HUBBLE SPACE TELESCOPE DAILY REPORT #2314 PERIOD COVERED: 0000Z (UTC) 02/22/99 - 0000Z (UTC) 02/23/99 Daily Status Report as of 054/0000Z 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 7948 (CCD Dark and Bias Monitor -- Cont. to Dec. 98) The Space Telescope Imaging Spectrograph (CCD) was used to measure CCD dark current and bias rates for the two supported amplifier settings {GAIN=1 and GAIN=4} in order to gather data for making superdarks and superbiases. The data will be used 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 6967 (Blue Continuum Snapshots of 3CR Radio - Continued Galaxies) The WF/PC-2 was used to make observations of the radio galaxies 3C136.1 and 3C133.0. 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. 1.4 Completed Six 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. 1.5 Completed WF/PC-2 7500 (The Horizontal Branch of the M31 Dwarf Spheroidal Companion And III) The WF/PC-2 was used to make observations of the M-31 dwarf spheroidal companion Andormeda III in order to study its stars in the horizontal branch of the H-R Diagram. This class of companions show a surprising diversity in the epoch of their major star formation episodes. The observations were executed as scheduled, and no anomalies were noted. 1.6 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. 1.7 Completed Four 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. 1.8 Completed WF/PC-2 7476 (Sakurai's Nova-Like Object: Real-Time Monitoring of a Stellar Thermal Pulse) The WF/PC-2 was used to make images of Sakurai's nova-like object in order to do real-time monitoring of a stellar thermal pulse. The eruption of Sakurai's nova-like variable in Sagittarius presents a "once-in-a-lifetime" opportunity for real-time observations of a star undergoing a final helium thermal pulse. The observations were completed as planned, and no anomalies were reported. 1.9 Completed WF/PC-2 7466 (From Globular Clusters to Tidal Dwarfs: Structure Formation in Tidal Tails.) The WF/PC-2 was used to make observations of the globular clusters (et al.) within the tidal tail of galactic merger NGC-4038. By modeling these systems with N-body hydrodynamic codes, can we identify the physical circumstances and formation histories which can produce tidal dwarfs, star clusters, and other structures in tidal tails. The observations were completed as planned, and no anomalies were reported. 1.10 Completed WF/PC-2/STIS/CCD 7615 (Determination of the Mass Function of a Globular Cluster Through Gravitational Microlensing) The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were used to make gravitational microlensing observations of the large globular cluster NGC-6656 located in Sagittarius in order to study its mass function. Gravitational microlensing offers a unique and direct method of determining the masses of stars and other compact objects down to planetary masses. A bias and a dark calibration observations were also taken. The observations were completed as planned, and no problems were reported. 1.11 Completed WF/PC-2 6355 (A UV Atlas of Nearby Galaxies) The WF/PC-2 was used to make ultraviolet observations of the nearby galaxy NGC-2276. The aim of the project is to build a reference ultraviolet atlas of galaxies whose optical images are well known, with the highest possible degree of information, covering all the morphological types and luminosity classes. The observations were executed as scheduled, and no anomalies were noted. 1.12 Completed STIS/CCD 7269 (The 1997/98 Eclipse of VV Cephei) The Space Telescope Imaging Spectrograph (CCD) was used to make ultraviolet spectrographic observations of the long-period eclipsing binary star HD208816 (a.k.a., VV-Cephei). This eclipse will provide an unprecedented opportunity to obtain spatially resolved information about the density, ionization and velocity structure in the outer atmosphere of the M supergiant primary. A wave length calibration observation was also taken. The observations were completed 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 : 12 Successful : 12 Scheduled Reacquisitions : 4 Successful : 4 2.2 FHST Updates: Scheduled : 26 Successful : 26 2.3 Operations Notes: Using ROP SR-1, the SSR EDAC error counter was cleared three times. A TTR was written for three instances of data hits and missing minor frames: at 054/075340Z (13 minor frames), at 054/075546Z (41 minor frames), and at 054/075607Z (14 minor frames). HST real-time operations remain on the PRS system, However, with all CCS components now in an operational state, it is expected that CCS "A" string will resume real-time operations this morning. The Gyro-3 drift rate bias trend rate of change is now 38.94 arcseconds/hour/day, above the desired limit of 10.8 arcseconds/hour/day. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH