HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2348

PERIOD COVERED:  0000Z (UTC) 04/09/99 - 0000Z (UTC) 04/12/99

Daily Status Report as of 102/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed STIS/CCD/MA2 7348 (Boron in the Extreme Pop II Star HD
140283)

       The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
make observations of the extreme POP II dwarf class star HD140283.  Using
the HST and ground-based observations it has been determined that there is
an abundances of boron and beryllium in this star.  A wavelength
calibration image was also taken.  The observations were executed as
scheduled, and no anomalies were noted.

   1.2 Completed Five Sets of WF/PC-2 7713 (WF/P-2 Cycle 7 Supplemental
Darks pt3/3)

       The WF/PC-2 was used to make supplemental dark calibration images.
This dark calibration program obtains 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 anomalies were noted.

   1.3 Completed Six 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.  As described in 2.1 and HSTAR 7096, the
acquisition for the fifth iteration of this proposal defaulted to fine lock
backup on one FGS only.  Otherwise, the observations were executed as
scheduled, and no further anomalies were noted.

   1.4 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.

   1.5 Completed Two Sets of WF/PC-2 6357 (The Nuclear Morphology of
Elliptical Galaxies)

       The WF/PC-2 was used to make images of the early type, large,
elliptical galaxies NGC-4482 and NGC-6357 (taken from a list of 150
galaxies) in order to study their nuclear morphology.  This survey will
complement Illingworth's snapshot study of later Hubble types.  The
observations were completed as scheduled, and no anomalies were reported.

   1.6 Completed WF/PC-2 8399 (Hubble Heritage observations of NGC 4650A)

       The WF/PC-2 was used to make observations of NGC-4650 as part of the
Hubble Heritage observations.  This object is a classic example of a polar
ring galaxy in which an outer disk orbits in approximately the polar plane
of an inner, high surface brightness S0 galaxy.  Polar ring galaxies are
astrophysically important as highly visible examples of the effects of
interactions and/or gas capture in galaxy evolution.  The observations were
executed as scheduled, and no anomalies were noted.

   1.7 Completed WF/PC-2 6555 (What Causes the Astigmatism in Gravitational
Lenses?)

       The WF/PC-2 was used to make observations of the gravitationally
lensed quasar system PG1115+080 in order to study why these systems produce
astigmatic gravitational lenses.  Among multiply imaged quasars, those for
which the shape of the lensing mass can be measured show surprisingly
strong deviations from circular symmetry (i.e., astigmatism in the
gravitational lens).  Although the initial acquisition was successful, the
two subsequent re-acquisitions failed as described in 2.1 and HSTAR 7092,
affecting two observations.  Otherwise, the observations were completed as
planned , and no further problems were reported.

   1.8 Completed WF/PC-2 6480 (The Butcher-Oemler Effect: Where Have All
The Spirals Gone?)

       The WF/PC-2 was used to make observations of the blue disk-type
galaxy A851-POS1 in order to study the Butcher-Oemler effect.  Other
observational data show that mergers and tidal interactions were apparently
more common in younger clusters; these may contribute to the disappearance
of spiral galaxies by the present epoch.  The observations were executed as
scheduled, and no anomalies were noted.

   1.9 Completed Two Sets of STIS/CCD 8081 (STIS CCD Hot Pixel Annealing
[2- II)

       The Space Telescope Imaging Spectrograph (CCD) was used to make a
dark and a bias calibration observation.  The effectiveness of the CCD hot
pixel annealing process is assessed by measuring the dark current behavior
before and after annealing and by searching for any window contamination
effects.  The observations were executed as scheduled, and no anomalies
were noted.

   1.10 Completed WF/PC-2 6967 (Blue Continuum Snapshots of 3CR Radio -
Continued Galaxies)

       The WF/PC-2 was used to make observations of the radio galaxies
3C437.0 and 3C401.0.  Radio galaxies are an important class of
extragalactic objects: they represent one of the most energetic
astrophysical phenomena and they may be used as probes of their
environments.  They are unique probes of the early Universe.  The
observations were completed as planned, and no problems were reported.

   1.11 Completed Two Sets of WF/PC-2 7281 (Snapshot Survey of the B2
Sample of Radio Galaxies)

       The WF/PC-2 was used to make snapshot survey observations of the B2
sample radio galaxies B2+1339+26 and B2+1346+26.  This program is aimed to
answer the following key questions: How common are extended nuclear disks?
What is their orientation and morphology?  How common are optical jets?
The observations were executed as scheduled, and no anomalies were noted.

   1.12 Completed WF/PC-2 6356 (SNAPSHOT Survey of Ultraluminous Infrared
Galaxies)

       The WF/PC-2 was used to make observations of galaxy Gal-185802 as
part of a survey of ultraluminous infrared galaxies.  The nature of
ultraluminous infrared galaxies has generated considerable controversy.
The two main issues are: {1} are they powered by violent bursts of star
formation or by hidden quasars?  {2} are interactions and mergers
invariably involved?  The observations were executed as scheduled, and no
anomalies were noted.

