HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2426

PERIOD COVERED:  0000Z (UTC) 07/30/99 - 0000Z (UTC) 08/02/99

Daily Status Report as of 214/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Five Sets of WF/PC-2 8443 (WF/PC-2 Cycle-8 Supplemental Darks
pt1/3)

       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
observations were completed as planned, and no problems were reported.  

   1.2 Completed Five 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.  

   1.3 Completed STIS/CCD 8123 (Testing the Stellar Dynamics of Nested Bars in
NGC 5728)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of the barred galaxy NGC-5728.  Near infrared images of this
barred galaxy reveal the existence of an inner bar, twisted by a large angle
relative to its primary bar.  A wavelength calibration image was also taken. 
The observations were executed as scheduled, and no anomalies were noted.  

   1.4 Completed WF/PC-2 8090 (POMS Test Proposal: WF-II Parallel Archive
Proposal Continuation)

       The WF/PC-2 was used in the parallel mode to make some low galactic
latitude archive observations.  The program will be used to take parallel
images of random areas of the sky.  The observations were executed as
scheduled, and no anomalies were noted.  

   1.5 Completed Five Sets of STIS/CCD 8202 (Bright Quasar Close Lensing
Search)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of HCLQ2225-1, HCLQ2227-2, HCLQ0406-4, HCLQ1324-0 and HCLQ2037-3
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 HSTAR 7207, the acquisition for the
fourth 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.  

   1.6 Completed WF/PC-2 8054 (WF/PC-2 Linear Ramp Filters Calibration)

       The WF/PC-2 was used to make observations of NGC-1976 in order to
execute a series of linear ramp filter calibrations.  The observations were
completed as planned, and no problems were reported.  

   1.7 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.  As described in HSTAR
7207, the acquisition for the second iteration of this proposal failed and the
take data flag remained down.  Otherwise, the observations were executed as
scheduled, and no further anomalies were reported.  

   1.8 Completed Two Sets of STIS/CCD 8406 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal Continuation V)

       The Space Telescope Imaging Spectrograph (CCD) was used to make high
galactic latitude observations taken in parallel with the prime science
observations as part of a POMS proposal.  This is a STIS non-scripted parallel
Condition V proposal.  The observations were completed as scheduled, and no
anomalies were reported.  

   1.9 Completed WF/PC-2 8332 (A Snapshot Survey of Symbiotic Stars)

      The WF/PC-2 was used to make observations of the star HD149427 as part of
a snapshot survey of symbiotic stars.  A fuller understanding of the symbiotic
star phenomenon is important to several branches of present day astrophysics
including mass loss, accretion onto compact objects, and photoionization and
radiative transfer in gaseous nebulae.  The observations were completed as
planned, and no anomalies were reported.  

   1.10 Completed Three Sets of STIS/MA1 8426 (Cycle 8 MAMA Dark Measurements)

       The Space Telescope Imaging Spectrograph (MA1) was used to make a
routine Cycle-8 MAMA dark noise calibration measurement.  This proposal will
provide the primary means of checking on the health of the MAMA detectors. 
This is done through frequent monitoring of the background count rate.  The
observations were completed as planned, and no problems were reported.  

   1.11 Completed Three Sets of STIS/MA2 7359 (Chemical Abundances in QSO Broad
Absorption Line Regions)

       The Space Telescope Imaging Spectrograph (MA2) was used to make
observations of the quasars Q1239+0028, Q1212+1445 and Q1235+1803 in order to
study their chemical abundances in the QSO’s broad absorption line regions. 
These observations are designed to test the possible models for high
metallicity in BALQSOs and, indirectly, test the origins of the BAL
phenomenon.  A wavelength calibration image was also taken.  The observations
were completed as planned, and no anomalies were reported.  

   1.12 Completed STIS/CCD/MA2 8225 (Absorption and Obscuration in Radio-Loud
Quasars)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
observations of the radio-loud MRC1202-26.  The role of associated absorption
systems and dust obscuration close to the central engines of AGN is not
understood.  The observations were completed as planned, and no anomalies were
reported.   

   1.13 Completed Two Sets of WF/PC-2 8436 (POMS Test Proposal: WFII Backup
Parallel Archive Proposal II)

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

   1.14 Completed STIS/CCD/MA1/MA2 7389 (Chromospheres and Transition Layers in
Hyades and Pleiades F Stars)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used to
make observations of the F class star HD28033 which is located in the Hyades
star cluster.  This proposal seeks to obtain additional empirical constraints
on the heating mechanisms for stellar chromospheres, transition layers and
coronae.  A wavelength calibration obseration was also taken.  The observations
were completed as planned, and no problems were reported.

   1.15 Completed Two Sets of STIS/CCD 8271 (A Snapshot Survey of LMC Planetary
Nebulae: A Study of Nebular and Late Stellar Evolution)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
medium-resolution slitless spectroscopy snapshot images of the planetary
nebulae LMC-SMP-95 and LMC-SMP-94 that are located in the Large Magellanic
Cloud in order to study the parallel evolution of the nebulae and their central
stars.  The observations were completed as planned, and no problems were
reported.  

   1.16 Completed STIS/CCD 8539 (Using the Impact of the Lunar Prospector into
a South Polar Cold Trap to Detect Water Ice on the Moon)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations the Lunar Prospector impact site that is located near the South
Lunar Pole.  A controlled impact of the orbiter into a polar crater was used to
liberate a small amount of water vapor that may be detected by ground- and
space-based observatories.  A wavelength calibration image was also taken.  The
observations were executed as scheduled, and no anomalies were reported.  

   1.17 Completed STIS/MA1 8295 (Anomalously Blue Giants: Possible Precursurs
to Subdwarf B Stars)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
observations of the galaxy NGC-6791.  Confirmation of the presence of hot
companions would lend strong support to the theory that the anomalous giants
are the binary precursors to the sdB class of stars.  The observations were
completed as planned, and no problems were reported.

   1.18 Completed STIS/CCD/MA2 8342 (Abundances in Halo Stars and Galactic
Element Formation)

       The Space Telescope Imaging Spectrograph (MA2 and CCD) was used to make
observations of star HD122956 as part of a study of the abundances in halo
stars and galactic element formation.  The results for the very oldest galactic
stars will also provide an important, and independent, age determination for
the Galaxy and hence constrain cosmological age estimates.  A wavelength
calibration image was also taken.  The observations were executed as scheduled,
and no anomalies were noted.

1.19 Completed STIS/CCD 8418 (CCD Sensitivity Monitor C8)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of standard source AGK+81D266 as part of a CCD
sensitivity-monitoring program in Cycle-8.  The sensitivity of each CCD grating
mode is monitored to detect any change due to contamination or other causes.  A
wavelength calibration image was also taken.  The observations were completed
as planned, and no anomalies were reported. 

   1.20 Completed STIS/CCD/WF/PC-2 7388 (Black Holes and the Centers of
Galaxies)

       The Space Telescope Imaging Spectrograph (CCD) and the WF/PC-2 were used
to continue our survey of the center of nearby galaxy NGC-4697.  The major goal
is to survey an unbiased set of galaxies with a potentially wide range of black
hole masses.  The sample has been carefully chosen to optimize leverage on the
character of a proposed correlation of black hole mass with galaxy mass.  A
wavelength calibration image was also taken.  The observations were completed
as scheduled with no anomalies.


   1.21 Completed FGS 8440 (The Mass of the Classical Cepheid ADS 14859 Cycle
8)

       The Fine Guidance Sensors were used to make astrometric observations of
the binary Cepheid star ASD14859 in order to determine the Cepheid star’s
mass.  The determination of accurate masses for Cepheid variable stars is
required for quantitative understanding of these primary distance indicators,
and also for the related questions of the accuracy of evolutionary calculations
and the role-played by massive stars in galactic evolution.  The observations
were completed as scheduled, and no anomalies were reported.  


   1.22 Completed WF/PC-2 8134 (Is the IMF Universal at Low Stellar Masses?)

The WF/PC-2 was used to make observations of the cluster NGC-2214 (a.k.a., LMC
cluster R-136).  Only the HST can provide the resolution and limiting magnitude
required to reach the low-mass end of the IMF at extragalactic distances.  The
observations were executed as scheduled, and no problems were reported.
   1.23 Completed Two Sets of STIS/CCD 7912 (STIS Parallel Archive Proposal -
Nearby Galaxies - Imaging and Spectroscopy)

       The Space Telescope Imaging Spectrograph (CCD) was used to make parallel
observations of nearby galaxies.  This survey will be useful to study the star
formation histories, chemical evolution, and distances to these galaxies. 
These data will be placed immediately into the Hubble Data Archive.  The
observations were completed as scheduled, and no problems were reported.  

   1.24 Completed STIS/CCD 8470 (POMS Test Proposal: STIS Non-Scripted Parallel
Proposal Continuation V)

       The Space Telescope Imaging Spectrograph (CCD) was used to make high
galactic latitude observations taken in parallel with the prime science
observations as part of a POMS proposal.  This is a STIS non-scripted parallel
Condition VI proposal.  The observations were completed as scheduled, and no
anomalies were reported.  

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions: 

                            Scheduled Acquisitions : 25
                                        Successful : 24

       Per HSTAR 7207, the acquisition scheduled for 212/070654Z failed when
the scan step limit was exceeded on FGS-3.  The observations described in 1.5
and 1.7 were affected.

                          Scheduled Reacquisitions : 23
                                        Successful : 23

   2.2 FHST Updates: 

                              Scheduled : 72
                             Successful : 72

   2.3 Operations Notes: 

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

       HSTAR 7209 describes two status buffer messages at 212/100003Z
indicating that the SSM and the SI C&D were “out of sync” with respect to the
observing time line.  The message means that either a scan, offset or peakup
scan was rejected.  This caused no immediately reportable effect on the ongoing
observations.  Subsequently, ROP NS-5 was utilized at 212/1145Z to clear the SI
C&DH status buffer errors.

       At 212/100712Z, four FGS star selector positions flagged out of limits. 
HSTAR 7208 was written.

       The STIS MCE2 reset at 213/065700Z while the low voltage was on and
while in an SAA interval.  Per ROP NS-12 the STIS flight software error counter
was reset at 213/0755Z.  MAMA-2 was recovered via the SMS at 213/1530Z, the
time of the next commanded high voltage on commanding.

3.0 SIGNIFICANT FORTHCOMING EVENTS:
 
       Continuation of normal science observations and calibrations.

/DMH