HUBBLE SPACE TELESCOPE

   DAILY REPORT #2909

PERIOD COVERED:  0000Z (UTC) 07/06/01 - 0000Z (UTC) 07/09/01

Daily Status Report as of 190/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Twenty Sets of WF/PC-2 9042 (An Archive To Detect The 
Progenitors Of Massive, Core-Collapse Supernovae)

         The WF/PC-s was used to search for supernovae which have massive 
star progenitors.
The already extensive HST archive and high-resolution ground-based images 
of galaxies within ~20 Mpc enables us to resolve and quantify their 
individual bright stellar content.  As massive, evolved stars are the most 
luminous single objects in a galaxy, the progenitors of core-collapse 
supernovae should be directly detectable on pre-explosion images.  One Type 
II progenitor has been observed this year, and the investigators have 
proposed a short, companion WFPC2 proposal to confirm this candidate and 
identify a second.  The observations completed nominally.

    1.2 Completed WF/PC-2 8682 (A Snapshot Study of 0bservational Cosmology)

        The WF/PC-2 was used to examine the observational constraints on 
the cosmic star formation history that is currently among the most active 
fields in observational cosmology.  The most widely used tracer of the 
co-moving volume-averaged star formation rate {SFR} is the UV luminosity 
density, which early results found to peak at z~1- 2.  The apparent 
identification of the primary epoch of metal production and star formation 
in the Universe led to intense theoretical and observational 
interest.  Nevertheless, and remarkably for such a fundamental observation, 
little is known about the history of star formation in the Universe beyond 
its global average.  There were no reported anomalies.

    1.3 Completed Seven Sets of WF/PC-2 9124 (Mid-UV SNAPSHOT Survey of 
Nearby Irregulars: Galaxy Structure and Evolution Benchmark)

        The WF/PC-2 was used to investigate the relation between star 
formation and the global physical characteristics of galaxies to interpret 
the morphologies of distant galaxies in terms of their evolutionary 
status.  Distant galaxies are primarily observed in their rest frame 
mid-ultraviolet.  They resemble nearby late-type galaxies, but are they 
really physically similar classes of objects?  It is proposed to address 
this question through a SNAPSHOT survey in the 2 mid-UV filter F300W of 98 
nearby late-type, irregular and peculiar galaxies.  No problems were reported.

    1.4 Completed Seven 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.

    1.5 Completed Seven Sets of WF/PC-2 9162 (Local Galaxy Flows and the 
Local Mass Density)

        The WF/PC-2 was used to investigate dark matter which is the main 
constituent of the universe.  It is not know how much there is, how it is 
distributed, or its composition.  Galaxies contain dark matter that extends 
many tens of kiloparsecs from their centers, but we do not know the 
limits.  The distribution of total mass in the universe can be determined 
by modelling the orbits galaxies have followed.  The proposal completed 
with no reported problems.

    1.6 Completed Three Sets of WF/PC-2 9057 (Host Galaxies of Obscured 
QSOs Identified by 2MASS)

        The WF/PC-2 was used to perform a snapshot survey of red QSOs 
discovered in The Two Micron All Sky Survey {2MASS} to investigate the 
detailed properties of their host galaxies.  This large, possibly dominant, 
population of QSOs in the local universe has been previously overlooked 
because reddening by {intrinsic} obscuration along our line of sight causes 
their colors to be too red for identification by traditional "UV- excess" 
techniques.  Their near-IR colors are similar to PG- type {UV-excess} QSOs, 
but it is far from certain whether they are indeed from the same parent 
population or represent a completely new class of QSO.  There were no 
reported problems.

    1.7 Completed WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)

        The WF/PC-2 was used to perform a snapshot survey of local galaxies 
at UV wavelengths with the F300W filter.  The aim of the project is to 
build a reference UV Atlas of normal galaxies, whose optical images are 
well known, with the highest possible degree of information, covering all 
the morphological types and luminosity classes.  The proposal completed 
normally.

    1.8 Completed Five Sets of 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.

    1.9 Completed FGS/1 9168 (The Distances to AM CVn Stars)

        Fine Guidance Sensor (FGS) #1 was used to determine the parallaxes 
and proper motions of the five brightest of the seven known AM CVn systems 
using the HST FGSs.  AM CVn systems are binaries where mass is transferred 
from a completely hydrogen-deficient, degenerate mass donor to a white 
dwarf primary through a helium accretion disk.  A better understanding of 
these systems is crucial for a number of reasons: (1) to study the late 
stages of binary evolution, (2) to study the effect of chemical composition 
on the physics of accretion discs, (3) to estimate their contribution to 
the Supernovae Ia rate, and (4) to estimate their contribution to the 
gravitational radiation background.  All observations completed with no 
reported problems.

    1.10 Completed Two 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.

    1.11 Completed WF/PC-2 9087 (Black Hole X-ray Transients and X-ray 
Binaries in M31)

        The WF/PC-2 was used to search for M31 for x-ray transients which 
had previously been seen as part of the Chandra Guaranteed Time 
Observations {GTO} program.  The x-ray properties of these transient 
sources {spectra, variability} allow us to determine whether the accreting 
object is a black hole or a neutron star.  It is proposed to determine the 
nature of the mass-losing star.  Massive stars will show little {<2 mag} 
change in their UV luminosities during outbursts, while low-mass stars will 
show large {>5 mag} changes in their UV luminosities.  By determining the 
nature of the primary {accreting} and secondary stars in these x-ray 
transients, we will have the first dataset that will allow the evolution of 
black hole and neutron star binaries to be studied in an external 
galaxy.  The proposal completed nominally.

    1.12 Completed FGS/1R 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.

    1.13 Completed WF/PC-2 9050 (Outflow Collimation in Bipolar Symbiotic 
Nebulae)

        The WF/PC-2 was used to observe flow collimation in evolved stars 
that is neither expected nor understood.  Classical theories of stellar 
evolution do not predict and cannot explain this bipolarity.  More exotic 
concepts {binary interactions, spun-up atmospheres, poloidal or toroidal 
magnetized winds} have been proposed, but observations are yet to verify or 
falsify any of their predictions.  This proposal will probe the 
near-nuclear morphology and kinematics of four bright, low-extinction 
targets whose large-scale structure is highly bipolar.  The goal is to 
provide a detailed description of the circumnuclear outflows, to uncover 
the physical structure and nature of the collimator, and to evaluate the 
speculative collimation mechanisms.  The bright nucleus has hampered 
efforts to explore the nebular collimators that lie close to the star, so 
we'll use STIS to disperse the nuclear light and, thus, to avoid its 
glare.  A secondary goal is to obtain second-epoch WFPC2 images of all 
targets.  There were no reported problems.

    1.14 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.

    1.15 Completed WF/PC-2 9043 (Cepheid Distances to Early-type Galaxies)

        The WF/PC-2 was used to continue observations in the HST Key 
Project on the Extragalactic Distance Scale and the HST project on the 
"Calibration of Nearby Type Ia Supernovae'' that have greatly improved our 
knowledge of the Hubble Constant by providing a solid zero point for the 
Tully- Fisher {TF} relation and Type Ia Supernovae {SNIa}.  However, severe 
inconsistencies remain for distance estimators to early-type galaxies such 
as surface brightness fluctuations {SBF}, the planetary nebula luminosity 
function {PNLF}, the fundamental plane {FP}, and the globular cluster 
luminosity function {GCLF}.  As a result, the distance to the Virgo cluster 
core remains uncertain by as much as 20 determination is directly affected 
by a lingering 0.1 mag {5 uncertainty in the photometric calibration of the 
WFPC2.  Resolving these issues is essential not only to firm up the 
extragalactic distance scale, but also to understand the mass and velocity 
structure of the local universe. SBF in particular is emerging as the 
method of choice for mapping local velocity fields to 10, 000 kms because 
it offers an order of magnitude less Malmquist bias than TF, and SNIa are 
too rare to study large scale flows effectively.  This project will tighten 
the photometric calibration of the WFPC2, and provide a solid Cepheid 
calibration for SBF and PNLF.  The observations completed nominally.

    1.16 Completed WF/PC-2 8820 (Wavelength Stability of Narrow Band and 
Linear Ramp Filters)

        The WF/PC-2 was used to verify the mapping of wavelength as a 
function of CCD position on linear ramp filters and to check for changes in 
central wavelengths of the narrow band filters.  The proposal completed 
nominally.

    1.17 Completed WF/PC-2 9157 (Fundamental Properties Of L-Type Dwarfs In 
Binaries)

        The WF/PC-2 was used to characterize the physical properties of 
eight L-dwarfs in four binary systems.  The goal is to obtain astrometric, 
photometric and spectroscopic measurements of each component that will 
yield basic information on atmospheric and dynamical properties.  The 
proposal completed nominally.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 47
Successful: 47

  Scheduled Re-acquisitions:  3
Successful:  3

    2.2 FHST Updates:
Scheduled: 95
Successful: 93

        As described in HSTAR 8258, the full maneuver updates scheduled for 
188/044813Z and at 188/145058Z failed due to tracker #1.  The following 
acquisition was successful.

    2.3 Operations Notes:

        The Space Telescope Imaging Spectrograph (STIS) was commanded to 
Side 2 MECH operate mode at 187/145603Z.  STIS remained in that mode for 
approximately two-and-one-half hours while operations, SI SEs, flight 
software, and STScI personnel verified nominal operating 
conditions.   After that time, STIS was commanded to safe mode.  The 
instrument will remain in that state until Side 2 science operations will 
commence at 191/1320Z.

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

        The 486 engineering status buffer limits were adjusted seven times 
per ROP DF-18A.

        Per ROP NS-3, the NSSC-1 status buffer was dumped and reset at 
187/1416Z.

        The SSR playback pointer was set at 188/1043Z as directed by ROP SR-3.

        A TTR was written when there was a required re-transmit at 
190/0721Z during a 486 uplink.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW