HUBBLE SPACE TELESCOPE DAILY REPORT #2689 PERIOD COVERED: 0000Z (UTC) 08/17/00 - 0000Z (UTC) 08/18/00 Daily Status Report as of 231/0000Z 1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED: 1.1 Completed Three Sets of WF/PC-2 8826 (Cycle 9 Supplemental Darks pt 1) The WF/PC-2 was used to perform a T dark calibration program that obtains three dark frames every day in order to provide data for monitoring and characterizing the evolution of hot pixels. There were no reported anomalies. 1.2 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. 1.3 Completed STIS/CCD/MA1 8287 (A Search For Transparent Lines of Sight With Intergalactic He-II Absorption Towards 26 Bright z > 2.9 Quasars) The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make He-II absorption line observations of quasar HS1431+314. The aim is to identify more suitable bright objects for detailed studies of intergalactic He-II absorption at a redshift of Z <2.9 and >3.2 . A wavelength calibration observation was also taken. The observations were executed as scheduled, and no anomalies were noted. 1.4 Completed Three 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. 1.5 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. 1.6 Completed STIS/CCD/MA1 8273 (The Oxygen Abundance in Translucent Interstellar Clouds) The Space Telescope Imaging Telescope (CCD and MA1) was used to obtain high-resolution STIS echelle observations of the interstellar O I Lambda1356 absorption toward a sample of stars behind six translucent clouds characterized by large H I column densities and high extinctions. Previous GHRS measurements of this weak feature in diffuse clouds have shown no evidence of density-dependent O depletion from the gas phase and indicate a total {gas + dust} interstellar O abundance that is about 2/3 of the solar value. The observations were completed nominally. 1.7 Completed WF/PC-2 8131 (HST Imaging of Moderate Redshift X-ray Emitting Groups of Galaxies) The WF/PC-2 was used to make observations of the infrared and x-ray emitting galactic cluster Gal-Clus-0723. Most galaxies in the universe, including our own Milky Way, are members of poor groups of galaxies. Recent optical and X- ray observations of nearby groups have revealed considerable new insight into these important systems. The observations were completed as scheduled, and no problems were reported. 1.8 Completed Two Sets of STIS/CCD 8808 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation III) The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal. The observations completed with no anomalous activity. 1.9 Completed WF/PC-2 8609 (Host Galaxy Luminosities of the Most Luminous QSOs) The WF/PC-2 was used to determine the factors that decide whether a galaxy is host to a luminous QSO. Recent evidence indicates that host galaxy spheroid mass is a key factor: we want to test the relationship between host galaxy and QSO luminosity at the highest feasible QSO luminosities by measuring the luminosities and profiles of host galaxies for QSOs with -25.8 > M_V > -27.6. Current data in this area are conflicting. The observations completed with no reported anomalies. 1.10 Completed STIS/CCD 8631 (Bright Quasar Close Lensing Search II) The Space Telescope Imaging Spectrograph (CCD) was used to expand the Cycle 8 second generation HST snapshot survey of bright quasars, optimized to find lenses with component image separations < 1". The observations completed nominally. 1.11 Completed STIS/CCD/MA2 8126 (Observations Of QSO Pairs) The Space Telescope Imaging Spectrograph (CCD and MA2) was used to obtain ultraviolet spectra of four QSO pairs with similar common redshift ranges {z ~ 0.7--1} and projected linear separations gradually increasing from ~0.5 to sim1 h^-1_100 Mpc. This is being done to: {i} to probe the extension and structure of gaseous complexes giving rise to the formation of LyAlpha absorption lines at intermediate redshift {z ~ 0.9}, {ii} to investigate the transversal proximity effect of the foreground quasar along the line of sight to the background quasar; and {iii} study the environment in which QSOs reside and in particular the presence of gas around the foreground quasar. The observations completed nominally. 1.12 Completed STIS/CCD/MA2 8311 (Moderate Redshift Analogs To Lyman-Break Galaxies?) The Space Telescope Imaging Spectrograph (CCD and MA2) was used to determine whether high luminosity galaxies selected using rest ultraviolet luminosity at low-to-moderate redshift {0.2