Status Report

Hubble Space Telescope Daily Report #2909 9 Jul 2001

By SpaceRef Editor
July 9, 2001
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PERIOD COVERED: 0000Z (UTC) 07/06/01 – 0000Z (UTC) 07/09/01

Daily Status Report as of 190/0000Z


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

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

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

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

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

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.


2.1 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

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.


Continuation of normal science observations and calibrations.

SpaceRef staff editor.