HUBBLE SPACE TELESCOPE DAILY REPORT #1943 PERIOD COVERED: 0000Z (UTC) 08/15/97 - 0000Z (UTC) 08/18/97 Daily Status Report as of 230/0000Z 1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED: 1.1 Completed Seven Sets of WF/PC-2 7621 (WF/PC-2 Cycle 7 Supplemental Darks PT1/3) The WF/PC-2 was used to make supplemental dark calibration images. This set of calibrations is intended to obtain 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 Three Sets of STIS/CCD 7659 (Daily Darks to Update Acquisition Bad Pixel Table) The Space Telescope Imaging Spectrograph (CCD) was used to make dark calibration images in order to update the acquisition bad pixel table. Daily hot pixel lists can also be used for science data analysis. The observations were executed as scheduled, and no anomalies were noted. 1.3 Completed Three Sets of NIC/2 7495 (Survey of Gravitational Lenses as Cosmological Tools) The Near Infrared Camera (Camera Two) was used to make survey observations of objects MG1549+304, UM673 and Q1634+267 by obtaining deep, high-resolution images in the optical and near IR in order to see if they are gravitational lenses and could be used as a cosmological tool. The observations were executed as scheduled, and no anomalies were noted. 1.4 Completed Four Sets of NIC/2 7331 (Near-IR Properties of the Bulges of Spiral Galaxies) The Near Infrared Camera (Camera Two) was used to make infrared observations of the bulge in spiral galaxies NGC-7217, ESO0404G3, IC4390 and ESO443G80. Near-IR data at HST resolution are essential for correcting for the effect of dust and will enable us to derive robust nuclear properties for the sample. The observations were executed as scheduled, and no anomalies were noted. 1.5 Completed Four Sets of NIC/2 7420 (A Near-Infrared Search for Very Low Mass Companions to Stars Within 10 Parsecs of the Sun) The Near Infrared Camera (Camera Two) was used to make searching observations for very low mass companions to variable stars LHS3262, LHS476, HD42581 and LHS455. These stars are known to be within 10 parsecs of the Sun. The observations were executed as scheduled, and no anomalies were noted. 1.6 Completed Two Sets of WF/PC-2 6431 (Determination of the Extragalactric Distance Scale) The WF/PC-2 was used to make observations of the galaxies NGC-1326 and NGC-1425 to be used in measuring the periods of Cepheid variable stars within these galaxies. This will allow for a more accurate estimate of the distances to these galaxies through the period-luminosity relation for the Cepheid stars. The observations were executed as scheduled, and no anomalies were noted. 1.7 Completed Ten Sets of NIC/1/2/3 7726 (NICMOS One Orbit Parallel) The Near Infrared Camera (Cameras One, Two and Three) was used to make a one orbit parallel calibration observations. The observations were executed as scheduled, and no anomalies were noted. 1.8 Completed Eleven Sets of STIS/CCD 7781 (STIS Non-Scripted Parallel Archive Proposal - Full Orbit) The Space Telescope Imaging Spectrograph (CCD) was used for a non-scripted parallel archive proposal (one full orbit). No details were given. The observations were executed as scheduled, and no anomalies were noted. 1.9 Completed WF/PC-2 7209 (Hubble Deep Field South) The WF/PC-2 was used to make a Hubble Deep Field South observation near the star HD22468. The propose of the deep imaging with the HST Wide Field Camera 2 is to study the high-redshift distribution of galaxies in a Southern field. The observations were completed as planned, and no anomalies were reported . 1.10 Completed NIC/2 7457 (Warm Molecular Hydrogen in Cluster Cooling Flow Nebulae) The Near Infrared Camera (Camera Two) was used to make observations of the emission-line nebula NGC-1275 in order to study warm molecular Hydrogen in a cluster cooling flow nebula. The intracluster gas at the centers of many clusters of galaxies can cool within a Hubble time, prompting the suggestion that the ICM in these clusters cools and flows towards the center, where it subsequently condenses. The observations were completed as planned, and no anomalies were reported. 1.11 Completed NIC/1/2/3 7448 (Star Formation in a Protogalaxy Candidate at z=2.72) The Near Infrared Camera (Cameras One, Two and Three) was used to make observations of the star formation region within the protogalaxy candidate MS1512+36 which is located at a redshift of Z = 2.72 . Recently a new population of galaxies at high redshift has been identified by ultraviolet absorption lines which most likely arise from very young stellar populations. The observations were completed as planned, and no anomalies were reported. 1.12 Completed WF/PC-2 5905 (The Stellar Halo Metallicity Distribution of the Giant Elliptical NGC 5128) The WF/PC-2 was used to study the stellar halo metallicity distribution around the giant elliptical galaxy NGC-5128. These data will allow us to determine accurately for the first time the mean metallicity and metallicity range of the oldest and most metal-poor field stars in a large elliptical galaxy, and thus constrain the level of enrichment which occurred during the earliest star formation. The observations were completed as scheduled, and no problems were reported. 1.13 Completed Fourteen Sets of STIS/CCD 7782 (STIS Non-Scripted Parallel Archive Proposal - Half Orbit) The Space Telescope Imaging Spectrograph (CCD) was used for a non-scripted parallel archive proposal (one-half orbit). The observations were executed as scheduled, and no anomalies were noted. 1.14 Completed NIC/2/3 7424 (NICMOS Imaging of QSO Absorption-- Selected Galaxies at z > 1) The Near-Infrared Camera (Cameras Two and Three) was used to make observations of QSO/galaxy Q0256-000. The images will also be used to connect the absorption line properties to the galaxy morphological properties, inclination angles, and orientations in order to continue to explore the connection between the absorbing gas and the galaxies. The observations were completed as scheduled, and no anomalies were reported. 1.15 Completed WF/PC-2 6943 (WF/PC-2 Cycle 6: Throughput Verification for Narrow Band Filters) The WF/PC-2 was used to make observations of object NGC-6543 in order verify the throughput for the narrow band filters. This program will provide direct verification of throughput of narrow band filters through observations of emission line objects. The observations were completed as planned, and no anomalies were reported. 1.16 Completed Ten Sets of NIC/1/2/3 7729 (NICMOS Short One Orbit Parallel) The Near Infrared Camera (Cameras One, Two, and Three) was used to obtain "JHK" imaging of sky regions while another instrument was prime. These observations were part of the short NICMOS one-orbit parallel program. The observations were executed as scheduled, and no anomalies were noted. 1.17 Completed NIC/1/2/3 7260 (NICMOS Observations of PKS1413+135) The Near Infrared Camera (Cameras One, Two and Three) was used to make observations of PKS1413+13 and to make some offset observations. In deep ground based CCD observations have discovered that there is a BL Lacertae object (PKS1413+135) which apparently lies in a disc host galaxy. The observations were executed as scheduled, and no anomalies were noted. 1.18 Completed WF/PC-2 5779 (X-Ray Star, Supernova Remnant, Bipolar Nebula, Pulsar, POLARIMETRY, PHOTOMETRY) The WF/PC-2 was used to make high spatial and signal-to-noise imaging observations of NGC-6995 to better understand the morphology and motions in this unusual object. The observations were completed as planned, and no anomalies were reported. 1.19 Completed Two Sets of NIC/1/2/3 7701 (NICMOS Short One Orbit Parallel) The Near Infrared Camera (Cameras One, Two and Three) was used as part of a short NICMOS one-orbit parallel program, to obtain "JHK" imaging of sky regions when another instrument is prime. The observations were completed as scheduled, and no anomalies were reported. 1.20 Completed Two Sets of STIS/CCD 7783 (STIS) The Space Telescope Imaging Spectrograph (CCD) was used to make observations taken in parallel with the prime science. The target were listed as an unknown target. The observations were completed , and no problems were reported. 1.21 Completed NIC/1 7255 (NICMOS Observations of JVAS/CLASS Gravitational Lenses) The Near Infrared Camera (Camera One) was used to make observations of the JVAS class, gravitational lens, quasi-stellar source QSO-0221+3. The JVAS/CLASS radio survey has been the most successful to date at finding arcsecond-scale gravitational lenses, almost doubling the known number (11 lenses found of which 10 are new discoveries). The observations were executed as scheduled, and no anomalies were noted. 1.22 Completed NIC/1 7344 (Witnessing the Birth of Radio Galaxies: WF/PC-2 & NICMOS Observations of CSOs) The Near Infrared Camera (Camera One) was used to make observational images of the cores of bright, nearby galaxy (Compact Symmetric Objects) CSO 1943+70 in order to try to witness the birth of a radio galaxy. Only HST can image these galaxies at the same size scale of the CSO itself, also allowing us to search for nuclear structures aligned with the radio source in this formative stage. The observations were completed as planned, and no anomalies were reported. 2.0 FLIGHT OPERATIONS SUMMARY: 2.1 Guide Star Acquisitions: Scheduled Acquisitions : 25 Successful : 25 Scheduled Reacquisitions : 26 Successful : 26 2.2 FHST Updates: Scheduled : 37 Successful : 37 2.3 Operations Notes: Since SM-2 there have been three occurrences where the batteries have not reached charge cut-off during an orbit. If charge cut-off is not reached after three consecutive orbits, the ROC trickle charge elapsed timer will expire and software safemode will be entered. In order to reduce the potential for battery rundown and SWSP safemode entry, solar array slew minimization in SMS230 has been disabled which will significantly reduce the time and number of periods of large sun/solar array incidence angles. A large incidence angle was one of the major factors in not reaching charge cut-off in these battery rundown situations. In subsequent SMSs the maximum solar array offset angle will be set to 25 degrees (previously set to 30 degrees) with slew minimization enabled. The new offset angle will reduce the frequency of large incidence angles, thus reducing the risk of safemode entry due to this type of battery rundown. Real-time operations transitioned to PDB 52.B at 228/0731Z. When no problems were detected, PASSOPS also began using the new database at 228/1330Z. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH