HUBBLE SPACE TELESCOPE

       DAILY REPORT #2545

PERIOD COVERED:  0000Z (UTC) 01/21/00 - 0000Z (UTC) 01/24/00

Daily Status Report as of 024/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Three Sets of STIS/CCD 8409 (STIS CCD Bias Monitor C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to make a 
CCD bias calibration observation.  This is to monitor the bias in the 1x1, 
1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up 
high-S/N superbiases and to track the evolution of hot columns.  The 
observations were executed as scheduled, and no anomalies were reported.

    1.2 Completed Two Sets of STIS/CCD/MA1 8285 (Using STIS to Unravel 
Planetary Nebulae)

        The Space Telescope Imaging Telescope (CCD and MA1) was used to 
make new STIS observations to study the UV/visible light properties of the 
young planetary nebula NGC 7027 and other objects in this class that 
display remarkable complexity which has prevented a full understanding of 
post-asymptotic giant branch stellar evolution.  The observations completed 
nominally.

    1.3 Completed Four Sets of STIS/CCD 8408 (STIS CCD Dark Monitor C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to make a 
CCD bias calibration observation.  This is to monitor the darks for the 
STIS CCD.  The observations were executed as scheduled, and no anomalies 
were reported.

    1.4 Completed STIS/CCD 8163 (Trapezium Systems and Stellar Jets in 
30-Doradus)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
observations of the 30-Doradus system (both the North and South 
sections).  30-Doradus is the nearest and best resolved extragalactic 
starbursting region.  The observations were completed as scheduled, and no 
anomalies were reported.

    1.5 Completed STIS/MA2 8429 (Cycle 8 Plate Scale Verification)

        The Space Telescope Imaging Spectrograph (MA2) was used to conduct 
a Cycle-8 plate scale calibration verification. The calibration was 
completed as scheduled, and no anomalies were reported.

    1.6 Completed WF/PC-2 8183 (Morphology of the Most Massive Galaxies in 
the Early Universe)

        The WF/PC-2 was used to make observations of the massive radio 
galaxy MRC324-22 in order to study its morphology.  High redshift radio 
galaxies are fundamentally important probes of galaxy and cluster 
formation.  The observations were completed as scheduled, and no anomalies 
were reported.

    1.7 Completed Four Sets of STIS/MA2 8509 (NUV MAMA Darks)

        The Space Telescope Imaging Spectrograph (MA2) was used to 
determine the health of the FUV MAMA detector by monitoring the background 
count rate.  The observations completed with no reported problems.

    1.8 Completed WF/PC-2 8548 (Hubble Heritage Observations of NGC 1999)

        The WF/PC-2 was used to make broad band images of the reflection 
nebula NGC 1999 as part of the Hubble Heritage program.  Short narrow band 
images will be made of the binary central star.  The proposal completed 
with no reported problems.

    1.9 Completed WF/PC-2 8239 (Imaging the NLR in a Complete Sample of 
z<0.5 Radio-Quiet PG Quasars)

        The WF/PC-2 was used to observe quasar PG1049-005 and to determine 
its role in the evolution of galaxies, where a central engine leaves its 
visible imprints in the galaxy through strong ionization and heating of the 
ISM.  The observations completed with no reported problems.

    1.10 Completed Three Sets of STIS/CCD 8202 (Bright Quasar Close Lensing 
Search)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
observations of HCLQ1123+0, HCLQ0504-2 and HCLQ1008+3 as part of a second 
generation survey to search for bright lensing quasars.  With the restored 
PSF, new images will be considerably more sensitive to the presence of both 
close separation and faint lens components, and because STIS reaches two 
magnitudes fainter the PC, the new snapshot images will have much greater 
dynamic range.  As described in 2.1 and HSTAR 7482, the acquisition for the 
final iteration of this proposal failed, and the take data flag remained 
down.  Otherwise, the observations were executed as scheduled, and no 
further anomalies were noted.

    1.11 Completed Two Sets of WF/PC-2 8199 (Local Cosmology: The Nearby 
Flow Field and its Structure)

        The WF/PC-2 was used to make observations of the galaxies IRAS12483 
and UGC03974 in order to study their nearby flow field and structure.  Very 
little data are available to constrain the velocity field of galaxies in 
the local neighborhood {<= 500 km/sec}.  The observations were executed as 
scheduled, and no anomalies were noted.

    1.12 Completed STIS/CCD/MA1/1 8109 (Determination of the SED for TON 
S180: A Direct Probe of the Big Blue Bump)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to observe the Seyfert 1 galaxy, TON S180, the brightest AGN in the 
extreme UV regime.  There is a low galactic column along the line-of-sight 
with no evidence for intrinsic absorption.  This offers a rare opportunity 
to obtain the spectral-energy- distribution {SED} of the source, including 
data from the vital soft X-ray to UV range which is generally difficult to 
observe due to absorption of those photons by Galactic material.  The 
observations were completed with no anomalous activity.

    1.13 Completed WF/PC-2 8124 (The Stellar Initial Mass Function of 
Globular Clusters)

        The WF/PC-2 was used to observe the mass functions of homogeneous 
old stellar populations.  Those for which reliable mass functions have been 
determined already, however, have generally been subject to dynamical 
evolution {relaxation, escape of stars, and tidal shocks}, so that the 
observed mass function is not primordial.  We have therefore examined 
tables of properties of globular clusters in order to choose those that are 
least likely to have suffered from relaxation, escape, and tidal 
shocks.  There were no reported problems.

    1.14 Completed STIS/MA1 8510 (FUV MAMA Darks)

        The Space Telescope Imaging Spectrograph (MA1) was used to 
determine the health of the FUV MAMA detector by monitoring the background 
count rate.  The observations completed with no reported problems.

    1.15 Completed STIS/MA1 8428 (STIS FUV-MAMA Cycle 8 Flats)

        The Space Telescope Imaging Spectrograph (MA1) was used to make a 
series of far-ultraviolet calibration flats with the Kr lamp for the 
construction of on-orbit D-flats for select modes.  The calibration images 
were completed as planned, and no problems were reported.

    1.16 Completed Three Sets of WF/PC-2 8281 (The Spatial and Ionization 
Structure of Cas A's Metal-Rich Ejecta)

        The WF/PC-2 was used to observe Cassiopeia A {Cas A}, the prototype 
for the class of young, oxygen-rich SNRs containing material moving at 
several thousand km s^-1 and exhibiting extreme O and Si-group {Si, S, Ar, 
and Ca} abundances due to nuclear processing in a massive star. Several 
basic properties of the remnant are not well understood including shock 
dynamics of the ejecta, UV and optical line emission mechanisms, and the 
puzzling organization of its optical knots into large ring-like 
structures.  No problems were reported during execution.

    1.17 Completed STIS/CCD/MA1 8273 (The Oxygen Abundance in Translucent 
Interstellar Clouds)

        The Space Telescope Imaging Telescope (CCD and MA1) was used to 
obtain high-resolution STIS echelle observations of the interstellar O I 
Lambda1356 absorption toward a sample of starsbehind six translucent clouds 
characterized by large H I column densities and high extinctions  Previous 
GHRS measurements of this weak feature in diffuse clouds have shown no 
evidence of density-dependent O depletion from the gas phase and indicate a 
total {gas + dust} interstellar O abundance that is about 2/3 of the solar 
value.  The observations were completed nominally.

    1.18 Completed WF/PC-2/STIS/CCD 8255 (Stellar Populations in the 
Closest Large Low Surface Brightness Galaxy)

        The WF/PC-2 and the Space Telescope Imaging Telescope (CCD) were 
used to observe the closest known large low surface brightness galaxy, UGC 
2302, in order to resolve for the first time the massive stars and tip of 
the red giant branch in such a system.  The proposal completed nominally.

    1.19 Completed WF/PC-2 8216 (T Tauri Star Snapshot Survey II. 
Completing the CTTs Sample)

        The WF/PC-2 was used to make observations of the T-Tauri class star 
known as V375-LAC as part of Snapshot Survey II.  This database will be of 
fundamental importance to understanding the nature of planet-forming 
environments and their frequency in the galaxy.  The observations were 
executed as scheduled, and no anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 19
Successful: 19

        The acquisition at 023/215241Z failed when the scan step limit was 
exceeded on FGS-3.  HSTAR 7482 was written.  The proposal described in 1.10 
was affected.
  Scheduled Re-acquisitions: 25
Successful: 25

    2.2 FHST Updates:
Scheduled: 44
Successful: 44

    2.3 Operations Notes:

        Servicing Mission Observatory Verification (SMOV) activities continue.

        Per ROP IC-2 and an operations note, SSA transmitter #2 was turned 
on and off seven times.  Using the same ROP, SSA transmitter #1 was turned 
on and off twice.  ROP IC-1 was used to turn the MA transmitter on and off 
once.

        The SSR EDAC error counter was cleared once, using ROP SR-1A.

        The battery #6 recharge ratio (CSFRRAT6) went out-of-bounds high 
from 021/095130Z until 021/101013Z with a value of 1.27.  The value for the 
previous orbit was 0.85; for the following orbit, 0.97.  HSTAR 7480 was 
written.

        The SI C&DH error counter was reset and reporting enabled at 
024/0306Z as directed by ROP NS-5.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of SMOV and normal science observations and calibrations.

/CAW