HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2353

PERIOD COVERED:  0000Z (UTC) 04/16/99 - 0000Z (UTC) 04/19/99

Daily Status Report as of 109/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Three 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.

   1.2 Completed Two Sets of STIS/CCD/MA1/MA2 8043 (Physical Properties of
H-I and H-II Regions)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used
to make observations of the early-type stars HD103779 and HD88115 in order
to study Their 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.

   1.3 Completed Nine 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.

   1.4 Completed Two Sets of 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.

   1.5 Completed Five 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.

   1.6 Completed Two Sets of WF/PC-2 6461 (High-Resolution Next Bright
Galactic Nova)

       The WF/PC-2 was used to make high resolution images of the bright
galactic nova U-Scorpio after it erupted to search for fluorescence and
reflection light echoes from, and small-scale structure in, the nova
circumstellar gas and dust ejecta.  A wavelength calibration image was also
taken.  The observations were executed as scheduled, and no anomalies were
noted.

   1.7 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.  The observations
were completed as planned, and no anomalies were noted.

   1.8 Completed Two Sets of 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.

   1.9 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 centers of nearby galaxy NGC-3384.  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.

   1.10 Completed WF/PC-2 8059 (POMS Test Proposal: WF-2 Targeted Parallel
Archive Proposal)

       The WF/PC-2 was used to make observations in parallel with the prime
science observations.  The parallel opportunities available with WF/PC-2 in
the neighborhood of bright galaxies are treated in a slightly different way
from the normal pure parallels.  Local group galaxies offer the opportunity
for a closer look at young stellar populations.  The observations were
completed as planned, and no anomalies were reported.

   1.11 Completed 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 galaxy NGC-3414 (taken from a list of 150 galaxies) in order to
study its 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.

   1.12 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+2116+26 and B2+1347+28.  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.

   1.13 Completed STIS/CCD/MA1 7432 (Morphological and Spectral Evolution
of Galaxies)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations to study the morphological and spectral evolution of the
galaxies 3C135-1.  A library of ultraviolet images of normal galaxies at
low redshifts is essential to our understanding of the properties and
evolution of the high redshift universe.  The observations were completed
as planned, and no problems were reported.

   1.14 Completed STIS/CCD/MA1 7477 (Dust Formation Around R Coronae
Borealis Stars: Where is the CO?)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations of the R Coronae Borealis class star V854-Cen in order to
study dust formation around the star.  It has been known for 60 years that
the declines of R Coronae Borealis stars are caused by circumstellar dust
formation.  A wavelength calibration image was also taken.  The
observations were completed as scheduled, and no anomalies were reported.

    1.15 Completed WF/PC-2 7341 (Absolute Proper Motions of Nearby Dwarf
Spheroidal Galaxies)

       The WF/PC-2 was used to measure precise absolute proper motions for
the dwarf spheroidal satellite galaxy CAR-QSO-06 of the Milky Way using
spectroscopically-confirmed background QSOs to define a zero-velocity
reference frame.  The observation completed as planned with no reported
anomalies.

   1.16 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-Pos4 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.

   1.17 Completed WF/PC-2 6159 (Giant H-II Regions in NGC-6822)

       The WF/PC-2 was used to make observations of the H-II regions in
galaxy NGC-3136.  Giant H-II regions in external galaxies represent centers
of young massive star formation and their structure may indicate the
process of progressive star formation.  The observations were completed as
scheduled, and no problems were reported.

   1.18 Completed STIS/CCD/MA2 7402 (Chromospheric Activity in Old Stars:
Halo Subdwarfs' Variability)

       The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
make observations of the old sub-dwarf star HD84937 in order to study its
chromospheric activity.  All normal stars cool enough to have convection
zones share a common minimum level of chromospheric activity which
decreases with advancing spectral type; most show higher emission levels
which vary with time.  A wavelength calibration observation was also taken.
The observations were executed as scheduled, and no anomalies were noted.

   1.19 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 galaxy
3C226.0.  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.

   1.20 Completed WF/PC-2 7390 (High Resolution UV Spectroscopy of the
Extra-Ordinary Central Star of Abell 35)

       The WF/PC-2 was used to make high resolution ultraviolet
observations of the central extra-ordinary star N-BD-22D24 which is located
in the center of planetary nebula  Abell 35.  This star is a rapidly
rotating G8III-IV star which dominates the optical light, and a white
dwarf, probably belonging to the PG1159 class, that dominates the UV flux.
A wavelength calibration image was also taken.  The observations were
completed as scheduled, and no problems were reported.

   1.21 Completed Five 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.

   1.22 Completed Three Sets of WF/PC-2 7790 (WF/PC-2 Narrow-Band Imagery
of the Carina Nebula {NGC-3372})

       The WF/PC-2 was used to make narrow band imagery of the Carina
Nebula (a.k.a., NGC-3372).  The intricate "Keyhole" structure at the center
of the Carina Nebula was imaged in several WF/PC-2 narrow-band filters.
The observations were executed as scheduled, and no anomalies were noted.

   1.23 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.

   1.24 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 cluster (GC) 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.

   1.25 Completed STIS/CCD 7361 (The Nature of Nuclear Activity in Nearby
Galaxies)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of the nuclear region of galaxies N4203 and N4245.  The high
resolution spectra will be used to search for broad components in H-Alpha
and for velocity gradients, indicative of gas rotation or other ordered
motions.  A wavelength calibration image was also taken.  The observations
were executed as scheduled, and no anomalies were noted.

   1.26 Completed WF/PC-2 6619 (High Resolution Images of QSO Lyman Alpha
Absorbing Galaxies)

       The WF/PC-2 was used to make several images of galaxy field (Field
1301) in order to obtain high resolution observations of the Lyman Alpha
absorbing galaxies within this field-of-view.  The purpose is to directly
identify the objects responsible for low and intermediate redshift QSO
Lyman-Alpha systems.  The observations were executed as scheduled, and no
anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 24
                                        Successful : 24

                          Scheduled Reacquisitions : 23
                                        Successful : 23

   2.2 FHST Updates:

                              Scheduled : 58
                             Successful : 58

   2.3 Operations Notes:

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

       SI C&DH errors were reset twice per ROP NS-5.

       The CCS configuration monitors were recycled at 107/0738Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH