HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2421

PERIOD COVERED:  0000Z (UTC) 07/23/99 - 0000Z (UTC) 07/26/99

Daily Status Report as of 207/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Seven 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 Five 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.  

   1.4 Completed STIS/CCD/MA1/MA2 8035 (Atmospheric Structure of Hybrid Giants)

       The Space Telescope Imaging Spectrograph (MA1, MA2 and CCD) was used to
make ultraviolet observations of the hybrid giant star HD150798 (a.k.a., Alpha
TrA) in order to study the structure of its atmosphere.  This is one of the
brightest hybrid-chromosphere stars.  A wavelength calibration image was also
taken.  The observations were executed as scheduled, and no anomalies were
noted.  

   1.5 Completed Seven Sets of 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.  

   1.6 Completed 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. 

   1.7 Completed Two Sets of STIS/CCD 8202 (Bright Quasar Close Lensing Search)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of HCLQ0004-4 and HCLQ1444-1 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.  The observations
were executed as scheduled, and no anomalies were noted.  

   1.8 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.  

   1.9 Completed STIS/CCD 8037 (STIS Coronographic Imaging of Circumstellar
Discs)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
coronographic observations of the circumstellar protoplanetary disk around the
star Fomalaut (a.k.a., Alpha PsA, or HD177724).  The observations were executed
as scheduled, and no anomalies were noted.  

   1.10 Completed WF/PC-2 8345 (Multipolar Bubbles and Jets in Very Low
Excitation Planetary Nebulae - A WF/PC-2 H-Alpha Imaging Survey)

       The WF/PC-2 was used to make H-Alpha observations of the very low
excitation planetary nebula PK015+03D1 in order to study its multipolar bubbles
and jets.  Comparison of the morphology of this young PNe sample with more
evolved PNe populations will set new constraints on models for the production
of jet-like outflows and nebular evolution.  The observations were completed as
planned, and no problems were reported.  

   1.11 Completed WF/PC-2 8192 (A Snapshot Survey of Probable Nearby Galaxies)
       The WF/PC-2 was used to make a snapshot survey images of a probable
nearby galaxy KK109.  The census of galaxies in the Local Volume of space is
very incomplete, particularly at the faint end.  The observations were executed
as scheduled, and no anomalies were noted  

   1.12 Completed Two Sets of WF/PC-2/STIS/CCD 8018 (Demographics of Nuclear
Black Holes)

       The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were used
to make observations to study the nuclear region of the normal galaxy M-31 in
order to study the demographics of black holes.  Detection of supermassive
black holes in normal galaxies is one of the grand challenges that HST was
designed to meet.  A wavelength calibration observation and a CCD flat were
also taken.  The observations were executed as scheduled, and no anomalies were
noted.  

   1.13 Completed Two Sets of WF/PC-2 8053 (WF/PC-2 Cycle-7 Earth Flats -- Part
II)

       The WF/PC-2 was used to take Earth flat calibration images.  This
proposal obtains sequences of Earth streak flats to construct high quality flat
fields for the WF/PC-2 filter set.  The observations were executed as
scheduled, and no anomalies were noted.  

   1.14 Completed STIS/MA2 7359 (Chemical Abundances in QSO Broad Absorption
Line Regions)

       The Space Telescope Imaging Spectrograph (MA2) was used to make
observations of the quasar Q2111-4335in order to study the 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.  

   1.15 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 photoionisation and
radiative transfer in gaseous nebulae.  The observations were completed as
planned, and no anomalies were reported.  

   1.16 Completed Two Sets of STIS/CCD/MA1/MA2 7349 (Far UV Echelle
Spectroscopy of Ejecta in SN1006)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used to
make ultraviolet Echelle spectrographic observations of STAR-1503.  The ejecta
of the remnant of the Type Ia Supernova 1006 can be studied in a unique way,
through the broad, high velocity absorption features it causes in the spectrum
of an OB subdwarf star fortuitously located behind the remnant.  The
observations were completed as planned, and no anomalies were reported.  

