HUBBLE SPACE TELESCOPE DAILY REPORT #2339 PERIOD COVERED: 0000Z (UTC) 03/29/99 - 0000Z (UTC) 03/30/99 Daily Status Report as of 089/0000Z 1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED: 1.1 Completed Three Sets of WF/PC-2 7713 (WF/P-2 Cycle 7 Supplemental Darks pt3/3) The WF/PC-2 was used to make supplemental dark calibration images. 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 completed as planned, and no anomalies were noted. 1.2 Completed Two Sets of STIS/CCD 7949 (CCD Dark and Bias Monitor -- Cont. to June 99) The Space Telescope Imaging Spectrograph (CCD) was used to conduct a CCD dark calibration and a bias monitoring program. It was also scheduled to 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. 1.3 Completed WF/PC-2 6813 (The Oldest Star Clusters of Local Group Irregular Galaxies) The WF/PC-2 was used to make observations of the oldest star cluster NGC-6822-ST located in the irregular galaxies of the Local Group Galactic Cluster. Globular clusters of spiral and elliptical galaxies are well- studied and they have provided much information on the early histories of these types of galaxies. For irregular galaxies, however, very little is known about the globular clusters and other old clusters. The observations were executed as scheduled, and no anomalies were noted. 1.4 Completed Two Sets of STIS/CCD 7912 (STIS Parallel Archive Proposal - Nearby Galaxies - Imaging and Spectroscopy) The Space Telescope Imaging Spectrograph (CCD) was used to make parallel observations of nearby galaxies. This survey will be useful to study the star formation histories, chemical evolution, and distances to these galaxies. These data will be placed immediately into the Hubble Data Archive. The observations were completed as scheduled, and no problems were reported. 1.5 Completed Two Sets of WF/PC-2 8053 (WF/PC-2 Cycle-7 Earth Flats -- Part II) The WF/PC-2 was used to take Earth flat calibration images. This proposal obtains sequences of Earth streak flats to construct high quality flat fields for the WF/PC-2 filter set. The observations were executed as scheduled, and no anomalies were noted. 1.6 Completed Five Sets of WF/PC-2 7620 (WF/PC-2 Cycle 7 Standard Darks) The WF/PC-2 was used to make a series of Cycle 7 standard dark calibration images. This dark calibration program obtains dark frames every week in order to provide data for the ongoing calibration of the CCD dark current rate, and to monitor and characterize the evolution of hot pixels. The observations were executed as scheduled, and no anomalies were noted. 1.7 Completed Two Sets of STIS/MA1 7950 (Cycle 7 MAMA Dark Measurements) The Space Telescope Imaging Spectrograph (MA1) was used to make a dark calibration image. This is to establish if the detectors are performing nominally, that no internal movement of the MCP has taken place, and establish dark level in orbit for a given operating temperature. These darks will be used in later image reduction and also trended over instrument life time as indicators of detector degradation or damage. The observations were completed as planned, and no problems were reported. 1.8 Completed WF/PC-2 6356 (SNAPSHOT Survey of Ultraluminous Infrared Galaxies) The WF/PC-2 was used to make observations of galaxy Gal-200342 as part of a survey of ultraluminous infrared galaxies. The nature of ultraluminous infrared galaxies has generated considerable controversy. The two main issues are: {1} are they powered by violent bursts of star formation or by hidden quasars? {2} are interactions and mergers invariably involved? The observations were executed as scheduled, and no anomalies were noted. 1.9 Completed Five Sets of STIS/CCD 8091 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation) The Space Telescope Imaging Spectrograph (CCD) was used to make high galactic latitude, non-scripted, parallel observations. The observations were completed as planned, and no anomalies were noted. 1.10 Completed STIS/MA1 7345 (Origin and Physical Conditions in the Local Lyman-Alpha Forest) The Space Telescope Imaging Spectrograph (MA1) was used to make observations of PKS2005-48 in order to study the origin and physical conditions in the local Lyman-Alpha forest. A wavelength calibration image was also taken. The observations were executed as scheduled, and no anomalies were noted. 1.11 Completed WF/PC-2 8090 (POMS Test Proposal: WF-II Parallel Archive Proposal Continuation) The WF/PC-2 was used in the parallel mode to make some low galactic latitude archive observations. The program will be used to take parallel images of random areas of the sky. The observations were executed as scheduled, and no anomalies were noted. 1.12 Completed WF/PC-2 7266 (High-Resolution IR and Optical Imaging of the Fields Around a Large Sample of Z > 4.5 Quasars) The WF/PC-2 was used to make observations of the quasar GB1428+421 in order to make high-resolution infrared and optical imaging of the fields around the quasars. This object appears to be very primitive and may represent early stages in the galaxy formation process. The observations were completed as planned, and no anomalies were reported. 1.13 Completed WF/PC-2 6480 (The Butcher-Oemler Effect: Where Have All The Spirals Gone?) The WF/PC-2 was used to make observations of the blue disk-type galaxy A851-POS5 in order to study the Butcher-Oemler effect. Other observational data show that mergers and tidal interactions were apparently more common in younger clusters; these may contribute to the disappearance of spiral galaxies by the present epoch. The observations were executed as scheduled, and no anomalies were noted. 1.14 Completed WF/PC-2 6351 (Resolving SDB Binary Systems) The WF/PC-2 was used to make high resolution image of the sdB class, binary system STAR-07542 in order to try and resolve its two individual stars. Evidence has accumulated that a large fraction (if not all) of the sdB class stars are found in binary systems. The observations were executed as scheduled, and no anomalies were noted. 2.0 FLIGHT OPERATIONS SUMMARY 2.1 Guide Star Acquisitions: Scheduled Acquisitions : 6 Successful : 6 Scheduled Reacquisitions : 10 Successful : 10 2.2 FHST Updates: Scheduled : 15 Successful : 15 2.3 Operations Notes: The SSR EDAC error counter was cleared once per ROP SR-1. The Gyro-3 drift rate bias slope for the last seven day interval is -13.85 arcseconds/hour/day (was -22.91). The slope for the last two day interval is -14.49 arcseconds/hour/day. These slopes continue to exceed the trend limit of +/_ 10.8 arcseconds/hour/day required for re-installation of Gyro-3 into the control loop. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH