Status Report

Hubble Space Telescope Daily Report #2798 01/31/01

By SpaceRef Editor
January 31, 2001
Filed under ,

PERIOD COVERED:  0000Z (UTC) 01/30/01 – 0000Z (UTC) 01/31/01
Daily Status Report as of 031/0000Z
    1.1 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.
    1.2 Completed Two 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.
    1.3 Completed STIS/CCD 8881 (An Unbiased Survey of X-Ray and Optical Emission From Extended Radio Jets in AGN)
        The Space Telescope Imaging Spectrograph (CCD) was used to an X-ray bright jet in the distant quasar PKS 0723+679 that shows that X-rays can be energetically dominant in relativistic jets.  The observations completed nominally.
    1.4 Completed Three 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.
    1.5 Completed Two Sets of STIS/CCD 8837 (CCD Dark Monitor-Part 1)
        The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks.  The proposal completed with no reported problems.
    1.6 Completed Four 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.
    1.7 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.
    1.8 Completed STIS/CCD/MA1 8157 (Molecular Hydrogen in the
Circumstellar Environments of T Tauri Stars)
        The Space Telescope Imaging Telescope (CCD and MA1) was used to probe the gaseous environments of low mass pre-main sequence stars by studying the H_2 UV Lyman bands.  Fluorescent H_2 Lyman band emission has been detected, pumped by H I Lyman Alpha and Si IV, in 8 classical T Tauri stars but not in 3 naked T Tauri stars. The observations will provide insights into the spatial distribution of gas near classical T Tauri stars.  The proposal completed with no reported problems.
    1.9 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.
    1.10 Completed 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.
    2.1 Guide Star Acquisitions:
      Scheduled Acquisitions:  5
Successful:  5
        The acquisition at 031/074548Z defaulted to fine lock back-up on FGS-1 when the scan step limit was exceeded on FGS-3.  A subsequent map showed relatively small errors.  The following acquisition was
successful.  HSTAR 8067 was written.  STIS proposal 8633, occurring during the period of the next report, may have been affected.
  Scheduled Re-acquisitions: 11
Successful: 11
    2.2 FHST Updates:
Scheduled: 12
Successful: 12
    2.3 Operations Notes:
        The SSR EDAC error counter was cleared twice per ROP SR-1A.
        Using ROP SR-3, the SSR science playback pointer was set at 030/1727Z.
        Continuation of normal science observations and calibrations.

SpaceRef staff editor.