Status Report

Hubble Space Telescope Daily Report #2719 10/02/00

By SpaceRef Editor
October 2, 2000
Filed under

HUBBLE SPACE TELESCOPE
 
  DAILY REPORT #2719
 
PERIOD COVERED:  0000Z (UTC) 09/29/00 – 0000Z (UTC) 10/02/00
 
Daily Status Report as of 276/0000Z
 
1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:
 
    1.1 Completed Six Sets of 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.
 
    1.2 Completed STIS/CCD/MA2 8161 (Boron in the Magellanic Clouds: A Novel Test of Light Element Formation)
 
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to make observations of the star AV304 which is located in the Large Magellanic Cloud is order to study light element formation in that region.  Observations of boron abundances in the Magellanic Clouds will provide a novel test of the assertion that boron is produced primarily through spallation reactions between cosmic rays and ambient interstellar nuclei.  A wavelength calibration image was also taken.  The observations were completed as planned, and no anomalies were reported.
 
    1.3 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.
 
    1.4 Completed Eight 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.
 
    1.5 Completed Two Sets of WF/PC-2 8544 (POMS Test Proposal: WFII Backup Parallel Archive Proposal II)
 
        The WF/PC-2 was used to execute a POMS test proposal that was designed to simulate scientific plans.  No problems were encountered.
 
    1.6 Completed Three Sets of 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.
 
    1.7 Completed WF/PC-2 8563 (Determining the Duplicity of Nearby T Dwarfs {Methane Brown Dwarfs})
 
        The WF/PC-2 was used to investigate the binary fraction of T-type dwarfs {methane brown dwarfs} which is crucial to accurate determinations of the T-dwarf space density and mass function, especially since equal- magnitude binaries can introduce significant biases in photometric distance estimates.  The proposal completed nominally.
 
    1.8 Completed Thirteen Sets of STIS/CCD 8562 (Probing the Large Scale Structure: Cosmic Shear Observations) HST
 
        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 losses of lock described in 2.1 and HSTAR 7879 occurred during the twelfth iteration of this proposal, affected some or all of the observations in that iteration.  Otherwise, the proposal completed nominally.
 
    1.9 Completed Six 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.
 
    1.10 Completed Two Sets of WF/PC-2 8811 (Cycle 9 Standard Darks)
 
        The WF/PC-2 was used to obtain dark frames every week in order to provide data for the ongoing calibration of the CCD dark current rate, and to monitor and characterize the evolution of hot pixels.  Over an extended period these data will also provide a monitor of radiation damage to the CCDs.  The proposal completed with no reported problems.
 
    1.11 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.
 
    1.12 Completed WF/PC-2 8597 (The Fueling of Active Nuclei: Why Are Active Galaxies Active?)
 
        The WF/PC-2 was used to investigate the accretion onto massive black holes that are believed to be the energy source for AGN.  However, evidence for black holes in quiescent galaxies has also been reported.  Why are these galaxies inactive?  One possibility is that active galaxies are better at providing fuel to the nuclear region than quiescent
galaxies.  Other possible fueling mechanisms such as “bars-within-bars” or nuclear spirals cannot be investigated from the ground because they are relatively small features in the ISM.  The observations were completed as planned.
 
    1.13 Completed Two Sets of STIS/CCD/MA1 8629 (The Search for “True” Starburst Dust and the Importance of Metallicity on Properties of O & B Stars)
 
        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to observe starburst {SB} galaxies, at low and high redshift, to see whether there is any dependence between the nature of the SB dust extinction and the intrinsic physical parameters of OB stars versus
metallicity.  Typically SBs, unlike our Galaxy, exhibit extinction laws with no 2200Angstrom peak.  There is little information on the effects of dense star-formation on dust extinction properties.  Specifically, no UV-visual extinction studies exist for the dense star-forming regions of 30 Dor {LMC} and NGC 346 {SMC}, which represent prime laboratories for studying these effects.  There were no reported problems with these observations.
 
    1.14 Completed Two Sets of 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.
 
    1.15 Completed STIS/CCD/MA2 8569 (A New Survey for Low-Redshift Damped Lyman-Alpha Lines in QSO MgII Systems)
 
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to support studies which have shown that most of the observable neutral gas mass in the Universe resides in QSO damped LyAlpha {DLA} systems.  However, at low redshift , DLA can only be found by searching in the UV with HST.  By boot-strapping from the MgII statistics, we will be able to further improve the determination of the low- redshift statistical properties of DLA {their incidence and cosmological mass density} and open up new opportunities for studies at low redshift.  The observations completed nominally.
 
    1.16 Completed STIS/CCD/MA2 7316 (Saturn’s Satellites: Alteration of the Surface by Ion Irradiation on Enceladus and Tethys)
 
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to make observations of Saturn’s moon Enceladus.  Saturn’s medium-sized icy satellites display a diverse range of surface alteration caused by one or more external processes.  A wavelength calibration image was also taken.  The observations were completed as planned, and no anomalies were noted.
 
    1.17 Completed Two Sets of 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
 
    1.18 Completed STIS/CCD 8846 (Imaging Flats C9)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to investigate flat-field stability over a monthly period.  The proposal completed nominally.
 
    1.19 Completed WF/PC-2/STIS/CCD 8568 (A Seminal Spectroscopic and Imagery Investigation of the Brightest Wolf-Rayet Shell Nebula: NGC 6888)
 
        The WF/PC-2 (for imagery) and the Space Telescope Imaging Spectrograph (CCD for UV-optical-NIR spectroscopy of several regions in the brightest Wolf-Rayet Shell) were used to observe Nebula {WRSN}, NGC 6888.  The physical conditions in the wind-driven and/or stellar ejected plasma {temperature, density, ionization, and composition} of WRSN, which are dominated by strong stellar winds from hot massive stars in an advanced state of evolution, often involve emission from both shock-ionized and photoionized gas in close proximity.  These new observations will comprise the first combined spectroscopy and imagery of a WRSN at a resolution sufficient to separate and individually analyze these two emission regions.  The proposal completed nominally with no reported problems.
 
    1.20 Completed WF/PC-2 8085 (Imaging of High Redshift Starburst Galaxies in the Light of Lyman-Alpha)
 
        The WF/PC-2 was used to make Lyman-Alpha wavelength observations of the high redshifted starbursting galaxy Q2348-011.  The observations were completed as planned, and no anomalies were reported.
 
    1.21 Completed STIS/CCD 8845 (Spectroscopic Flats C9)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to obtain CCD flats in the spectroscopic mode.  The observations completed with no reported problems.
 
    1.22 Completed STIS/CCD 8176 (Confirmation and Characterization of Brown Dwarfs and Giant Planets from NICMOS 7226/7227)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to make confirmation and characterization observations of object BRI0021-21.  This is a continuation of NICMOS 7226/7227 using the STIS.  A systematic search for giant planet and brown dwarf companions to stars in the solar neighborhood was the cornerstone of the NICMOS IDT’s Environments of Nearby Stars {EONS} program.  The observations were completed as planned, and no anomalies were reported.
 
    1.23 Completed WF/PC-2/STIS/MA2 8120 (Determination of Circumstellar Cloud Mass Loss Rates with STIS Spectra)
 
        Both the WF/PC-2 and the Space Telescope Imaging Spectrograph (MA2) were used to make observations of the star cluster NGC-1976 to determine its circumstellar cloud mass loss rate.  Only the HST and STIS have the right combination of spatial and spectral resolution to adequately reject the contaminating light from the Orion Nebula itself and allow clear determination of the emission coming from the young stellar object.  The observations were complete as planned, and no anomalies were reported.
 
    1.24 Completed WF/PC-2 8602 (A Snapshot Survey of the Sites of Recent, Nearby Supernovae)
 
        The WF/PC-2 was used to conduct a snapshot survey in V and I of the sites of the nearby SNe, which have precisely known positions, to obtain high-resolution information on their local environment.  The proposal completed with no reported problems.
 
    1.25 Completed STIS/CCD/MA1/MA2 8029 (Intrinsic Absorption Lines in Seyfert 1 Galaxies)
 
        The Space Telescope Imaging Spectrograph (CCD, MA1, and MA2) was used to study the origin of the intrinsic absorption lines in the UV spectra of Seyfert 1 galaxies and their connection to the emission-line and X-ray absorption regions.  The observations completed nominally.
 
    1.26 Completed STIS/CCD/MA1/MA2 8857 (MAMA Sensitivity and Focus Monitor C9)
 
        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used to monitor the sensitivity of each MAMA grating mode to detect any change due to contamination or other causes.  There were no problems.
 
  1.27 Completed STIS/CCD/MA2 8711 (C/O Abundance Ratios Across WCL Planetary Nebulae With Strong PAH And Crystalline Silicate Emission)
 
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to measure the required high angular resolution across compact nebulae for the crucial abundance-diagnostic lines of C ii 2326 Angstrom and O ii 2470 Angstrom.  ISO has discovered cool O-rich crystalline silicate and water- ice emission in the far-IR spectra of several planetary nebulae {PNe} which show very strong hot PAH {polycyclic aromatic hydrocarbon, carbon-rich} emission bands in their near- and mid-IR spectra.  All of these PNe are young and compact and of low-ionization, and have cool H-deficient Wolf- Rayet central stars.  The correlation with carbon-rich WCL Wolf-Rayet central stars suggests that the phenomenon is associated with a recent transition from an O-rich to a C-rich phase by the evolving objects, following the exposure of 3rd dredge-up enriched material.  For these nebulae, the gas-phase C/O ratios {two of the nebulae have the largest C/O ratios known} are strongly correlated with the PAH feature strength.  The unexpected discovery of cool oxygen-rich particles around them suggests that strong C/O abundance gradients may be present in the nebulae.  The observations completed nominally.
 
    1.28 Completed WF/PC-2 8183 (Morphology of the Most Massive Galaxies in the Early Universe)
 
        The WF/PC-2 was used to make observations of the massive radio galaxy MRC2048-27 in order to study its morphology.  High redshift radio galaxies are fundamentally important probes of galaxy and cluster formation.  The observations were completed as scheduled, and no anomalies were reported.
 
    1.29 Completed WF/PC-2 8634 (Atmospheric Variability on Uranus and Neptune)
 
        The WF/PC-2 was used to obtain snapshot observations of Uranus and Neptune to monitor changes in their atmospheres on time scales of months to years.  Uranus is rapidly approaching equinox in 2007, with another 4 degrees of latitude in the Northern Hemisphere becoming visible every year.  Recent HST images during this unique epoch have revealed: {i} strongly wavelength-dependent latitudinal structure, {ii} the presence of numerous visible-wavelength cloud features in the northern hemisphere, and, {iii} in the near-IR, discrete features northward of 25degrees N that have the highest contrast ever seen for a Uranian cloud.  Long-term ground- based observations show seasonal brightness changes whose origins are not well understood.  Recent IR images of Neptune obtained using adaptive optics on the Keck Telescope indicate that a new "Bright Companion" type of feature has recently appeared in the southern hemisphere.  Snapshot observations of these two dynamic planets can supply context in which to discern the nature of long-term changes in their latitudinal atmospheric bands and to track the appearance, movement, and disappearance of discrete albedo features.  There were no reported problems.
 
    1.30 Completed Two Sets of STIS/CCD 8840 (Read Noise Monitor)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to measure the read noise of all the amplifiers on the STIS CCD using pairs of bias frames.  Full frame and binned observations are made in both Gain 1 and Gain 4, with binning factors of 1 x 1, 1 x 2, 2 x 1 and 2 x 2.  All exposures are internals.  The observations completed with no reported problems.
 
    1.31 Completed WF/PC-2 8095 (Accurate Proper Motions of Galactic Halo Populations)
 
        The WF/PC-2 was used to make observations of the galaxy RETICULUM in order to study the proper motion of its galactic halo population, which include globular clusters and dwarf galaxies.  The proper motions of these populations will be determined to unprecedented accuracy, approximately an order of magnitude better than has been previously possible.  The observations were executed as scheduled, and no anomalies were noted.
 
    1.32 Completed WF/PC-2 8090 (POMS Test Proposal: WF-II Parallel Archive Proposal Continuation)
 
        The WF/PC-2 was used in the parallel mode to make some low galactic latitude archive observations.  The program will be used to take parallel images of random areas of the sky.  The observations were executed as scheduled, and no anomalies were noted.
 
    1.33 Completed STIS/CCD 8870 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation IV)
 
        The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal.  The observations completed with no anomalous activity.
 
    1.34 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 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 losses of lock described in 2.1 and HSTAR 7879 occurred during this proposal, affected some or all of the observations.  Otherwise, the observation completed as planned.
 
    1.35 Completed FGS 8618 (Parallaxes of Magnetic CVs)
 
        The FGSs were used to gather data for the calculation of trigonometric parallaxes of cataclysmic variable {CVs} which are needed to obtain reliable information on luminosities, accretion rates, and on radii and masses of the stellar components.  They are also needed to derive the space density, an important ingredient for theories of CV evolution.  The observations completed with no reported problems.
 
2.0 FLIGHT OPERATIONS SUMMARY:
 
    2.1 Guide Star Acquisitions:
      Scheduled Acquisitions: 25
Successful: 25
 
        There were losses of lock, following a successful acquisition, at 275/200414Z, at 275/200725Z, at 275/201421Z, at 275/202752Z and at 275/203806Z there were losses of lock.  HSTAR 7879 was written.  The proposals described in 1.8 and 1.34 were affected.
  Scheduled Re-acquisitions: 21
Successful: 21
 
    2.2 FHST Updates:
Scheduled: 53
Successful: 52
 
        Per HSTAR 7878, the roll delay update scheduled for 274/090355Z failed.  However, the following two full maneuver updates were successful.
 
    2.3 Operations Notes:
 
        Using ROP SR-1A, the SSR EDAC error counter was cleared ten times.
 
        The engineering status buffer limits were adjusted fives times per ROP DF-18A.
 
        According to HSTAR 7875, at 273/155040Z during an SAA transit, there was a possible FGS-3 "bit flip".  QF3SRLEX flagged out-of-limits followed shortly by QF3STOPF, QSRCHEXC, and QSTOP.  At the time the FGSs were not guiding and the HST was in gyro hold.
 
        SI C&DH errors were reset at 275/1707Z per ROP NS-5.
 
        A TTS was written when a command re-transmit occurred during a NSSC-1 load uplink at 275/165629Z.
 
        Although Blade A was OPEN and Blade B was CLOSED for the entire duration of the event. A WF/PC-2 error message (UERRMSG1) was produced at 276/085919Z and four additional nearby times.  HSTAR 7880 was
written.  This is the same shuttle "anomaly" that was documented in HSTAR 7830.
 
3.0 SIGNIFICANT FORTHCOMING EVENTS:
 
        Continuation of normal science observations and calibrations.

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