Hubble Space Telescope Daily Report #2938 – 17 Aug 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2938

PERIOD COVERED: 0000Z (UTC) 08/16/01 – 0000Z (UTC) 08/17/01

Daily Status Report as of 229/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Eight 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. The
observations completed with no anomalous activity.

1.2 Completed Two Sets of WF/PC-2 8867 (Gamma-Ray Bursts: Discovering
The Progenitors And Understanding The Explosion – Visits A0-R0)

The WF/PC-2 was used to observe a gamma-ray burster,
GR970828. Gamma-ray burst astronomy, one of the most active and exciting
frontiers in astrophysics, is now entering a critical stage — with
dramatic leaps in understanding of these events, as well as new
discoveries. Improvements in triggering and positioning accuracy provided
by the SAX and HETE-2 gamma-ray satellites will allow entirely new classes
of events to be studied. Given the recent progress in this field, the
proposers are now in a position to design precision, broadband measurements
that can provide quantitative information on the as-yet unknown energy
sources, the explosion geometry, and the surrounding medium. In
particular, the growing evidence of an intimate connection between SNe and
GRBs can be definitively tested. The proposal completed with no reported
problems.

1.3 Completed Four 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.

1.4 Completed STIS/CCD 8864 (CCD Dark Monitor-Part 2)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks for the CCD. The proposal completed nominally.

1.5 Completed STIS/CCD 8865 (Bias Monitor-Part 2)

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 with no anomalous activity.

1.6 Completed Seven Sets of STIS/CCD 8907 (Spectroscopic Flats C10)

The Space Telescope Imaging Spectrograph (CCD) was used to obtain
CCD flats in the spectroscopic mode. There were no reported problems.

1.7 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.

1.8 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.

1.9 Completed Three Sets of WF/PC-2 8941 (Cycle 10 UV Earthflats)

The WF/PC-2 was used to monitor flat field stability by obtaining
sequences of earth streak flats to improve the quality of pipeline flat
fields for the WFPC2 UV filter set. The proposal had no problems.

1.10 Completed Two Sets of STIS/CCD 9285 (POMS Test Proposal: STIS
Non-scripted Parallel Proposal Continuation III)

The Space Telescope Imaging Spectrograph (CCD) was used to make low
galactic latitude, non-scripted parallel observations as part of a POMS
test proposal. The observations were completed as planned, and no
anomalies were reported.

1.11 Completed 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.

1.12 Completed GFS/1 8897 (Long Term Monitoring of FGS1R in Position Mode)

Fine Guidance Sensor #1R was used to monitor its long term
evolution, presumably due to disorption of water from the instrument’s
graphite epoxy composits. This manifests principally as a change in the
plate scale and secondarily as a change in the distortions. These effects
are well modeled by adjustments to the rhoA and kA parameters which are
used to transform the star selector servo angles into FGS {x, y} detector
space coordinates. By observing the relative positions of stars in a
standard cluster at a fixed telescope pointing and orientation, the
evolution of rhoA and kA can be monitored and calibrated to preserve the
astrometric integrity of the FGS. There were no reported problems.

1.13 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.

1.14 Completed STIC/CCD/MA2 9051 (Identifying Damped Lyman-alpha
Galaxies at z~1)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
look for samped Lyman-alpha absorption systems that contain the bulk of the
neutral gas in the Universe in the redshift range z = 0.5 – 5 ,yet the
nature of the galaxies responsible for the absorption is not well
understood. Only recently have observers found more than a handful of
damped absorbers at redshifts z < 1.5. Using the FIRST Bright Quasar Survey {FBQS}, with over a 1000 quasars, the proposers have undertaken a survey to build a complete picture of he nature of the galaxies responsible for damped Lyman-alpha absorption systems at z~1 and to double the sample size at this redshift. No problems were encountered.

1.15 Completed STIS/CCD 9176 (LMC Eclipsing Binaries with Cepheid
Components: The Key to the Extragalactic Distance Scale)

The Space Telescope Imaging Spectrograph (CCD) was used to
determine the distance to the LMC and to observe the Cepheid P-L that law
form the backbone of the Cosmic Distance Scale and the determination of
H_degrees. Unfortunately, in spite of concerted efforts of many
investigators, the zero point of the Cepheid P-L law and the LMC distance
remain controversial and uncertain to ~10-15, using eclipsing binaries
{EBs} as “standard candles” to include two recently discovered LMC
eclipsing binaries {EBs} with Cepheid components. These observations of
these extraordinary systems hold the key to determining simultaneously the
Cepheid P-L zero point and the LMC distance, and to provide a direct test
of the Baade-Wesselink parallax method. There were no reported problems.

1.16 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.

1.17 Completed WF/PC-2 9249 (POMS Test Proposal: WFII Backup Parallel
Archive Proposal II)

The WF/PC-2 was used to execute a POMS test proposal designed to
simulate scientific plans. The proposal completed with no reported problems.

1.18 Completed STIS/CCD 9110 (A Search for Kuiper Belt Object Satellites)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate whether the large number of collisions thought to have taken
place in the primordial Kuiper belt suggest that many Kuiper belt objects
{KBOs} could have suffered binary-forming collisions similar to that which
formed the Pluto — Charon binary. Detection of such KBO satellites would
allow measurement of KBO masses, would help to understand the past
collisional environment of the Kuiper belt, and would give a context to the
otherwise unique-seeming formation of the Pluto — Charon binary. The
proposal completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 10

Successful: 10

Scheduled Re-acquisitions: 5

Successful: 5

2.2 FHST Updates:

Scheduled: 28

Successful: 28

2.3 Operations Notes:

Using ROP SR-1A, the SSR EDAC error counter was cleared twice per
ROP SR-1A.

A TTR was generated when HST Internal Ground Configuration Data was
lost from 228/211216Z until 228/211528Z. This data is unrecoverable.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.