Status Report

Hubble Space Telescope Daily Report 2699 1 September 2000

By SpaceRef Editor
September 1, 2000
Filed under

HUBBLE SPACE TELESCOPE
 
      DAILY REPORT #2699
 
PERIOD COVERED:  0000Z (UTC) 08/31/00 – 0000Z (UTC) 09/01/00
 
Daily Status Report as of 245/0000Z
 
1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:
 
    1.1 Completed FGS 8731 (A High Angular Resolution Survey of the Most Massive Stars in the SMC)
 
        The Fine Guidance Sensors were 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.
 
    1.2 Completed STIS/CCD 7912 (STIS Parallel Archive Proposal – Nearby Galaxies – Imaging and Spectroscopy)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to make parallel observations of nearby galaxies.  This survey will be useful to study the star formation histories, chemical evolution, and distances to these galaxies.  These data will be placed immediately into the Hubble Data Archive.  The observations were completed as scheduled, and no problems were reported.
 
    1.3 Completed Seven 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.  The proposal completed with no reported problems.
 
    1.4 Completed STIS/CCD 8838 (Bias Monitor – Part 1)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns.  The proposal completed nominally.
 
    1.5 Completed Five 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.
 
    1.6 Completed WF/PC-2 8826 (Cycle 9 Supplemental Darks pt 1)
 
        The WF/PC-2 was used to perform a T dark calibration program that obtains three dark frames every day in order to provide data for monitoring and characterizing the evolution of hot pixels.  There were no reported anomalies.
 
    1.7 Completed WF/PC-2 8601 (A Snapshot Survey of Probable Nearby Galaxies)
 
        The WF/PC-2 was used to continue the very successful snapshot survey in order to use the high spatial resolution of HST to determine whether selected galaxies are nearby on the basis of resolution into stars, and the magnitudes and colors of the brightest stars.  There were no reported problems.
 
    1.8 Completed Three Sets of STIS/CCD 8808  (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation III)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal.  See HSTAR 7833.
    1.9 Completed WF/PC-2 8821 (Cycle 9 CTE Monitor)
 
        The WF/PC-2 was used to monitor CTE changes during cycle 9.  It is expected to determine CTE and zero points by comparison to ground based observations of clusters.  The observations completed nominally.
 
    1.10 Completed STIS/CCD/MA2 8197 (Detection of ^11B/^10B: Part II)
 
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to make spectrographic observations of star HD160617 to measure the boron isotope ratio (i.e., 11B/10B).  A wavelength calibration image was also taken.  The observations were completed as planned, and no anomalies were reported.
 
    1.11 Completed STIS/CCD/MA1 8603 (Secular Changes In The Temperatures And Radii Of Extreme Helium Stars)
 
        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make observations of 15 extreme helium stars (EHEs_ which, together with IUE data, will give a 20-year baseline of ultraviolet
spectrophotometry.  EHEs are luminous stellar remnants evolving rapidly to become white dwarfs.  They represent an important stage in the evolution of at least some low-mass stars, and are closely related to the R Coronae Borealis variables.  Models do not agree about their origin, nor about what fraction of normal stars pass through this phase, in which the stars have been completely stripped of their outer layers.  The models do predict that EHEs are contracting and provide rate predictions and evolutionary lifetimes.  The observations completed with no reported problems.
 
    1.12 Completed STIS/CCD/MA2 8206 (The Structure of the Accretion Flow on Pre-Main-Sequence Stars)
 
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to test an essential prediction of the magnetospheric accretion model for T Tauri stars.  Echelle spectra were be used to search for the relatively narrow high-temperature emission lines that must result from the magnetospheric accretion shock, but are not expected in the previous, alternative boundary layer model.  The observations were completed with no reported problems.
 
    1.13 Completed STIS/CCD 8631 (Bright Quasar Close Lensing Search II)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to expand the Cycle 8 second generation HST snapshot survey of bright quasars, optimized to find lenses with component image separations < 1".  The observations completed nominally.
 
2.0 FLIGHT OPERATIONS SUMMARY:
 
    2.1 Guide Star Acquisitions:
      Scheduled Acquisitions: 11
Successful: 10
 
  Scheduled Re-acquisitions: 7
Successful: 7
 
    2.2 FHST Updates:
Scheduled: 19
Successful: 17
 
    2.3 Operations Notes:
 
 
 
3.0 SIGNIFICANT FORTHCOMING EVENTS:
 
HSTAR 7831 GSA (3,2,2) failed to RGA control.  245/00:16:18z failed to RGA control due to
search radius limit exceeded on secondary FGS2, after multiple attempts through the 55
a-s radius.  Prior FM Updates showed good error vectors (a-s).  STIS 191 observation possibly affected. (proposal 08847)
 
HSTAR 7832 FM1,2 failed twice 245/05:24:29z.  Two full maneuver updates at 05:24:29 and 05:27:14 failed due to tracker 1. Map at 06:19 showed small attitude errors (8.343, 3.130, 1.988).  GSACQ(3,2,3) at 05:45:23 acquired in fine lock backup on FGS 2
 
HSTAR 7833 GSAQ (3,2,3 fails to FL backup as expected 245/05:45:23z. GSACQ(3,2,3) at    05:45:23 failed to fine lock backup on FGS 2 due to scan step limit exceeded. This acquisition used the same guide stars as used in HSTAR 7823 and was expected to fail. Reacq at 07:25 also acquired FL backup on FGS 2. Observations affected: WFPC 191 to 198 (proposal 8122), STIS 198 to 203 (proposal 8808)

SpaceRef staff editor.