   1.17 Completed WF/PC-2 7265 (The Metallicity Distribution of the Globular
Cluster Systems of Giant Elliptical Galaxies)

       The WF/PC-2 was used to make observations of the globular clusters,
which are located in galaxy NGC-6166. This is to study the metallicity
distribution of this system.  These observations will have a significant impact
on our understanding of the origin and nature of globular cluster systems in
galaxies.  The observations were completed as planned, and no problems were
reported.  

   1.18 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.  

   1.19 Completed Two sets of STIS/CCD/MA1 8287 (A Search For Transparent Lines
of Sight With Intergalactic He-II Absorption Towards 26 Bright z > 2.9 Quasars)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
He-II absorption line observations of quasars HS1330+255 and HE1312-305.  The
aim is to identify more suitable bright objects for detailed studies of
intergalactic He-II absorption at a redshift of Z <2.9 and >3.2 .  A wavelength
calibration observation was also taken.  The observations were executed as
scheduled, and no anomalies were noted.  

   1.20 Completed WF/PC-2 8310 (White Dwarf Distances to Globular Clusters and
the RR-Lyrae Luminosity Calibration  M-5.)

       The WF/PC-2 was used to make observations of NGC-5904 (a.k.a., M-5) in
order to study its white dwarf and RR-Lyrae class starts.  Despite the efforts
of Hipparcos, the RR-Lyrae absolute magnitude calibration, M_V{RR}, remains
uncertain at a level which critically compromises these stars' use as standard
candles.  The observations were executed as scheduled, and no anomalies were
noted.  

   1.21 Completed WF/PC-2 8538 (Hubble Heritage Observations of Hickson Compact
Galaxy Group 87)

       The WF/PC-2 was used to make Hubble Heritage observations of the Hubble
Compact Group #87.  The sequence of star formation mapped spatially throughout
this group may be the best opportunity to sequence the interplay between
interactions and the different levels of star formation, acting from the tidal
debris in through the central engines of these galaxies.  The observations were
completed as planned, and no anomalies were reported.  

   1.22 Completed STIS/MA1 8103 (A Global Picture of White Dwarfs in
Cataclysmic Variables)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
ultraviolet spectrographic observations of the white dwarf star that is located
in the cataclysmic variable star system known as EK-Tra.  The observations were
executed as scheduled, and no problems were reported.  

   1.23 Completed WF/PC-2 8251 (The Second-Parameter Effect in Metal- Rich,
Globular Clusters: A Snapshot Study of NGC 6441)

       The WF/PC-2 was used to observe the newly- discovered hot horizontal
branch (HB) populations in the metal-rich globular clusters (GCs) NGC 6388 and
NGC 6441 providing an unique opportunity for unraveling the second-parameter
effect.  While it has long been known that at least one parameter besides the
metallicity, Fe/H, determines the HB morphology of GCs, our ignorance as to the
nature of this second parameter {or parameters} has been a major stumbling
block in understanding the formation history and age of the GC system.  The
proposal completed nominally with no reported problems.

   1.24 Completed FGS 8292 (Calibrating the Mass-Luminosity Relation at the End
of the Main Sequence)

       The Fine Guidance Sensor (FGS1R) was used to make astrometric
observations of the star GJ1215 and other nearby reference stars.  This is part
of a study to calibrate the mass-luminosity relation for stars less massive
than 0.2 Msun, with special emphasis on objects near the stellar/brown dwarf
border.  The observations were completed as planned, and no problems were
reported.  

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions: 

                            Scheduled Acquisitions : 19
                                        Successful : 19

                          Scheduled Reacquisitions : 28
                                        Successful : 28

   2.2 FHST Updates: 

                              Scheduled : 53
                             Successful : 53

   2.3 Operations Notes: 

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

       The SM3A SMGT - System Compatability Test was successfully conducted
from 7/23 until 7/25.  All test objectives were met.

3.0 SIGNIFICANT FORTHCOMING EVENTS: 

       Continuation of normal science observations and calibrations.

/DMH