Status Report

Hubble Space Telescope Daily Report #2925 31 Jul 2001

By SpaceRef Editor
July 31, 2001
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PERIOD COVERED: 0000Z (UTC) 07/30/01 – 0000Z (UTC) 07/31/01

Daily Status Report as of 212/0000Z


1.1 Completed Six Sets of WF/PC-2 8935 (Cycle 10 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.

1.2 Completed Four Sets of 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.

1.3 Completed Ten 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.

1.4 Completed Two 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.

1.5 Completed WF/PC-2 9227 (Observations of Astrophysically Important
Visual Binaries)

The WF/PC-2 was used to perform observations of three visual binary
stars that will ultimately yield fundamental astrophysical results, once
their orbits and masses are determined. The targets are the following: {1}
Procyon {P=41 yr}, for which our first WF/PC-2 images yielded an extremely
accurate angular separation of the bright F star and its very faint
white-dwarf companion. Combined with ground-based astrometry of the bright
star, our observation significantly revised downward the derived masses,
and brought Procyon A into excellent agreement with theoretical
evolutionary tracks for the first time. The mass of Procyon B, however,
implies a completely unexpected chemical composition for the white dwarf,
and now poses a sharp evolutionary puzzle. With the continued monitoring
proposed here, we will obtain masses to an accuracy of better than one
percent, providing a test bed for theories of Sun-like stars and white
dwarfs. {2} G 107-70, a close double white dwarf {P=19 yr} that promises to
add two accurate masses to the tiny handful of white-dwarf masses that are
directly known from dynamical measurements. {3} Mu Cas {P=21 yr}, a famous
metal-deficient G dwarf for which accurate masses will lead to the stars’
helium contents, with cosmological implications. No problems were
encountered for these observations.

1.6 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.

1.7 Completed WF/PC-2 9160 (Disks and Envelopes of Nearby Nebulous
Young Stellar Objects: A Snapshot Survey)

The WF/PC-2 was used to perform a snapshot survey of nearby
nebulous young stellar objects to study the detailed morphology of the
their disks and envelopes and probe the effect of inclination on the
infrared spectral energy distribution of disk/envelope systems. The
proposal completed as planned.

1.8 Completed WF/PC-2 9267 (Supernova Search)

The WF/PC-2 was used to search for high-redshift supernovae in
GO-observed fields, taking advantage of good first-epoch observations and
of the scheduling opportunities available because STIS is not currently
observing. No anomalous activity was reported.

1.9 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.

1.10 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.

1.11 Completed FGS/1 9097 (The Mass-Luminosity Relationship for High
Mass Stars: Resolving the `Mass Discrepancy’ with HST)

Fine Guidance Sensor #1 was used to investigate the mass-luminosity
relation for very low mass stars. This relationship is well determined for
intermediate-mass stars. The observations completed with no reported problems.

1.12 Completed Three 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

1.13 Completed FGS/1 9169 (An Interferometric Harvest of Double

Fine Guidance Sensor #1R was used to observe the white dwarf mass
and age distributions that hold clues to the star formation history of our
Galaxy and the age of the disk. No problems were reported.

1.14 Completed STIS/CCD/MA1 9053 (The Late Evolution of Low-Mass Stars:
a Deep UV Color-Magnitude Diagram of M32)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
construct a deep far-UV color-magnitude diagram of the hot stellar
population in the center of M32 {NGC221}. The previous Cycle 7 near-UV
STIS observations of the M32 core resolved 8000 stars in a single
bandpass. While these observations provided no color information, they
nonetheless showed conclusively that hot horizontal branch {HB} stars exist
in M32. Moreover, the near-UV luminosity function showed a surprising lack
of post-asymptotic giant branch {post-AGB} stars, indicating that they
evolve much more rapidly than expected from canonical theory. Obtaining
color information is the vital next step in extending this analysis. There
were no reported problems.

1.15 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.

1.16 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.

1.17 Completed STIS/MA2 8780 (Secular Changes in the Jet of M87)

The Space Telescope Imaging Spectrograph (MA2) was used to continue
the ongoing investigation of the M87 jet that had previously used the
FOC. The investigators will compare FOC and WFPC2 images to track secular
changes and motions in the jet and nucleus. The observations completed

1.18 Completed WF/PC-2 8583 (Imaging Snapshots of Asteroids)

The WF/PC-2 was used to obtain images of the fifty largest main
belt asteroids that have favorable apparitions during cycle 9. The images
will be searched for companion bodies, as well as mineralogical variegation
on the resolved main bodies. There were no reported problems.


2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 7

Successful: 7

Scheduled Re-acquisitions: 4

Successful: 4

2.2 FHST Updates:

Scheduled: 27

Successful: 26

The roll delay update at 211/081052Z failed due to tracker
#2. HSTAR 8288 was written.

2.3 Operations Notes:

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

Per ROP DF-18A, 486 engineering status buffer limits were adjusted
three times.

The ephemeris tables were uplinked at 212/0006Z, per ROP DF-07A.

The STIS MCE-2 was reset at 212/012035Z while the low voltage was
on and while outside any SAA interval. Per HSTAR 8290, this produced a
STIS status buffer message indicating that parameters did match their
expected values. The STIS flight software error counter was reset at
212/0142Z as directed by ROP NS-12. MAMA-2 will be recovered by normal
SMSM commanding at 213/1955Z.


Continuation of normal science observations and calibrations.

SpaceRef staff editor.