HUBBLE SPACE TELESCOPE

   DAILY REPORT #2861

PERIOD COVERED:  0000Z (UTC) 04/27/01 - 0000Z (UTC) 04/30/01

Daily Status Report as of 120/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Seven Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)

        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 proposal completed nominally.

    1.2 Completed Five Sets of STIS/CCD 8864 (CCD Dark Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks for the CCD.  The proposal completed nominally.

    1.3 Completed WF/PC-2 8820 (Wavelength Stability of Narrow Band and 
Linear Ramp Filters)

        The WF/PC-2 was used to verify the mapping of wavelength as a 
function of CCD position on linear ramp filters and to check for changes in 
central wavelengths of the narrow band filters.  The proposal completed 
nominally.

    1.4 Completed Twelve Sets of STIS/CCD 9248 (Probing the Large Scale 
Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the distortion of light bundles from distant galaxies that probe the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  Its tidal gravitational field distorts the observable image 
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}.  The 
observations completed nominally.

    1.5 Completed STIS/CCD 8591 (The Smallest Nuclear Black Holes)

        The Space Telescope Imaging Spectrograph (CCD) was used to observe 
small nuclear black holes which are the last major unexplored part of BH 
parameter space, searching for the smallest BHs that HST can possibly 
find.  The proposal completed with no reported anomalies.

    1.6 Completed Four Sets of WF/PC-2 8816 (Cycle 9 UV Earthflats)

        The WF/PC-2 was used to obtain sequences of Earth streak flats to 
improve the quality of pipeline flat fields for the WFPC2 UV filter set and 
in order to monitor flat field stability.  There were no reported problems.

    1.7 Completed STIS/CCD 8872 (Spectroscopy of a New Hot spot in SN 1987A)

        The Space Telescope Imaging Spectrograph (CCD) was used to take 
images and diagnostic spectra in the 2900--10250 A range of 
rapidly-evolving hot spots and other shock features in the equatorial ring 
surrounding SN 1987A.  A combination of aperture positions through the low 
and high resolution gratings will provide resolved data on all known and 
any new hot spots in all optical emission lines.  There were no reported 
problems.

    1.8 Completed Twelve Sets of WF/PC-2 9244 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
Archival Pure Parallel program.  The program will be used to take parallel 
images of random areas of the sky, following the recommendations of the 
Parallels Working Group.  The observations completed with no anomalous 
activity.

    1.9 Completed Two Sets of WF/PC-2 8599 (A Census of Nuclear Star 
Clusters in Late-Type Spiral Galaxies)

        The WF/PC-2 was used to conduct an I-band snapshot survey of a 
well-defined sample of nearby, face-on spiral galaxies of type Scd or 
later.  The proposal completed nominally.

    1.10 Completed WF/PC-2 8781 (NGC 2363 V1: A Rare Case Of Major LBV 
Eruption)

        The WF/PC-2 was used to observe NGC 2363 which in January 1966, 
revealed the presence of a new bright, blue star.  It has been shown that 
this star is a Luminous Blue variable {LBV} undergoing a major 
outburst.  The observation completed nominally, with no reported problems.

    1.11 Completed Two Sets of STIS/CCD 8865 (Bias Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used 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 track the evolution of hot 
columns.  The proposal completed with no anomalous activity.

    1.12 Completed WF/PC-2 8677 (Extragalactic Novae: the Maximum Magnitude 
- Rate of Decline Relation in NGC 4472)

        The WF/PC-2 was used to accomplish two goals: {1} to provide the 
first homogeneous observational constraints on theoretical models for novae 
outbursts; and {2} to assess the reliability of novae as standard candles 
by using WFPC2 to collect well sampled light curves for 20-50 novae in the 
supergiant elliptical galaxy NGC 4472, the brightest galaxy within 30 
Mpc.  Both the length of the observing window and the temporal sampling of 
the observations are specifically designed to ensure that the novae peak 
magnitudes and decline rates are measured accurately.  These data will be 
used to construct the first `Maximum Magnitude versus Rate of Decline' 
{MMRD} relation for a galaxy beyond the Local Group.  This relation is not 
only a potentially powerful standard candle, but its shape and dispersion 
are directly linked to physical parameters which govern the physics of 
novae outbursts such as the white dwarf mass, temperature and mass 
accretion rate.  The proposal completed with no reported problems.

    1.13 Completed STIS/CCD/MA2 8594 (H-Deficient Condensations In Pne -- A 
Key To Discrepancies In Abundance Determinations)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
obtain deep long-slit spectra for the well-resolved H-deficient knots of A 
30 and to search for such knots in A30-6.57AR.  The data will yield the 
spatially resolved temperature, density and ionization structure of the 
knots in Abell 30, and, for the first time, accurate ORL C and O abundances 
for them.  The results will lead to a much better understanding of the 
physics of such knots and their effects on abundance determinations 
.  There were no reported problems.

    1.14 Completed STIS/CCD/MA2 8672 (Establishing the Gaseous Phases of 
Galaxies Following the Epoch of Star Formation)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used in 
an ambitious program designed to: {1} establish if high ionization, 
metal-rich halos/coronae were in place as early as z~1, which would imply 
that extended, early-epoch, galactic halos result from reprocessed galactic 
gas and that the kinematics are mechanically driven; {2} obtain the first 
comparison of the relative kinematics of low and high ionization species in 
z~1 galaxies, covering a wide range of N{HI} environments and MgII 
kinematic spreads up to ~400 km/s; {3} discriminate between single-phase 
and multi-phase ionization, and therefore spatial, absorbing structures 
{eg. MgII clouds embedded in diffuse high ionization halos}; and {4} place 
constraints on the gas-phase metallicites in early-epoch galaxies.  The 
observations complete with no reported problems.

    1.15 Completed STIS/CCD/MA1 8643 (Ultraviolet Properties of the Metal 
Rich M87 Globular Cluster System)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
We propose to obtain far-ultraviolet photometry of the metal rich globular 
cluster system of the elliptical galaxy M87.  This system represents a key 
link between the well-understood populations of the clusters and the hot 
stars in elliptical galaxies, where our physical insight is presently 
limited.  The goal is to establish the relationship between cluster metal 
abundance and the production of UV-bright populations of stars on the 
"extreme horizontal branc"' at T{eff} > 16000K.  No anomalies were reported.

    1.16 Completed Three Sets of WF/PC-2 8583 (Imaging Snapshots of Asteroids)

        The WF/PC-2 was used to obtain images of the fifty largest main 
belt asteroids that have favorable apparitions during cycle 9.  The images 
will be searched for companion bodies, as well as mineralogical variegation 
on the resolved main bodies.  There were no reported problems.

    1.17 Completed Two Sets of WF/PC-2 8602 (A Snapshot Survey of the Sites 
of Recent, Nearby Supernovae)

        The WF/PC-2 was used to conduct a snapshot survey in V and I of the 
sites of the nearby SNe, which have precisely known positions, to obtain 
high-resolution information on their local environment.  The proposal 
completed with no reported problems.

    1.18 Completed FGS/1 8731 (A High Angular Resolution Survey of the Most 
Massive Stars in the SMC)

        Fine Guidance Sensor #1 was used to conduct high angular resolution 
observations of some of the SMC's hottest and most luminous objects by 
conducting a comprehensive survey of nearly every spectral type in the 
upper portion of the HR diagram.  Binary or multiple star systems will be 
detected down to an unprecedented level, more than one order of magnitude 
better than possible with WFPC2.  The targets selected include a 
representative list of normal Main Sequence O-stars and their evolved 
descendents, namely supergiants, hypergiants, LBVs, and WRs, many of which 
have been previously observed by HST's spectrometers for purposes of 
cosmological calibrations.  The observations completed, and no problems 
were reported.

    1.19 Completed Two Sets of FGS/1 9240 (Astrometric Mass Determination 
of an Extrasolar Planet Candidate)

        Fine Guidance Sensor-1R was used to perform astrometric 
observations that will allow a quick measure of the sky-plane motion of 55 
Cancri, a G star with an Msin{i} = 0.9 MJ radial velocity companion with a 
14 day period.  By using 7 pairs of visits, where each visit within a pair 
has the same parallax factor, we will be able to accurately determine the 
stars's proper motion.  The reflex motion of the star, due to its orbit 
about the star-companion barycenter, will manifest itself as a systematic 
residual to the measured proper motion if the companion is sufficiently 
massive.  There were no reported problems.

    1.20 Completed STIS/CCD 8607 (Completing the Local AGN Inventory: The 
AGN Content of Composite Nuclei)

        The Space Telescope Imaging Spectrograph (CCD) was used to increase 
the knowledge of the local space density of AGNs which is of fundamental 
importance to a number of astrophysical problems.  A significant fraction 
of nearby galaxies have nuclei whose spectra are intermediate between those 
of LINERs and nuclear starbursts.  These ``transition objects'' may be 
composite systems that contain both a central AGN and circumnuclear star 
formation.  We will test this hypothesis by obtaining spatially-resolved 
optical spectra of a well-defined sample of 15 nearby transition nuclei 
selected from the extensive ground-based survey of Ho, Filippenko, and 
Sargent.  The observations completed with no reported problems.

    1.21 Completed STIS/CCD/MA1 8712 (The Wind Accretion Wake In A Detached 
Binary System)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
observe RW Hya {= HD 117970}, the only known detached binary system, where 
direct observational evidence for wind accretion onto a white dwarf is 
found.  UV
observations will enable the investigator to advance knowledge in a field 
which has for long had to remain a theoretical subject.  RW Hya is an 
eclipsing system containing a mass-losing M-giant and a hot white dwarf on 
circular orbits {370 days}.  The observation completed with no reported 
problems.

    1.22 Completed WF/PC-2/STIS/MA1 8686 (LINERs in Early-type Galaxies: 
Ionized by the UV-upturn Population?)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (MA1) were 
used to investigate the presence of extended ionized gas with LINER spectra 
in a large fraction {60-70%} of early-type galaxies.  The observations 
completed with no reported anomalies.
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The following scheduled proposals were not executed due to the ZGSP entry.
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Two Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)
Two Sets of STIS/CCD 8864 (CCD Dark Monitor-Part 2)
WF/PC-2 8820 (Wavelength Stability of Narrow Band and Linear Ramp Filters)
Ten Sets of STIS/CCD 9248 (Probing the Large Scale Structure: Cosmic Shear 
Observations)
STIS/CCD 8591 (The Smallest Nuclear Black Holes)
WF/PC-2 8816 (Cycle 9 UV Earthflats)
Two Sets of WF/PC-2 9244 (POMS Test Proposal: WFII Parallel Archive 
Proposal Continuation)
Two Sets of WF/PC-2 8599 (A Census of Nuclear Star Clusters in Late-Type 
Spiral Galaxies)
STIS/CCD 8865 (Bias Monitor-Part 2)
WF/PC-2 8677 (Extragalactic Novae: the Maximum Magnitude - Rate of Decline 
Relation in NGC 4472)
STIS/CCD/MA2 8672 (Establishing the Gaseous Phases of Galaxies Following 
the Epoch of Star Formation)
Two Sets of WF/PC-2 8583 (Imaging Snapshots of Asteroids)
FGS/1 8731 (A High Angular Resolution Survey of the Most Massive Stars in 
the SMC)
STIS/MA1 8721 (An UV Imaging Survey of IR-Bright Star- Forming Galaxies)
Three Sets of WF/PC-2 8667 (Nuclear Stellar Disks in Early Galaxies: Black 
Hole Masses and Disk/Bar/Bulge Evolution)
STIS/CCD/MA2 8681 (Snapshot Survey of Variability of Narrow and Broad 
Associated Absorption Lines in Quasars)
STIS/MA1 8572 (Identifying Normal Galaxies at 1.3 < z < 2.5)
STIS/MA1 8862 (FUV-MAMA Cycle 9 Flats)

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 20
Successful: 17

        The acquisitions at 120/0208Z, 120/0352Z, and 120/0624Z failed.
  Scheduled Re-acquisitions:  8
Successful:  7

        The re-acquisition at 120/0755Z failed.

    2.2 FHST Updates:
Scheduled: 55
Successful: 53

    2.3 Operations Notes:

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

        On two occasions the CCS engineering status buffer limits were 
adjusted per ROP DF-18A.

        SSA transmitter #2 was turned on and off for the intervals 
117/142246Z to 117/144453Z and 119/1655Z to 119/1723Z.  SSA transmitter #1 
was turned on and off for the intervals 119/1944Z to 119/2005Z, 120/0053Z 
to 120/0122Z and 120/0244Z to 120/0314Z.  In each case, ROP IC-2 was used.

        The STIS MCE-1 reset at 118/120420Z while the low voltage was on 
and while inside an SAA interval.  Per ROP NS-12, the STIS flight software 
error counter was cleared at 118/1428Z.  MAMA-1 was recovered at 
118/131317Z when the high voltage was turned on via SMA commanding.

        A TTR was written for a required re-transmit of commands during a 
486 load uplink at 118/0927Z.

        HSTAR 8187 was written when an FHST map failed at 118/161908Z.  No 
stars were found in both FHST #2 and FHST #3.

        At 118/201403Z, per HSTAR 8189, the HST entered Zero Gyro Sun Point 
(ZGSP) mode when the gyro #5 motor currents exceeded the motor current 
safemode test limit.  The motor current reached approximately 330 
mAmps.  Gyro #2 was powered on and gyro #5 was powered on at 118/2309Z.  A 
gyro re-configuration was completed by 119/0252Z.  After recovery from ZGSP 
at 119/1300Z and a period of closely monitoring the HST, a Health and 
Safety Load was uplinked and then activated at 119/1331Z.  FOC safe 
recovery (part 1) was completed by 119/1159Z, STIS was recovered to operate 
at 119/1705Z, WF/PC-2 auto-flush was enabled at 119/1710Z, at 119/2121Z 
STIS CCD recovery was completed as was TEC Cool down, STIS MAMAs 1 and 2 
low voltage was enabled at 119/2222Z, and FOC safing recovery (part 2) was 
completed at 119/2225Z.  Normal science operations re-commenced at 
120/0000Z with the intercept of the science SMS.

        The NSSC-1 status buffer was dumped and reset at 119/2138Z, using 
ROP NS-3.

        Per ROP NS-5, SI C&DH errors were reset at 119/2226Z.

        Since normal science began, the gyro biases have been settling out, 
but are still large enough to cause acquisition problems (see 2.1).  These 
failures are more completely documented in HSTAR 8192.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW