Status Report

Hubble Space Telescope Daily Report #2913 13 Jul 2001

By SpaceRef Editor
July 13, 2001
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PERIOD COVERED: 0000Z (UTC) 07/12/01 – 0000Z (UTC) 07/13/01

Daily Status Report as of 194/0000Z


1.1 Completed Two Sets of WF/PC-2 8825 (Decontaminations and Associated
Observations 4/4)

The WF/PC-2 was used to perform the monthly decontaminations
(decons). Also included are instrument monitors tied to decons:
photometric stability check, focus monitor, pre- and post-decon internals
{bias, intflats, kspots, & darks}, UV throughput check, VISFLAT sweep, and
internal UV flat check. As described in yesterday’s report and HSTAR 8268,
an acquisition for the first iteration of this proposal failed, affecting
six observations. Otherwise, the proposal completed with no further
reported problems.

1.2 Completed Two Sets of STIS/MA1/MA2 9261 (Mini-OV MAMA Turn-on)

The Space Telescope Imaging Spectrograph (MA1/MA2) was used to turn
on MAMA high voltages and take darks several times per day for a period of
two days, with the last dark occurring as close as possible to the end of a
set of SAA-free orbits. The proposal completed with no reported problems.

1.3 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.

1.4 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.

1.5 Completed FGS/1 8731 (A High Angular Resolution Survey of the Most
Massive Stars in the SMC)

Fine Guidance Sensor #1 was used to conduct high angular resolution
observations of some of the SMC’s hottest and most luminous objects by
conducting a comprehensive survey of nearly every spectral type in the
upper portion of the HR diagram. Binary or multiple star systems will be
detected down to an unprecedented level, more than one order of magnitude
better than possible with WFPC2. The targets selected include a
representative list of normal Main Sequence O-stars and their evolved
descendents, namely supergiants, hypergiants, LBVs, and WRs, many of which
have been previously observed by HST’s spectrometers for purposes of
cosmological calibrations. The observations completed, and no problems
were reported.

1.6 Completed WF/PC-2 8581 (A Search For Low-Mass Companions To
Ultracool Dwarfs)

The WF/PC-2 was used to search for very low-mass {VLM} companions
to a complete sample of 120 late-M and L dwarfs, drawn mainly from the
2MASS and SDSS surveys. The primary goal is to determine the multiplicity
of M < 0.1 M_odot dwarfs. In particular, we aim to identify binary systems suitable for long-term astrometric monitoring and mass measurement, and systems with cool, sub-1000K companions. The proposal completed with no reported problems.

1.7 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.

1.8 Completed Five Sets of WF/PC-2 9235 (The Asymmetric Atmosphere of

The WF/PC-2 was used to image Uranus as the planet plunges toward
equinox in 2007. Recent HST images during this unique epoch have revealed:
{i} strongly wavelength-dependent latitudinal structure, {ii} the presence
of numerous visible-wavelength cloud features in the northern hemisphere,
{iii} zonal winds which may deviate from the smooth profile implied by the
Voyager observations in 1986, and, {iv} in the near-IR, discrete features
northward of +25 degs that have the highest contrast ever seen for a
Uranian. Specific scientific issues that were addressed with these
observations are: whether the northern features are indicative of intrinsic
change or result simply from a change of viewing angle; the shape and
stability of the zonal wind profile; and the source of the as-yet
unexplained variations of the atmospheric reflectivity. No problems were

1.9 Completed Two Sets of WF/PC-2 8599 (A Census of Nuclear Star
Clusters in Late-Type Spiral Galaxies)

The WF/PC-2 was used to conduct an I-band snapshot survey of a
well-defined sample of nearby, face-on spiral galaxies of type Scd or
later. The proposal completed nominally.

1.10 Completed STIS/CCD 8841 (Hot Pixel Annealing C9)

The Space Telescope Imaging Spectrograph (CCD) was used to improve
the effectiveness of the CCD hot pixel annealing process. This is assessed
by measuring the dark current behavior before and after annealing and by
searching for any window contamination effects. In addition CTE
performance is examined by looking for traps in a low signal level
flat. The observations completed with no reported problems.

1.11 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

1.12 Completed WF/PC-2 8598 (Snapshot Survey of Extended OIIl Lambda
5007Angstrom Emission in Seyfert Galaxies)

The WF/PC-2 was used for a snapshot survey of narrow band OIII
Lambda 5007Angstrom images for a well defined sample of 88 Seyfert galaxies
{29 Seyfert 1s and 59 Seyfert 2s}, 18 of which already have data in the
archive, selected from a mostly isotropic property, the 60Mum flux. These
data will be used: 1} to determine the origin of the misalignment between
the accretion disk axis and the host galaxy plane axis, which can be due to
mergers with other galaxies, or by the self induced radiation warping; 2}
to compare the size and shape of the Narrow Line Regions (NLR) of Seyfert
1s and Seyfert 2s, and to study the frequency of conically shaped NLR in
Seyfert galaxies, which are usually unresolved from ground-based
observations; and 3} estimate the importance of shocks to the ionization of
the NLR. The observations completed with no reported problems.

1.13 Completed Three Sets of WF/PC-2 8701 (Multiplicity among Very-Low
Mass Stars and Brown Dwarfs in Alpha Persei and the Pleiades)

The WF/PC-2 was used to observe open clusters which provide
excellent hunting grounds for brown dwarf {BD} searches. The AlphaPer and
Pleiades clusters are young, nearby and have low extinction. They are
considered to be the best-suited places to study the Substellar Mass. A
dozen of cool faint AlphaPer and Pleiades members have been confirmed as
“bona-fide” BDs with the lithium test. By comparison with those, about
60 very good cluster BD candidates are currently known. The Pleiades SMF
obtained using the most recent deep large CCD surveys indicates that BDs
are quite numerous but do not make a significant contribution to the total
cluster mass. The observations completed with no reported problems.

1.14 Completed WF/PC-2 9259 (Astrometry and Photometry of the binary
TNO 1998 WW31)

The WF/PC-2 was used to confirm the discovery that the Trans
Neptunian Object {TNO} 1998 WW31 has a satellite. Observations of this
object would be of immense public interest. Combining images taken at
separate epochs would afford an opportunity to derive the orbit and
physical parameters of this system. As described in 2.1 and HSTAR 8270,
the acquisition for this proposal defaulted to fine lock backup on one FGS
only, possibly affecting six observations. Otherwise, the observations
completed nominally.

1.15 Completed STIS/MA1/MA2 9264 (Side 2: MSM Positioning of STIS MAMA

The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to
measure the MSM positions for different STIS modes which are slightly
different when the STIS is run through side 2 than when it is run from side
1. No anomalous activity was reported.

1.16 Completed WF/PC-2 8597 (The Fueling of Active Nuclei: Why are
Active Galaxies Active?)

The WF/PC-2 was used to investigate the accretion onto massive
black holes that are believed to be the energy source for AGN. However,
evidence for black holes in quiescent galaxies has also been reported. Why
are these galaxies inactive? One possibility is that active galaxies are
better at providing fuel to the nuclear region than quiescent
galaxies. Other possible fueling mechanisms such as “bars-within-bars”
or nuclear spirals cannot be investigated from the ground because they are
relatively small features in the ISM. The observations were completed as


2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 18

Successful: 18

The acquisition at 193/210515Z defaulted to fine lock backup on
FGS-3 only. HSTAR 8270 was written. The proposal detailed in 1.4 may have
been affected.

Scheduled Re-acquisitions: 2

Successful: 2

2.2 FHST Updates:

Scheduled: 31

Successful: 31

2.3 Operations Notes:

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

The 486 engineering status buffer limits were adjusted once per ROP

Per HSTAR 8271, SAC was unable to process the map at 193/012419Z
with FGS data. A map was processed at 193/0144Z with small errors.

There was a STIS EMC re-try at 194/004159Z. ROP NS-12 was utilized
at 194/0111Z to rest the STIS flight software error counter.

CCS string “A” was configured as the prime string at 194/0124Z.


Continuation of normal science observations and calibrations.

SpaceRef staff editor.