise, the observations completed nominally.

    1.3 Completed Four Sets of WF/PC-2 8828 (Cycle 9 Supplemental Darks pt3/3)

        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 with no reported problems.

    1.4 Completed Four 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.

    1.5 Completed FGS/1 9240 (Astrometric Mass Determination of an 
Extrasolar Planet Candidate)

        Fine Guidance Sensor-1R was used to perform astrometric 
observations that will allow a quick measure of the sky-plane motion of 55 
Cancri, a G star with an Msin{i} = 0.9 MJ radial velocity companion with a 
14 day period.  By using 7 pairs of visits, where each visit within a pair 
has the same parallax factor, we will be able to accurately determine the 
stars's proper motion.  The reflex motion of the star, due to its orbit 
about the star-companion barycenter, will manifest itself as a systematic 
residual to the measured proper motion if the companion is sufficiently 
massive.  There were no reported problems.

    1.6 Completed Three 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.

    1.7 Completed Three Sets of 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.

    1.8 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.

    1.9 Completed WF/PC-2 8719 (A Continuation Of A Snapshot Survey Of X- 
Ray Selected Central Cluster Galaxies)

        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.

    1.10 Completed 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.

    1.11 Completed STIS/CCD/MA1 8620 (Taking A Glance At The Beating Heart 
Of 4 Draconis)

        The Space Telescope Imaging Spectograph (CCD and MA1) was used to 
observe 4 Dra, which is a unique triple system containing a magnetic 
cataclysmic variable {AM Her-type} and an M3 III giant.  Even though the 
M-giant completely dominates the optical emission of the system, we can 
learn much from 4 Dra about the accretion physics in and the evolution of 
AM Her stars, because: {a} 4 Dra is the second brightest AM Her star in the 
ultraviolet, {b} 4 Dra is one of the very few cataclysmic variables with a 
good HIPPARCOS parallax {d~180 pc}, and, in addition, {c} 4 Dra is so far 
the only bright CV for which an estimate of the age, ~10^8 yrs could be 
derived.  We propose an in-depth HST/STIS echelle study of the AM Her star 
in 4 Dra.  Our scientific goals are twofold. {1} We will derive the 
fundamental properties of the accreting magnetic white dwarf, such as its 
photospheric temperature, the temperature and the size {lateral extent} of 
the accretion-heated pole cap, and the chemical composition of the 
accretion-enriched atmosphere. {2} We will use the HST/STIS echelle spectra 
for Doppler mapping of the UV line emission.  The observations completed 
without reported incident.

    1.12 Completed STIS/CCD 8611 (Observations of Nearby Type Ia Supernovae)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
UV spectra of five nearby {0.02 < z < 0.08} SNe Ia in the Hubble Flow.  The 
spectra will be taken at weekly intervals over a range in time starting 
slightly before maximum light and extending to +30 days.  These 
observations will accomplish the following three goals: {1} calibration of 
the rest frame UV light curves of SNe Ia and an assessment of their 
potential use as distance indicators through UV light curve shape analyses. 
{2} improvement in our understanding of the physics of SNe Ia, 
metallicity/evolutionary effects and correlations between peak brightness 
and UV spectral features. {3} calibration of the SNe Ia previously observed 
by HST at high-redshift.  This data is crucial for proper cross-filter 
k-corrections and calibration of the supernova photometry.  The 
observations completed with no reported anomalous activity.

    1.13 Completed WF/PC-2/STIS/CCD 8675 (The Massive Star Content of NGC 6822)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were 
used to characterize the young, coeval stellar population discovered with 
WFPC2 multiband imaging in a NGC6822 star-forming region, with follow-up 
spectroscopy of the massive star candidates.  The proposal completed with 
no reported problems.

    1.14 Completed Two Sets of WF/PC-2 8604 (Stellar Populations Across the 
Small Magellanic Cloud (SMC): History and Structure)

        The WF/PC-2 was used to investigate the structure and evolutionary 
history of the SMC by obtaining a series of 50 three-color snapshots of 
selected SMC regions.  With this polling of SMC field star properties, we 
will produce color-magnitude diagrams in the U, V and I bands which will 
reach V~23.5 in regions too crowded to be observed accurately from the 
ground.  As detailed in 2.1 and HSTAR 8212, the acquisition for the second 
iteration of this proposal failed, affecting three observations when the 
take data flag remained down.  Otherwise, the observations completed nominally.

    1.15 Completed Two Sets of WF/PC-2 8682 (A Snapshot Study of 
0bservational Cosmology)

        The WF/PC-2 was used to examine the observational constraints on 
the cosmic star formation history that is currently among the most active 
fields in observational cosmology.  The most widely used tracer of the 
co-moving volume-averaged star formation rate {SFR} is the UV luminosity 
density, which early results found to peak at z~1- 2.  The apparent 
identification of the primary epoch of metal production and star formation 
in the Universe led to intense theoretical and observational 
interest.  Nevertheless, and remarkably for such a fundamental observation, 
little is known about the history of star formation in the Universe beyond 
its global average.  There were no reported anomalies.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 13
Successful: 12

        Per HSTAR 8212, the acquisition at 129/215514Z failed to RGA 
control when the search radius limit was exceeded on FGS-3.  The following 
acquisition was successful.  The proposals described in 1.2 and 1.14 were 
affected.
  Scheduled Re-acquisitions:  2
Successful:  2

    2.2 FHST Updates:
Scheduled: 22
Successful: 22

    2.3 Operations Notes:

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

        The CCS status buffer limits (related to acquisition failure 
detailed above) were adjusted at 129/2235Z, using ROP DF-18A.

        HSTAR 8214 documents the MTE 3A Mag Bar Volts (GMT3AMBV) flagged 
out-of-limits with a value of -15.84 from 130/044213Z until 130/044216Z, 
from 130/044301Z until 130/044304Z, from 130/044449Z until 130/044452Z, and 
from 130/044458Z until 130/044501Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW