Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/ftp/observing/status_reports/old_reports_98/hst_status_08_31_98 Дата изменения: Mon Aug 31 15:24:43 1998 Дата индексирования: Sun Dec 23 10:57:41 2007 Кодировка: Поисковые слова: ngc 5128

HUBBLE SPACE TELESCOPE

DAILY REPORT #2198

PERIOD COVERED: 0000Z (UTC) 08/28/98 - 0000Z (UTC) 08/31/98

Daily Status Report as of 243/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

1.1 Completed Five Sets of STIS/CCD 8062 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal Continuation)

The Space Telescope Imaging Spectrograph (CCD) was used to make high
galactic latitude observations take in parallel with the prime science
observations. The observations were completed as planned, and no problems
were reported.

1.2 Completed Four Sets of NIC/2/3 7907 (NICMOS Pure Parallel Winter 97-98)

The Near Infrared Camera (Cameras Two and Three) was used to make
pure parallel spectrographic observations of sky regions when another
instrument is prime. The observations were completed as planned, and no
anomalies were reported.

1.3 Completed Four Sets of NIC/2/3 8063 (NICMOS Pure Parallel Sponge -
Backup)

The Near Infrared Camera (Cameras Two and Three) was used to make
observations taken in parallel with the prime science observations. This
proposal is PRE-the new FOM default. The observations were executed as
scheduled, and no anomalies were noted.

1.4 Completed Nine Sets of WF/PC-2 7712 (WF/PC-2 Cycle 7 Supplemental
Darks pt2/3)

The WF/PC-2 was used to make a series of Cycle 7 supplemental
calibration darks. This dark calibration program obtains three dark frames
every day to provide data for monitoring and characterizing the evolution
of hot pixels. During the fourth, fifth and sixth iterations, the
acquisition and reacquisition failures described in HSTAR 6442 and 2.1
occurred, affecting three observations. Otherwise, the observations were
executed as scheduled, and no further anomalies were noted.

1.5 Completed Six Sets of STIS/CCD 7948 (CCD Dark and Bias Monitor --
Cont. to Dec. 98)

The Space Telescope Imaging Spectrograph (CCD) was used to measure
CCD dark current and bias rates for the two supported amplifier settings
{GAIN=1 and GAIN=4} in order to gather data for making superdarks and
superbiases. The data will be used to track the growth of hot pixels on
the CCD in general and within the various target acquisition apertures
specifically. During the third and fourth iterations, the acquisition and
reacquisition failures described in HSTAR 6442 and 2.1 occurred, affecting
two observations. Otherwise, the observations were executed as scheduled,
and no further anomalies were noted.

1.6 Completed NIC/1/2/3 7874 (The Shells of NGC 5128: Debris from a
Recent Merger)

The Near Infrared Camera (Camera One, Two and Three) was used to
make observations of the shells of NGC-5128. At a distance of about 3.6
Mpc, NGC 5128 {= Cen A} is the closest high-luminosity AGN, the closest
radio galaxy, the closest giant elliptical and one of the closest and best
examples of a merger remnant. The observations were completed as planned,
and no anomalies were reported.

1.7 Completed NIC/1/2/3 7849 (Metallicity and the Cepheid Distance Scale)

The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of Cepheid variable stars in the M-31 galaxy. The local
distance scale to galaxies is largely based on the Cepheid
period-luminosity relation. Motivated by the goal of measuring an accurate
value of the Hubble constant, HST has been used successfully to discover
scores of Cepheid variables in each of about 20 galaxies. The observations
were executed as scheduled, and no anomalies were noted.

1.8 Completed Two Sets of NIC/2 7894 (Completing A Near-Infrared Search
for Very Low Mass Companions to Stars within 10 pc)

The Near Infrared Camera (Camera Two) was used to make observations
searching for very low mass (VLM) companions to the star HD10780. This
search will be the largest, most sensitive, volume-limited search for VLM
companions ever undertaken. The observations were completed as planned,
and no anomalies were reported.

1.9 Completed WF/PC-2 7386 (A Snapshot Survey of Nova Shells)

The WF/PC-2 was used to make observational images of the super nova
shell V992-SCO in order to detect and measure its expanding gaseous shell.
These observations will trace the distribution of hot and cool gas in the
nova shells, and show their degree of inhomogeneity on both large and small
scales. The observations were completed as scheduled, and no problems were
noted.

1.10 Completed FGS 7677 (Monitor the Long Term Stability of FGS-3)

The goal of these measurements is to monitor the internal positional
stability of FGS3 by measuring many stars in the M35 check field repeatedly
over a one year period. The results of these measurements are the
stability characteristics of FGS3 which allow an estimate of differential
corrections to OFAD and plate scale. The measurements were completed as
scheduled. with no reported anomalies.

1.11 Completed Four Sets of WF/PC-2 7909 (POMS Test Proposal: WF II
Parallel Archive Proposal)

The WF/PC-2 was used to make parallel observations as part of the
POMS test proposal. This test proposal is designed to simulate scientific
plans. The observations were completed as planned, and no problems were
reported.

1.12 Completed Three Sets of NIC/1/2/3 7827 (The Structure of
Circumbinary Material in Multiple T-Tauri Systems)

The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of the T-Tauri class systems UY-Aur, DK-Tau and FV-Tau to
study their structures of circumbinary material. Recent studies of T-Tauri
populations in nearby star forming clouds have shown that the majority of
stars exist in multiple {binary or higher} systems. During the first
iteration of this proposal, the fine lock default to control on one FGS
only (described in HSTAR 6641 and section 2.1) occurred. Then, during the
second iteration, the acquisition and reacquisition failures described in
HSTAR 6442 and 2.1 occurred, affecting seven observations. Otherwise, The
observations were completed as planned, and no further problems were
reported.

1.13 Completed NIC/1/2/3 7250 (Ionized Tails From Supergiants at the
Galactic Center)

The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of the ionized tail on the supergiant star F15307+325
which is located near the galactic center. The strong ultraviolet field at
the galactic center is capable of ionizing the winds from late-type
supergiants. The observations were executed as scheduled, and no anomalies
were noted.

1.14 Completed Two Sets of NIC/2 7835 (A Search for Superplanets
Embedded in Beta Pic & Vega-like Circumstellar Disks)

The Near Infrared Camera (Camera Two) was used to make observations
of the circumstellar disk around star HD18978 in order to search for
superplanets. The discovery of a circumstellar disk orbiting Beta Pictoris
as well as the discovery of other similar IR-excess Vega-like systems have
provided compelling evidence that our solar system, or at least many of the
processes which are thought to have created it, may be far from unique.
The observations were executed as scheduled, and no anomalies were noted.

1.15 Completed Three Sets of STIS/CCD 8064 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal - Backup)

The Space Telescope Imaging Spectrograph (CCD) was used to conduct a
non-scripted parallel POMS test. The observations were completed as
scheduled, and no problems were reported.

1.16 Completed WF/PC-2 6672 (Unveiling the Massive Star Content in the
Prototypical Nuclear Starburst NGC-7714)

The WF/PC-2 was used to make observations of the starbursting region
of the prototypical nuclear galaxy NGC-7714. The compact appearance and
the brightness of the nuclear starburst, as well as the amount of
multiwavelength observational data, lead us to propose this object as a
laboratory to study the star formation processes in the violent nuclei of
starburst galaxies. The observations were executed as scheduled, and no
anomalies were noted.

1.17 Completed NIC/2 7834 (A Search for Giant Planets Around Very Young
Nearby Late-type Dwarfs)

The Near Infrared Camera (Camera Two) was used to make observations
of the very young, late-type, dwarf star SAO91772 as part of a search for
large planets. Very young late-type dwarfs at distances closer than 30 pc
are excellent sites to provide a direct detection of extrasolar planets.
The observations were executed as scheduled, and no anomalies were noted.

1.18 Completed NIC/1/2/3 7886 (NICMOS Snap Shot Survey of Early-Type
Galaxies)

The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of the early-type galaxy NGC-1172 as part of a snap-shot
broad-band imaging survey. Since almost all early-type galaxies harbor
dust, these images which are less sensitive to extinction and will provide
superior light profiles for dynamical studies of the cores of these
galaxies. The observations were completed as scheduled, and no problems
were reported.

1.19 Completed NIC/2 7887 (A Survey of Gravitational Lenses as
Cosmological Tools II)

The Near Infrared Camera (Camera Two) was used to make observations
of the gravitational lens candidate system Q2345+007. The propose is to
extend our IR survey of gravitational lenses and gravitational lens
candidates by obtaining NICMOS images of 14 additional lens systems or
candidates. The observations were executed as scheduled, and no anomalies
were noted.

1.20 Completed NIC/2 7413 (The Dusty Environments of Protostars)

The Near infrared Camera (Camera Two) was used to make observational
images of the dusty environment around protostar IRAS0481. These
observations will address physical conditions in protostellar envelopes and
provide deeper insight into star and protoplanetary disk formation. The
observations were completed as planned, and no problems were noted.

1.21 Completed Two Sets of NIC/2 7227 (A Search for Low
Mass/Sub-Luminous Companions to M-Stars)

The Near Infrared Camera (Camera Two) was used to make a search for
low mass/sub-luminous companions to low mass M class stars. Knowledge of
stellar and sub-stellar masses and luminosities at and below the ~0.08
M{sun} H-burning limit is of fundamental importance. A dark calibration
image was also taken. The observations were completed as planned, and no
problems were reported.

1.22 Completed NIC/1/2/3 7882 (Molecular Gas in the Centers of Arp220
and NGC6240: Nuclear Accretion Disks?)

The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of the molecular cloud in the center of the
ultraluminous, infrared galaxy IC4553. Combined with existing ground-based
spectroscopy, the HST will provide the information required for
understanding the dynamical state of these regions. The observations were
executed as scheduled, and no problems were reported.

1.23 Completed NIC/2 7329 (The Nature of the Damped LyAlpha Absorbers --
A New Study of Young Galaxies)

The Near Infrared Camera (Camera Two) was used to make observations
of the young galaxy Q1500+0824 in order to study the nature of its damped
Lyman-Alpha Absorbers (DLAs). The damped Lyman-Alpha absorption line
systems, occasionally found in quasar spectra, provide one of only a few
practical methods of detecting and studying significant numbers of galaxies
at high redshifts. The observations were executed as scheduled, and no
anomalies were noted.

1.24 Completed WF/PC-2 7501 (Expansion Parallax Distances to Planetary
Nebulae)

The WF/PC-2 was used to make parallax distance measurements of the
planetary nebula IC1454. The largest impediment to our understanding of
planetary nebulae is the lack of reliable distances. Acquired by
generalized statistical methods in all but a handful of cases, individual
PNe distances are often uncertain by factors of two or more. The
observations were executed as scheduled, and no anomalies were noted.

1.25 Completed STIS/CCD/MA1 7734 (UV Eclipse Spectroscopy of Accretion
Disk Winds)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations of the eclipsing binary star UX-UMa in order to study its
accretion disk winds. This will probe its ionisation structure as well as
its geometry and kinematics. The observations were completed as planned,
and no problems were reported.

1.26 Completed WF/PC-2 7387 (T-Tauri Star Snapshot Survey)

The WF/PC-2 was used to make observations of the star CW-Tau as part
of a T-Tauri class star survey. The observations were executed as
scheduled, and no anomalies were noted.

1.27 Completed NIC/1 7833 (Multiplicity Survey of Alpha Persei: Studying
the Evolution and Effects of Companions)

The Near Infrared Camera (Camera One) was used to make observations
of the star Alpha-Persei. Extensive observations have established that
binaries are twice as common amongst pre-main sequence stars than older
solar neighborhood G-dwarfs. The observations were executed as scheduled,
and no anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions : 37
Successful : 36

As documented in HSTAR 6641, the acquisition at 240/2200Z failed to
fine lock on FGS-1 only. The attitude for the FHST map at 240/2208Z looked
good but the roll update at 240/2148Z failed. The proposal described in
1.12 may have been affected.

HSTAR 6642 describes an acquisition failure that occurred at
214/0015Z, when both the scan step and the search radius flags did not get
set, as well as a subsequent re-acquisition failure. Proposals described
in 1.4, 1.5, and 1.12 were affected.

Scheduled Reacquisitions : 17
Successful : 16

2.2 FHST Updates:

Scheduled : 50
Successful : 49

See 2.1 for details of the update failure.

2.3 Operations Notes:

Using ROP SR-1, the SSR EDAC error counter was reset eleven times.

Starting today, for the next six days, all commanding and telemetry
will be processed using the IP. The legacy system, configured as "hot
backup", will be collecting telemtry.

At 242/060256Z, the NICMOS EDAC single bit error counter incremented
to 7. The NICMOS internal log was dumped at 242/083151Z and the limit for
the parameter was adjusted per an operaions request. HSTAR 6643 was
written.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.

/DMH