   1.13 Completed STIS/CCD/MA2 7263 (Physical Processes in Stellar
Atmospheres: Comparative Analysis of the Sun and Alpha Cen A)

       The Space Telescope Imaging Spectrograph (CCD and MA2)  were used to
study the physical processes in the stellar atmosphere of Alpha-Cen (a)
(a.k.a., HD128620).  Using this atmosphere along with observed velocity
fields, we will reassess competing theories for various phenomena observed
in solar-type stars.  A wavelength calibration image was also taken.  The
observations were executed as scheduled, and no anomalies were noted.

   1.14 Completed WF/PC-2 8061 (POMS Test Proposal: WF-II Backup Parallel
Archive Proposal)

       This is a POMS test proposal designed to simulate scientific plans.
The proposal was executed as planned, and no anomalies were reported.

   1.15 Completed WF/PC-2/STIS/CCD 7615 (Determination of the Mass Function
of a Globular Cluster Through Gravitational Microlensing)

       The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to make gravitational microlensing observations of the large globular
cluster NGC-6656 located in Sagittarius in order to study its mass
function.  Gravitational microlensing offers a unique and direct method of
determining the masses of stars and other compact objects down to planetary
masses.  A bias and dark calibration observations were also taken.  The
observations were completed as planned, and no problems were reported.

   1.16 Completed WF/PC-2 6354 (Measuring Luminosity Evolution in Z = 0.3
Field Galaxies)

       The WF/PC-2 was used to make snapshot observations of the galactic
cluster Gal-Cluster-1 located at a distance of Z = 0.3.  The targets were
drawn from a much larger pool of galaxies for which the internal kinematics
have been measured from an extensive ground based program.  The
observations were executed as scheduled, and no anomalies were noted.

   1.17 Completed Three Sets of STIS/CCD 7949 (CCD Dark and Bias Monitor --
Cont. to June 99)

       The Space Telescope Imaging Spectrograph (CCD) was used to conduct a
CCD dark calibration and a bias monitoring program.  It was also scheduled
to track the growth of hot pixels on the CCD in general and within the
various target acquisition apertures specifically.  The observations were
executed as scheduled, and no anomalies were noted.

   1.18 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 NGC-3242.  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.

   1.19 Completed WF/PC-2 7273 (The Molecular Torus and Ionized Gas in the
Circinus Galaxy)

       The WF/PC-2 was used to make observations of molecular torus and
ionized gas in the galaxy Curcinus.  In the current AGN paradigm,
distributions of ionized gas in so-called 'ionization cones' are believed
to be produced by shadowing of the central source of ionizing radiation by
a molecular torus.  The observations were completed as scheduled, and no
problems were reported.

   1.20 Completed Eleven Sets of STIS/CCD 8091 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal Continuation)

       The Space Telescope Imaging Spectrograph (CCD) was used to make high
galactic latitude, non-scripted, parallel observations.  As described in
2.1 and HSTAR 7093, the acquisition for the second iteration of this
proposal defaulted to fine lock backup on one FGS only.  Then, as described
in 2.1 and HSTAR 7096, the acquisition for the fourth iteration of this
proposal also defaulted to fine lock backup on one FGS only.  Otherwise,
the observations were completed as planned, and no further anomalies were
noted.

   1.21 Completed STIS/CCD 8393 (POMS Test Proposal: STIS Non-Scripted
Parallel Proposal Continuation IV)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
POMS, non-scripted, low galactic latitude observations made in parallel
with the prime science observations.  The observations were executed as
scheduled, and no anomalies were noted.

   1.22 Completed WF/PC-2 6579 (The Cosmic Velocity of the Great Attractor)

       The WF/PC-2 was used to make observations of the galaxy NGC-5516
which is located in the Centaurus Cluster.  The objective is to measure its
distance, using the "surface brightness fluctuation" method. When combined
with the radial velocity, these measurements will allow the investigator to
determine whether the Centaurus Cluster is falling in to the Great
Attractor.  As described in 2.1 and HSTAR 7093, the acquisition for this
proposal defaulted to fine lock backup on one FGS only.  Otherwise, the
observations were executed as scheduled, and no further anomalies were
noted.

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

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

   1.24 Completed STIS/CCD/MA2 8043 (Physical Properties of H-I and H-II
Regions)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations of the early-type star HD124314 in order to study its H-I
and H-II regions.  Interstellar absorption lines within the wavelength
intervals 1170-1370A and 1630-1890A in the spectra of 10 early-type stars
are being observed with the highest resolution mode of STIS.  A wavelength
calibration image was also taken.  The observations were executed as
scheduled, and no anomalies were noted.

   1.25 Completed Two Sets of FGS 7484 (The Masses of the O-type Binary 15
Monocerotis)

       The Fine Guidance Sensors (FGSs) was used to make astrometric
observations of O-type class, binary system stars HD47839 and HD38666.
This binary system was recently discovered to be a speckle and
spectroscopic binary with an orbital period of 23.6 years. .  As described
in 2.1 and HSTAR 7096, the acquisition for the first iteration of this
proposal defaulted to fine lock backup on one FGS only.  Otherwise, the
observations were completed as scheduled, and no further problems were
reported.

   1.26 Completed WF/PC-2 6659 (A Search For Superplanets Around Weak T-
Tauri Stars)

       The WF/PC-2 was used to make observations in the 1 micron band of
the T-Tauri class star HBC427 in order to search for superplanets.  Weak
T-Tauri class stars are thought to have dissipated their circumstellar
disks recently, possibly by forming planetary systems.  The observations
were completed as planned, and no anomalies were reported.

   1.27 Completed STIS/CCD/MA1/MA2 7673 (STIS MAMA Sensitivity and Focus
Monitor)

       The Space Telescope Imaging Spectrograph (CCD/MA1/MA2) was used to
make observations of standard star GRW+70D582 in order to perform a MAMA
sensitivity and focus monitoring program.  This is to monitor sensitivity
of each MAMA grating mode to detect any change due to contamination or
other causes.  The observations were executed as scheduled, and no
anomalies were noted.

   1.28 Completed WF/PC-2 7504 (Calibration of Nearby Type Ia Supernovae as
Standard Candles: The Next Three-Year Step)

       The WF/PC-2 was used to make observations of parent galaxy NGC-4527
in order to determining its Cepheid distance.  This is to continue the
calibration of the Type 1a supernova as standard candles.  The observations
were completed as planned, and no porblems were reported.

   1.29 Completed WF/PC-2 6554 (Extragalactic Globular Cluster Systems)

       The WF/PC-2 was used to make observations of a extragalactic
globular cluster system which is located in galaxy NGC-4365.  This is part
of a survey which will cover a range in galaxy luminosity, morphological
type, environment, galactic cluster specific frequency and galactic cluster
mean metallicity.  The observations were executed as scheduled, and no
anomalies were noted.

   1.30 Completed Three Sets of WF/PC-2 6967 (Blue Continuum Snapshots of
3CR Radio - Continued Galaxies)

       The WF/PC-2 was used to make observations of the radio galaxies
3C134.0, 3C21.1 and 3C119.0A.  Radio galaxies are an important class of
extragalactic objects: they represent one of the most energetic
astrophysical phenomena and they may be used as probes of their
environments.  They are unique probes of the early Universe.  The
observations were completed as planned, and no problems were reported.

   1.31 Completed WF/PC-2 6351 (Resolving SDB Binary Systems)

       The WF/PC-2 was used to make high resolution image of the sdB class,
binary system STAR-21511 in order to try and resolve its two individual
stars.  Evidence has accumulated that a large fraction (if not all) of the
sdB class stars are found in binary systems.  The observations were
executed as scheduled, and no anomalies were noted.

   1.32 Completed FGS 7681 (FGS-3 Red Transfer Function Reference Calibration)

       The Fine Guidance Sensor (FGS-3, the astrometer) was used to make
observations of SAO185689 in order to perform a red transfer function
reference calibration  through the pupil, clear and neutral density filters
at the center of the FGS-3 field of view.  The observations were completed
as planned, and no anomalies were reported.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 32
                                        Successful : 32

       Per HSTAR 7093, the acquisition at 100/152113Z defaulted to fine
lock backup on FGS-1 only when the scan step limits were exceeded on FGS-3.
The proposals detailed in 1.20 and 1.22 may have been affected.

       Following the update errors detailed in 2.2 and HSTARs 7094 and
7095, the acquisition at 101/013213Z defaulted to fine lock backup on FGS-3
only.  The proposals described in 1.3. 1.20, and 1.25 may have been
affected.

                          Scheduled Reacquisitions : 13
                                        Successful : 11

       The re-acquisitions at 099/1252Z and at 099/1429Z both failed due to
large error null bias.  Maps at 099/1208Z and at 099/1345Z showd good
attitude.  HSTAR 7092 was written.  The proposal described in 1.7 was
affected.

   2.2 FHST Updates:

                              Scheduled : 62
                             Successful : 59

       The full maneuver updates at 100/234521Z and at 100/234806Z failed
due to tracker #2.  The following acquisition failed to fine lock backup on
one FGS only, and a map taken near that time showed significant errors.
HSTAR 7094 was written.

       The update at 101/010201Z failed.  The error box results indicated
success but no commanded attitude error was generated.  HSTAR 7095 was
written.

   2.3 Operations Notes:

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

       The STIS MCE-2 reset at 099/182653Z while the low voltage was on and
while outside an SAA interval.  The MAMA-2 was recovered at the time of the
next high voltage on commanding, 099/2110Z, via the SMS.  The STIS flight
software error counter was cleared at 099/1847Z per ROP NS-12.

       The STIS MCE-2 reset at 100/111259Z while the low voltage was on and
while inside an SAA interval.  The MAMA-2 was recovered at the time of the
next high voltage on commanding, 100/2137Z, via the SMS.  The STIS flight
software error counter was cleared at 100/1223Z per ROP NS-12.

       A NSSC-1 status buffer dump was performed at 100/1730Z as directed
by ROP NS-3.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH