HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2110

PERIOD COVERED:  0000Z (UTC) 04/24/98 - 0000Z (UTC) 04/27/98

Daily Status Report as of 117/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Seven Sets of WF/PC-2 7712 (WF/PC-2 Cycle 7 Supplemental
Darks pt2/3)

       The WF/PC-2 was used to make a series of Cycle 7 supplemental
calibration darks.  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 executed as scheduled, and no
anomalies were noted.

   1.2 Completed STIS/CCD 7635 (STIS CCD Hot Pixel Annealing)

       The Space Telescope Imaging Spectrograph (CCD) was used to test the
hot pixel annealing procedure.  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 completed as planned, and no problems were reported.

   1.3 Completed Two Sets of NIC/2 7330 (The Fueling of Active Nucleii: A
NICMOS Snapshot Survey)

       The Near Infrared Camera (Camera Two) was used to probe the dark
matter distribution of NGC-5427, NGC-4785 and NGC-5506 far from the center
by observing intervening absorption from the MgII doublet (lambda 2800) in
the spectrum of one background QSO located in a geometrically optimal
position.  HST observations are required because this feature is in a
wavelength range not accessible from the ground, and the QSO magnitudes and
expected strength of absorption make IUE observations unfeasible.  The
proposal completed as expected with no anomalies.

   1.4 Completed Two Sets of STIS/MA1 7401 (A Critical Test of
Crystallization in White Dwarf Stars)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
observations of the white dwarf star BPM37093.  Theoretical calculations
indicate that the massive pulsating DA white dwarf, BPM37093, has a
crystallized ion interior.  A wavelength calibration image was also taken.
During the second iteration of this proposal, the loss of lock mentioned in
2.1 occurred, temporarily taking down the take data flag.  Otherwise, the
observations were executed as scheduled, and no further anomalies were
noted.

   1.5 Completed Nine Sets of WF/PC-2 7909 (POMS Test Proposal: WF II
Parallel Archive Proposal)

       The WF/PC-2 was used to make parallel observations as part of the
POMS test proposal.  This test proposal is designed to simulate scientific
plans.  During the fifth iteration of this proposal, the loss of lock
mentioned in 2.1 occurred, temporarily taking down the take data flag.
Otherwise, the observations were completed as planned, and no further
problems were reported.

   1.6 Completed Nine Sets of NIC/2/3 7907 (NICMOS Pure Parallel Winter 97-98)

       The Near Infrared Camera (Cameras Two and Three) was used to make
pure parallel spectrographic observations of sky regions when another
instrument is prime.  During the sixth iteration of this proposal, the loss
of lock mentioned in 2.1 occurred, temporarily taking down the take data
flag.  Otherwise, the observations were completed as planned, and no
further anomalies were reported.

   1.7 Completed Three Sets of WF/PC-2 7625 (WF/PC-2 Cycle 7 Earth Flats)

       The WF/PC-2 was used to make a series of Earth flat calibration
images.  These flat fields will allow mapping of the OTA illumination
pattern and will be used in conjunction with previous internal and external
flats to generate new pipeline superflats.  The observations were completed
as planned, and no anomalies were reported.

   1.8 Completed NIC/1/2/3 7505 (The Hubble Diagram for Distant Supernovae
Measuring Cosmic Deceleration and Global Curvature)

       The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of Super Nova SN1998F in order to produce a precise
Hubble diagram from measuring cosmic deceleration and global curvature.
HST can make an essential contribution by providing photometry with
substantially higher precision and better temporal coverage than can be
obtained from the ground.  The observations were completed as planned, and
no anomalies were reported.

   1.9 Completed STIS/CCD 7635 (STIS CCD Hot Pixel Annealing)

       The Space Telescope Imaging Spectrograph (CCD) was used to test the
hot pixel annealing procedure.  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 completed as planned, and no problems were reported.

   1.10 Completed Three Sets of STIS/CCD 7926 (CCD Dark and Bias Monitor --
Continued)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
several dark and bias calibration observations.  This is to measure CCD
dark current and bias rates for the two supported amplifier settings {gain
= 1 and gain = 4} in order to gather data for making superdarks and
superbiases.  These observations will also 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.

   1.11 Completed Three Sets of STIS/CCD 7803 (Daily Darks to Update
Acquisition Bad Pixel Table Part III)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
daily dark calibration updates.  These daily darks are intended to identify
hot pixels for update to the acquisition on-board FSW hot pixel table.
Daily hot pixel lists can also be used for science data analysis.  The
observations were completed as planned, and no anomalies were reported.

   1.12 Completed Eight Sets of STIS/CCD 7908 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
calibration observations as part of the POMS Test Proposal.  This was a
STIS non-scripted parallel proposal.  The observations were completed as
planned, and no problems were reported.

   1.13 Completed WF/PC-2/STIS/CCD/NIC/1/2 7307 (The Formation and
Evolution of Rich Star Clusters in the LMC)

       The WF/PC-2, the Space Telescope Imaging Spectrograph (CCD), and the
Near Infrared Camera (Cameras One and Two) were used to make observations
of the rich star cluster NGC-6553 which are located within the Large
Magellanic Cloud in order to study their formation and evolution.  These
observations will help us understand the origin and evolution of rich star
clusters in our own galaxy.  The observations were completed as scheduled,
and no anomalies were reported.

   1.14 Completed NIC/1/2/3 7839 (Colliding Stellar Winds: Near-IR Imaging
of the Protoplanetary Nebula M1--92)

       The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of the protoplanetary nebula M1-92 to study its colliding
stellar winds.  The interaction between a fast post-AGB bipolar outflow and
a slowly expanding, dense AGB envelope is believed to be the dominant
dynamical effect in the evolution of protoplanetary nebulae and the shaping
of planetary nebulae.  The observations were completed as planned, and no
problems were reported.

   1.15 Completed WF/PC-2 6587 (Black Holes and Cores of Early-Type Galaxies)

       The WF/PC-2 was used to make observations of early-type galaxy
NGC-6849 in order to study its nuclear core region and its possible black
hole.  The campaign to find black holes in the centers of galaxies using
HST has so far been highly successful.  The observations were completed as
planned, and no problems were reported.

   1.16 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 HD180093 in order to
study dust formation around the star.  It has been known for 60 years that
the declines of R Coronae Borealis {RCB} 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.

   1.17 Completed STIS/CCD 7928 (STIS Spectroscopic CCD Flatfielding --
Continued)

       The Space Telescope Imaging Spectrograph (CCD) was used to make CCD
flat field calibration images in the STIS spectroscopic mode.  The
calibrations were completed as planned, and no problems were reported.

   1.18 Completed NIC/2 7226 (Search for Massive Jupiters)

       The Near Infrared Camera (Camera Two) was used to make a corographic
search for massive planets around nearby, young main sequence star
HD180445.  Because of the extreme youth of this object, any low-mass brown
dwarf and planetary companions will still be in a higher luminosity phase
and thus easily detectable.  A dark calibration image was also taken.  The
observations were executed as scheduled, and no anomalies were noted.

   1.19 Completed Two Sets of NIC/1 7867 (NICMOS Imaging of the Dusty CfA
Seyfert Nuclei)

       The Near Infrared Camera (Camera One) was used to make observations
of the Seyfert Galaxy MRK461.  These data will allow us to determine if the
Seyfert Type 1/2 dichotomy is best explained by the unified model, the
evolutionary picture, or a combination of both of these scenarios.  As
described in HSTAR 6447 and in 2.1, the acquisition for this proposal
defaulted to fine lock backup on one FGS.  Otherwise, the observations were
executed as scheduled, and no further anomalies were reported.

   1.20 Completed WF/PC-2 7277 (Calibration of the Cepheid P-L Relation
with Observations of the Maser-Host Galaxy NGC)

       The WF/PC-2 was used to make observations of the maser-host galaxy
NGC-4258 to study its Cepheid variable stars.  These data will help refine
the calibration of the Cepheid period-luminosity relationship.  The
observations were completed as scheduled, and no problems were reported.

   1.21 Completed Three Sets of NIC/1/2/3 7891 (The Initial Mass Function
of the Galactic Bulge)

       The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of NGC-6558 to measure the complete galactic bulge
luminosity function.  This offers a unique clue to better understanding the
complete stellar content, and hence the stellar mass-to-light ratio, of
spiral bulges and by extension of ellipticals as well.  The observations
were executed as scheduled, and no anomalies were noted.

   1.22 Completed Three Sets of STIS/CCD 7911 (STIS Galactic Plane Pure
Parallel Program)

       The Space Telescope Imaging Spectrograph (CCD) was used to make low
galactic latitude survey observations in parallel with the prime science
observations.  Short exposures with the 50CCD imaging mode will provide the
wavelength zero-point calibration.  These data will be placed immediately
into the Hubble Data Archive.  The observations were executed as scheduled,
and no anomalies were noted.

   1.23 Completed NIC/2 7228 (Imaging and Polarimetry of YSO'S)

       The Near Infrared Camera (Camera Two) was used to investigate the
young stellar object IRAS16293 with coronagraphic imaging, polarimetry, and
line imaging.  The observations were completed as planned, and no problems
were reported.

   1.24 Completed NIC/1/2 7259 (Polarization mapping of the infrared
emission from the jet in M87)

       The Near Infrared Camera (Cameras One and Two) was used to make
polarization mapping of the infrared emissions of the jet from the nuclear
region of galaxy M-87 (a.k.a., NGC-4486).  This jet is bright at optical
through x-ray wavelengths.  Being the closest such optical jet it is a
prime target for high resolution imaging with the HST.  The observations
were executed as scheduled, and no anomalies were noted.

   1.25 Completed NIC/1 7958 (Polarizers Calibration Augmentation)

       The Near Infrared Camera (Camera One) was used to make observations
of the standard unpolarized point source BD32-3739 to perform a polarizer
calibration augmentation.  Also, the polarization fraction and position
angle of polarization were measured for the standard polarized point source
to determine their absolute accuracy in each polarizer and each camera.
The observations were executed as scheduled with no anomalies.

   1.26 Completed WF/PC-2 7618 (WF/PC-2 Cycle 7 Photometric Monitor UV/OPT STD)

       The WF/PC-2 was used to make observations of the standard star
GRW+70D582 as part of a Cycle 7 photometric monitoring program.  This
ultraviolet spectrophotometric standard star was observed in a variety of
filters and cameras to monitor the photometric stability and quantum
efficiency of WF/PC-2 from the far-ultraviolet to near-infrared.  The
observations were completed as scheduled, and no problems were reported.

   1.27 Completed NIC/1/2/3 7875 (Searching for Old Stellar Populations in
Candidate Proto-Spheroidals)

       The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations searching for old stellar populations in candidate
proto-spheroid SA57-4259.  We have compelling evidence from WF/PC-2 images
that these galaxies have optical colors gradients.  The near-infrared is
necessary, however, to reveal color gradients large enough to separate
young and old stellar populations.  Only NICMOS imaging provides enough
spatial resolution and depth to resolve these gradients.  The observations
were completed as planned, and no problems were reported.

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 28
                                        Successful : 28

       The acquisition at 115/111211Z defaulted to fine lock backup on
FGS-3 only when FGS-1 exceeded the scan step limit.  HSTAR 6447 was
written.  The proposal described in 1.19 may have been affected.

       As documented in HSTAR 6448, FGS-1 and FGS-3 experienced loss of
lock for approximately three minutes and fifty-three seconds at 116/0353Z.
Using the new #44 command, lock was immediately recovered.  The proposals
described in 1.4, 1.5, and 1.6 were affected.

                          Scheduled Reacquisitions : 22
                                        Successful : 22

   2.2 FHST Updates:

                              Scheduled : 55
                             Successful : 55

   2.3 Operations Notes:

       The Battery #3 capacity check test was completed at 114/1443Z.
Using an operations note, the Battery #3 limits were reset following the
test.

       The EDAC error counter was cleared five times.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.
/DMH