Status Report

Hubble Space Telescope Daily Report #2906 3 Jul 2001

By SpaceRef Editor
July 3, 2001
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HUBBLE SPACE TELESCOPE

DAILY REPORT #2906

PERIOD COVERED: 0000Z (UTC) 07/02/01 – 0000Z (UTC) 07/03/01

Daily Status Report as of 184/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Three 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.

1.2 Completed Two 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.

1.3 Completed Four 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.

1.4 Completed 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 Five 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.

1.6 Completed Three Sets of 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.

1.7 Completed WF/PC-2 8812 (Cycle 9 Internal Monitor)

The WF/PC-2 was used to obtain routine internal monitors for WFPC2
in order to monitor the health of the cameras. A variety of internal
exposures are obtained in order to provide a monitor of the integrity of
the CCD camera electronics in both bays {gain 7 and gain 15}, a test for
quantum efficiency in the CCDs, and a monitor for possible buildup of
contaminants on the CCD windows. There were no reported problems.

1.8 Completed Two 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.

1.9 Completed WF/PC-2 8720 (Masses and Multiplicity of Nearby Free-
floating Methane and L Dwarfs)

The WF/PC-2 was used to observe 50 very-low-mass objects in the
solar neighborhood with spectral types of L0 and later {including several
dwarfs with Methane absorption bands in their atmospheres}. These objects
will be observed in two filter bands with the aim to identify close
companions, measure their colors, and to obtain first epoch data of the
newly discovered binaries. The observations completed nominally.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 16

Successful: 16

Scheduled Re-acquisitions: 2

Successful: 2

2.2 FHST Updates:

Scheduled: 22

Successful: 22

2.3 Operations Notes:

The STIS instrument remains in safe mode.

The SSR EDAC error counter was cleared four times per ROP SR-1A.

Using ROP DF-18A, the engineering status buffer limits were
adjusted at 183/1202Z.

As directed by ROP IC-2, an SSA transmitter was turned on at
183/1556Z and turned off at 183/1625Z.

The ephemeris table was uplinked at 184/0048Z per ROP DF-07A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Pending NASA Headquarters approval, STIS Side 2 activation, Part 1,
is scheduled to begin at approximately 184/1600Z. Should this be
successful, the resumption of STIS science operations, on side 2, will
begin next week.

Continuation of normal science observations and calibrations.

SpaceRef staff editor.