HUBBLE SPACE TELESCOPE DAILY REPORT #2347 PERIOD COVERED: 0000Z (UTC) 04/08/99 - 0000Z (UTC) 04/09/99 Daily Status Report as of 099/0000Z 1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED: 1.1 Completed Two 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 Three 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/STIS/CCD 7496 (Star Formation Histories of Dwarf Irregular Galaxies II: the Old Populations of IC 1613 and Sextans A) The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were used to make observations of the dwarf irregular galaxy DD075. Recent results from the ground and from HST for different types of dwarf galaxies show that even in these apparently simple stellar systems, a variety of different star formation histories can be found. The observations were executed as scheduled, and no anomalies were noted. 1.4 Completed WF/PC-2 7622 (WF/PC-2 Cycle 7 Internal Monitor) The WF/PC-2 was used to make a set of Cycle 7 internal monitoring calibration measurements. A variety of internal exposures are obtained in order to provide a monitor of the integrity of the CCD camera electronics in both bays {gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a monitor for possible buildup of contaminants on the CCD windows. A bias calibration and an internal flat calibration image were also taken. The observations were executed as scheduled, and no anomalies were noted. 1.5 Completed 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 WF/PC-2 6967 (Blue Continuum Snapshots of 3CR Radio - Continued Galaxies) The WF/PC-2 was used to make observations of the radio galaxies 3C175.1 and 3C181.0. Radio galaxies are an important class of extragalactic objects: they represent one of the most energetic astrophysical phenomena and they may be used as probes of their environments. They are unique probes of the early Universe. The observations were completed as planned, and no problems were reported. 1.7 Completed STIS/CCD 8081 (STIS CCD Hot Pixel Annealing II) [2- The Space Telescope Imaging Spectrograph (CCD) was used to make a dark and a bias calibration observation. The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects. The observations were executed as scheduled, and no anomalies were noted. 1.8 Completed WF/PC-2 8399 (Hubble Heritage observations of NGC 4650A) The WF/PC-2 was used to make observations of NGC-4650 as part of the Hubble Heritage observations. This object is a classic example of a polar ring galaxy in which an outer disk orbits in approximately the polar plane of an inner, high surface brightness S0 galaxy. Polar ring galaxies are astrophysically important as highly visible examples of the effects of interactions and/or gas capture in galaxy evolution. The observations were executed as scheduled, and no anomalies were noted. 1.9 Completed Two 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/CCD 8393 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation IV) The Space Telescope Imaging Spectrograph (CCD) was used to make POMS, non-scripted, low galactic latitude observations made in parallel with the prime science observations. The observations were executed as scheduled, and no anomalies were noted. 1.11 Completed WF/PC-2 6790 (Mass Determination of QSOs Using Gravitational Lensing) The WF/PC-2 was used to make observations of quasar Q1148+0055 as part of a program to measure the mass of quasar using the gravitational lensing effect. Only four pairs of quasars with different redshifts and angular separations smaller than 5'' are presently known. The observations were completed as planned, and no problems were reported. 1.12 Completed STIS/CCD 8055 (Long Slit Spectroscopy of the Seyfert Galaxies) The Space Telescope Imaging Spectrograph (CCD) was used to make long slit spectrographic observations of the Seyfert galaxy IRAS11058. These observations are particularly important to detect and measure the mass concentration associated with any central massive black hole. A wave length calibrationThe observations were executed as scheduled, and no anomalies were noted. 1.13 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. 2.0 FLIGHT OPERATIONS SUMMARY 2.1 Guide Star Acquisitions: Scheduled Acquisitions : 5 Successful : 5 Scheduled Reacquisitions : 10 Successful : 10 2.2 FHST Updates: Scheduled : 12 Successful : 12 2.3 Operations Notes: There were no significant problems or event to report. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH