HUBBLE SPACE TELESCOPE

  DAILY REPORT #2860

PERIOD COVERED:  0000Z (UTC) 04/26/01 - 0000Z (UTC) 04/27/01

Daily Status Report as of 117/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed WF/PC-2 8059 (POMS Test Proposal: Targeted Parallel 
Archive Proposal)

        The WF/PC-2 was used to observe the parallel opportunities 
available in the neighborhood of bright galaxies are treated in a slightly 
different way from the normal pure parallels.  Local Group galaxies offer 
the opportunity for a closer look at young stellar 
populations.  Narrow-band images in F656N can be used both to identify 
young stars via their emission lines, and to map the gas distribution in 
star-forming regions.  The observations completed nominally.

    1.2 Completed Five 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 FGS/1 8731 (A High Angular Resolution Survey of the Most 
Massive Stars in the SMC)

        Fine Guidance Sensor #1 was used to conduct high angular resolution 
observations of some of the SMC's hottest and most luminous objects by 
conducting a comprehensive survey of nearly every spectral type in the 
upper portion of the HR diagram.  Binary or multiple star systems will be 
detected down to an unprecedented level, more than one order of magnitude 
better than possible with WFPC2.  The targets selected include a 
representative list of normal Main Sequence O-stars and their evolved 
descendents, namely supergiants, hypergiants, LBVs, and WRs, many of which 
have been previously observed by HST's spectrometers for purposes of 
cosmological calibrations.  The observations completed, and no problems 
were reported.

    1.4 Completed Three 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.

    1.5 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 Two Sets of 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 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.

    1.8 Completed FGS/1 8774 (Calibrating the Mass-Luminosity Relation at 
the End of the Main Sequence)

        Fine Guidance Sensor was used to calibrate the mass-luminosity 
relation {MLR} for stars less massive than 0.2 Msun, with special emphasis 
on objects near the stellar/brown dwarf border.  Our goals are to determine 
Mv values to 0.10 magnitude, masses to 5%, and more than double the number 
of objects with masses determined to be less than 0.20 Msun.  The proposal 
completed with no reported problems.

    1.9 Completed Four 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.

    1.10 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.

    1.11 Completed WF/PC-2 8594 (H-Deficient Condensations In Pne -- A Key 
To Discrepancies In Abundance Determinations)

        The WF/PC-2 was used to obtain deep long-slit spectra for the 
well-resolved H-deficient knots of A 30 and to search for such knots in 
A-30-6.57AR.  The data will yield the spatially resolved temperature, 
density and ionization structure of the knots in Abell 30, and, for the 
first time, accurate ORL C and O abundances for them.  The results will 
lead to a much better understanding of the physics of such knots and their 
effects on abundance determinations .  There were no reported problems.

    1.12 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.

    1.13 Completed Three Sets of STIS/CCD/MA1 8566 (High Resolution 
UV/X-Ray Spectroscopy of SMC X-1)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
perform simultaneous observations of the X-ray pulsar SMC X-1 and its B0 
companion SK160 with Chandra and ground-based optical telescopes.  The 
proposer will search for correlation between orbital phase and "bleaching'' 
of important P Cygni lines by X-ray photoionization, and will model the 
simultaneous X-ray, ultraviolet, and optical continuum emission at 
different phases of the superorbital period to measure changes in mass 
accretion rate, disk structure, and disk size.  The proposal completed with 
no reported problems.

    1.14 Completed STIS/CCD/MA2 8681 (Snapshot Survey of Variability of 
Narrow and Broad Associated Absorption Lines in Quasars)

        The Space telescope Imaging Spectrograph (CCD and MA2) was used to 
investigate the variability in the strength of absorption lines in quasar 
spectra which is definitive proof that we are observing material that is 
physically associated with the quasars.  This proposal will conduct a STIS 
snapshot survey to provide second epoch observations of 37 quasars with 
narrow associated or broad absorption lines {NALs and BALs}, previously 
observed with the FOS.  At high redshift several intrinsic NALs and about 
two thirds of BALs are known to vary, often in accord with continuum 
variability.  The amplitudes increase and the timescales decrease with 
decreasing quasar luminosity.  The proposal completed nominally.

    1.15 Completed STIS/MA1 8561 (The Ionizing Flux from Star-Forming Galaxies)

        The Space Telescope Imaging Spectrograph (MA1) was used to measure 
the meaningful upper limits on the amount of ionizing radiation from 
galaxies in the current epoch.  The proposal completed nominally.

    1.16 Completed STIS/MA1 8721 (An UV Imaging Survey of IR-Bright Star- 
Forming Galaxies)

        The Space Telescope Imaging Spectrograph (MA1) was used to carry 
out a UV {~1, 600 Angstrom} snapshot imaging survey of all the actively 
star-forming galaxies detected by ISO at Lambda>170 Mum and closer than 
cz=9000 km/s.  The sample covers a large region in the parameter's space of 
morphology, luminosity, metallicity, and star formation intensity.  There 
were no reported anomalies.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 11
Successful: 11

  Scheduled Re-acquisitions:  7
Successful:  7

    2.2 FHST Updates:
Scheduled: 25
Successful: 25

    2.3 Operations Notes:

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

        TTRs were written for three instances of required re-transmits 
during two 486 and one NSSC-1 uplinks.  For each of the 486 re-transmits 
the CCS engineering status buffer limits were adjusted per ROP DF-18A.  For 
the NSSC-1 re-transmit, ROP NS-5 was utilized to reset SI C&DH errors.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW