HUBBLE SPACE TELESCOPE

   DAILY REPORT #2870

PERIOD COVERED:  0000Z (UTC) 05/10/01 - 0000Z (UTC) 05/11/01

Daily Status Report as of 131/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Two 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.

    1.2 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}.  The 
observations completed nominally.

    1.3 Completed 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 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 WF/PC-2 8723 (A Snapshot Survey of Galactic Globular 
Clusters)

        The WF/PC-2 was used to observe the crowded centers of globular 
clusters {GCs} that heretofore have produced intriguing discoveries of new 
phenomena, most of which are not understood theoretically.  The 
observations completed with no reported problems.

    1.6 Completed 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.

    1.7 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.

    1.8 Completed Two Sets of STIS/MA2 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.

    1.9 Completed WF/PC-2 8585 (Cosmological Parameters from Type Ia 
Supernovae at High Redshift)

        The WF/PC-2 was used to measure the cosmological parameters, Omega, 
Lambda, and thus the curvature, Omega_k, using Type Ia supernovae {SNe Ia} 
as calibrated standard candles.  There were no reported problems.

    1.10 Completed WF/PC-2 8712 (The Wind Accretion Wake In A Detached 
Binary System)

        The WF/PC-2 was used to observe RW Hya {= HD 117970}, the only 
known detached binary system, where direct observational evidence for wind 
accretion onto a white dwarf is found.  UV
observations will enable the investigator to advance knowledge in a field 
which has for long had to remain a theoretical subject.  RW Hya is an 
eclipsing system containing a mass-losing M-giant and a hot white dwarf on 
circular orbits {370 days}.  The observation completed with no reported 
problems.

    1.11 Completed 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.

    1.12 Completed WF/PC-2 8677 (Extragalactic Novae: the Maximum Magnitude 
- Rate of Decline Relation in NGC 4472)

        The WF/PC-2 was used to accomplish two goals: {1} to provide the 
first homogeneous observational constraints on theoretical models for novae 
outbursts; and {2} to assess the reliability of novae as standard candles 
by using WFPC2 to collect well sampled light curves for 20-50 novae in the 
supergiant elliptical galaxy NGC 4472, the brightest galaxy within 30 
Mpc.  Both the length of the observing window and the temporal sampling of 
the observations are specifically designed to ensure that the novae peak 
magnitudes and decline rates are measured accurately.  These data will be 
used to construct the first `Maximum Magnitude versus Rate of Decline' 
{MMRD} relation for a galaxy beyond the Local Group.  This relation is not 
only a potentially powerful standard candle, but its shape and dispersion 
are directly linked to physical parameters which govern the physics of 
novae outbursts such as the white dwarf mass, temperature and mass 
accretion rate.  The proposal completed with no reported problems.

    1.13 Completed 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.

    1.14 Completed WF/PC-2 8177 (Investigating Type Ia Supernovae and an 
Accelerating Universe)

        The WF/PC-2 was used to obtain rest frame U and B photometry for 
four z~ 0.85 Supernova (SN) Ia.  These observations will be coupled to 
ground-based rest frame V photometry and spectra.  These data, combined 
with previous samples, will extend the D_L vs. z diagram for SN Ia to 
z~0.85, and allow us to discriminate the redshift dependence of supernova 
magnitudes in an accelerating Universe from that expected to result from 
systematic effects such as age of the stellar population, chemical 
evolution, a drift in the properties of dust, and weak gravitational 
lensing.  The proposal completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  7
Successful:  7

  Scheduled Re-acquisitions:  9
Successful:  9

    2.2 FHST Updates:
Scheduled: 15
Successful: 15

    2.3 Operations Notes:

        ROP DF-05A was utilized to modify the telemetry diagnostic usage, 
restoring the MSS 1 and 2 Mag Field Squared values in slots 2 and 3.  This 
was done at 130/1406Z.

        The SSR EDAC error counter was cleared at 130/2337Z, using ROP SR-1A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW