HUBBLE SPACE TELESCOPE

   DAILY REPORT #2606

PERIOD COVERED:  0000Z (UTC) 04/19/00 - 0000Z (UTC) 04/20/00

Daily Status Report as of 111/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Two Sets of STIS/CCD 8437 (Dark Monitor-Part 2 C8)

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

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

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
observations of HCLQ1456-1 and HCLQ1200-2 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.

    1.3 Completed STIS/CCD 8439 (Bias Monitor-Part 2 C8)

        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 reported problems.

    1.4 Completed FGS 8464 (Monitor the Long-Term Stability of FGS1R in 
Position Mode)

        The Fine Guidance Sensors were used to make astrometric 
observations of the star OF957 (and several other reference stars) in order 
to monitor the long-term stability of FGS-1R in the Position Mode.  The 
goal of these measurements is to monitor the internal positional stability 
of the FGSs by measuring many stars in the M-35 check field repeatedly over 
a one year period.  The observations were completed as planned and no 
anomalies were reported.

    1.5 Completed STIS/MA1 8295 (Anomalously Blue Giants: Possible 
Precursurs to Subdwarf B Stars)

The Space Telescope Imaging Spectrograph (MA1) was used to make 
observations of the galaxy NGC-188-003.  Confirmation of the presence of 
hot companions would lend strong support to the theory that the anomalous 
giants are the binary precursors to the sdB class of stars.  The 
observations were completed as planned, and no problems were reported.

    1.6 Completed Two Sets of WF/PC-2 8805 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
WFPC2 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.  The proposal completed with no reported problems.

    1.7 Completed Three Sets of STIS/MA1 8426 (Cycle 8 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) was used to make a 
routine Cycle-8 MAMA dark noise calibration measurement.  This proposal 
will provide the primary means of checking on the health of the MAMA 
detectors.  This is done through frequent monitoring of the background 
count rate.  The observations were completed as planned, and no problems 
were reported.

    1.8 Completed Two Sets of WF/PC-2 8449 (Cycle 8 UV Flats Internal Monitor)

        The WF/PC-2 was used to monitor the stability of the UV flat 
field.  The proposal completed with no reported problems.

    1.9 Completed STIS/CCD 8189 (The Source of Gamma Ray Bursts and the 
Nature of their Hosts)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
high resolution optical and ultraviolet observations of the Gamma Ray 
Burster (GRB) 000301 and its host galaxy.  This comprehensive set of 
observations will provide new insights into the astrophysics of GRBs and 
their high redshift host galaxies.  The observations were completed as 
planned, and no problems were reported.

    1.10 Completed Two Sets of WF/PC-2 8459 (Decontaminations and 
Associated Observations Pt. 2/2)

        The WF/PC-2 was used to perform the monthly decons.  Also included 
are instrument monitors tied to decons: photometric stability check, focus 
monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, 
and UV throughput checks.  The observations were completed nominally.

    1.11 Completed Three Sets of WF/PC-2 8460 (Cycle 8 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 observations completed with no reported problems.

    1.12 Completed WF/PC-2 8146 (A Search for Binary L-Dwarfs)

        The WF/PC-2 was used to search for close binaries amongst the 
sample of 37 low-temperature L dwarfs, identified primarily in the course 
of the DENIS and 2MASS near-infrared surveys.  The observations completed 
with no reported problems.

    1.13 Completed Four Sets of STIS/CCD 8549 (POMS Test Proposal: 
Non-Scripted Parallel Proposal Continuation I)

        The Space Telescope Imaging Spectrograph (CCD) was used to make low 
galactic latitude, non-scripted parallel observations as part of a POMS 
test proposal.  The observations were completed as planned, and no 
anomalies were reported.

    1.14 Completed WF/PC-2 8322 (The Distance to NGC 2841: Improving the TF 
Calibration and Definitively Testing MOND)

        The WF/PC-2 was used to measure a distance to the spiral galaxy NGC 
2841 using Cepheid variables.  NGC 2841 provides a unique opportunity to 
simultaneously probe three separate phenomenon in extragalactic astronomy: 
1} It will provide the highest rotational velocity data point for the 
Cepheid based calibration of the I-band Tully-Fisher relation and thus will 
firmly determine if this relation experiences curvature or remains linear 
all the way out to high rotational velocities. 2} It has hosted two SN Ia 
events; both of which have good photometry {1957A and 1972R}- this 
significantly adds to the number of calibrators for the SN Ia distance 
scale; 3} If its distance can be shown to be significantly less than 19.5 
MPC, then MOND can be definitively ruled out because NGC 2841 will require 
a value of a_o substantially in excess of the empirically determined 
"universal" value.   The observations completed nominally.

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

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

    1.16 Completed WF/PC-2 8100 (Calibration of Nearby Type Ia Supernovae 
as Standard Candles: The Next Step)

        The WF/PC-2 was used to continue the calibration experiment for M{ 
max} of type Ia supernovae {SNe Ia} by determining Cepheid distances to 
their parent galaxies.  The proposal completed nominally.

    1.17 Completed STIS/CCD 8796 (POMS Test Proposal: STIS Non-Scripted 
Parallel Proposal Continuation IV)

        The Space Telescope Imaging Spectrograph (CCD) was used in the 
parallel mode to make some low galactic latitude archive observations.  The 
observations were executed as scheduled, and no anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 10
Successful: 10

  Scheduled Re-acquisitions:  7
Successful:  7

    2.2 FHST Updates:
Scheduled: 21
Successful: 21

    2.3 Operations Notes:

        HST operations continue to be performed from the Building 23 
back-up facility.

        Using ROP DF-1A, eleven 486 tables were dumped at 110/2312Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW