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Daily 3623
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3623 PERIOD COVERED: DOYs 149-152 OBSERVATIONS SCHEDULED ACS/HRC 9974 Mid-Ultraviolet Spectral Templates for Old Stellar Systems We propose a three-year program to provide both observational and theoretical mid-ultraviolet {2300A -- 3100A} spectral templates for interpreting the age and metallicity of globular clusters and elliptical galaxies from spectra of their integrated light. The mid-UV is the region most directly influenced by stellar age, and is observed directly in optical and infrared studies of high-redshift quiescent systems. The reliability of age and metallicity determinations remains questionable until non-solar metallicities and abundance ratios are considered, and stars spanning the color-magnitude diagram are included, as we propose here. With archival HST STIS spectra we have improved the list of mid-UV atomic line parameters, then calculated spectra from first principles which match observed spectra of standard stars up to one- fourth solar metallicity. We will extend both observations and calculations to stars of solar metallicity and beyond, and to those in short-lived stages hotter than the main-sequence turnoff, stars not currently well-represented in empirical libraries. The necessary line-list improvements will come from new high-resolution mid-UV spectra of nine field stars. A key application of the results of this program will be to the old systems now being discovered as `Extremely Red Objects' at high redshifts. Reliable age-dating of these places constraints on the epoch when large structures first formed in the universe. STIS/CCD 9966 Physical Parameters of the Erupting Luminous Blue Variable NGC 2363-V1 In 1996, we reported the discovery of a bright variable star in the giant extragalactic H , ii region NGC 2363. Subsequent photometry and high quality HST/STIS spectroscopy of this star, NGC 2363-V1, revealed that we are witnessing a significant event in the evolution of a massive star, namely a major eruption of a Luminous Blue Variable {LBV}. A quantitative analysis of the STIS datasets gathered in 1997 and 1999 allowed us to determine the luminosity, mass loss rate, wind terminal velocity, surface temperature and even Fe content of this erupting LBV. Because such events are rare, continuous monitoring of the physical parameters of NGC 2363- V1 over the course of its present eruption will provide an invaluable set of constraints for theoretical models. We therefore propose to obtain high quality STIS spectra of this star once a year for the next three observing Cycles. FGS 9883 Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster Distances and the Ages of the Oldest Stars The ages of the oldest stars are a key constraint on the evolution of our Galaxy, the history of star formation, and cosmological models. These ages are usually determined from globular clusters. However, it is alternatively possible to determine ages of extreme Population II subgiants in the solar neighborhood based on trigonometric parallaxes, without any recourse to clusters. This approach completely avoids the vexing issues of cluster distances, reddenings, and chemical compositions. There are 3 known nearby, extremely metal-deficient Pop II subgiants with Hipparcos parallax errors of 6-11% which are available for such age determinations. At present, based on the latest isochrones, the derived ages of these stars {HD 84937, HD 132475, and HD 140283} are all close to 14 Gyr, uncomfortably close to or higher than current estimates of the age of the universe. However, the errors in the Hipparcos parallaxes imply uncertainties of at least 2 Gyr in the ages of the 3 stars. We propose to measure parallaxes of these three Pop II subgiants using HST's Fine Guidance Sensor 1R. We expect to reduce the Hipparcos parallax error bars by factors of 5-6, providing the most stringent test yet of current theoretical stellar models of Pop II stars and pushing the age uncertainties to below 0.5 Gyr. These data will also provide a major new constraint on the distance scale of globular clusters, with wide implications for stellar evolution and the calibration of Pop II standard candles. STIS/CCD/MA1/MA2 9871 AALs in Quasars: Diagnostics of the Environment Associated absorption lines {AALs} in quasar spectra carry a wealth of information on the gas-phase kinematics, ionization states, column densities, outflow masses, and elemental abundances near the quasars. Most of the existing UV spectra have low spectral resolution, which hampers efforts to accurately determine these properties at low redshifts. We propose medium-resolution FUV and NUV STIS spectroscopy, more than an order of magnitude improvement in spectral resolution over previous studies, to observe a sample of AAL quasars at redshifts and luminosities intermediate between the nearby Seyferts and the bright, high-z quasars. Our aim is to determine basic physical parameters for the absorbers, measure the abundances, search for AAL variability, and constrain the location of the absorbers relative to the central quasars. A unique aspect of our z~0.2 sample is the ability to get both UV and X-ray diagnostics, thus allowing us to perform a joint analysis of our STIS data with X-ray observations to further constrain the full range of ionizations and column densities of the UV/X-ray absorbing gas. NIC/NIC3 9865 The NICMOS Parallel Observing Program We propose to continue managing the NICMOS pure parallel program. Based on our experience, we are well prepared to make optimal use of the parallel opportunities. The improved sensitivity and efficiency of our observations will substantially increase the number of line-emitting galaxies detected. As our previous work has demonstrated, the most frequently detected line is Halpha at 0.7z1.9, which provides an excellent measure of current star formation rate. We will also detect star-forming and active galaxies in other redshift ranges using other emission lines. The grism observations will produce by far the best available Halpha luminosity functions over the crucial--but poorly observed--redshift range where galaxies appear to have assembled most of their stellar mass. This key process of galaxy evolution needs to be studied with IR data; we found that observations at shorter wavelengths appear to have missed a large fraction of the star-formation in galaxies, due to dust reddening. We will also obtain deep F110W and F160W images, to examine the space densities and morphologies of faint red galaxies. In addition to carrying out the public parallels, we will make the fully reduced and calibrated images and spectra available on-line, with some ground-based data for the deepest parallel fields included. STIS/CCD/MA1 9858 A Search for the Missing Baryons in Nearby Cosmic Filaments Most of the baryons in the local universe are "missing" in that they are not in galaxies or in the previously detected gaseous phases. These missing baryons are predicted to be in a warm-hot low density phase, largely in the giant cosmic filaments that connect the denser virialized clusters and groups of galaxies. Models show that the highest covering fraction of such filaments occurs in superclusters and observations of two AGNs behind known superclusters showed multiple LyAlpha absorption systems at the supercluster redshift. These results are impressive considering that these AGNs were not even optimally located. Here we selected a several AGNs that lie close to the expected central axis of supercluster filaments. These HST observations will identify LyAlpha absorbing gas while a complementary FUSE program will search for OVI gas in the same systems. STIS/CCD 9854 Anomalous Flux Ratios in Quadruple Gravitationally Lensed QSOs We propose to observe eight {8} gravitationally lensed systems which exhibit quadruple images of the background high redshift quasars. Models invoking a smooth potential fit the observed image positions accurately, in most cases better than 5 milliarcseconds. But the same models dramatically fail to predict the observed flux ratios. These anomalous flux ratios can be attributed to micro- or milli-lensing in the massive lensing halo. In this proposal, we will isolate the source of the anomalous flux ratios by using the superior resolution of HST/STIS to obtain spectrophotometric data and compare the emission line flux ratio of the QSOs to the continuum flux ratios. Due to the much larger size of the broad emission line regions, the flux ratios in the emission lines should only be affected by milli-lensing if the sub-halos are comparable or larger in projected size than the source region. That is, flux ratios observed in the QSO continuum are sensitive to substructure on all scales {both micro- and milli-lensing}, while the broad emission lines are insensitive to micro-lensing due to the larger physical size of the source emission region. This sample of eight quasars will provide the definitive evidence to distinguish between possible sources causing the observed anomalous flux ratios. STIS/CCD/MA1 9848 A SNAPSHOT Survey of Sharp-Lined Early B-Type Stars Although spectrum synthesis studies of the UV spectra of sharp-lined main sequence B stars provide us with some our best determinations of the abundances of the Fe group and neutron capture elements and the chemical evolution in our galaxy and the Magellanic Clouds, the HST archive is virtually devoid of high resolution spectra of the bright nearby B stars that have become to be regarded as abundance standards. For example, there are NO observations of HR 1886, iota Her, and tau Her, the sharpest-lined representatives {V sin i 5 km/s} of spectral classes B1 V, B3 IV-V and B5 IV, and only a few tiny spectral intervals of gamma Peg {B2 IV}. Information on the abundances of the Fe group is important for computing opacities for stellar evolution calculations and for determining astrophysical f-values. There are no suitable galactic standards in the HST database to compare with recent HST/STIS observations of B stars in the Magellanic Clouds and the likely future observations of similar objects in M31 and other nearby galaxies. To correct this deficiency, we propose SNAPSHOT observations with the STIS E140M and E230M gratings of 33 of the best bright abundance standards in nearby clusters and the galactic field. Using this data we will determine the abundances of the Fe group and heavy elements using the technique of spectrum synthesis with LTE and NLTE treatments. We waive the proprietary period. NIC1/NIC2 9844 Brown dwarf atmospheric variability observations We propose to use NIC1 and NIC2 to study brown dwarfs for atmospheric variability. We will observe a sequence of early Ts, a detected variable T2, a T3 and a T4.5. Atmospheric variability, that is expected by some models for these objects, would constrain the physical parameters of cloud vertical distribution, horizontal homogeneity and the dynamics of the very cool atmospheres. The existence and amplitude of the variations would reveal the size and distribution of the cloud cover over the surface of the brown dwarf and test a model explaining the rapidity of the L to T type transition. The relative color changes would constrain the vertical extent of dynamical process and the depth in the atmosphere at which they take place. If a periodicity is measured, the rotational period of the dwarf could be estimated. HST provides the unique and crucial opportunity to observe beyond Earth atmospheric variable absorption, particularly in the important water bands ACS/WFC 9821 The Second Parameter Effect in Metal-Rich Globular Clusters: A Snapshot Study of NGC 6388 While it has long been known that at least one parameter besides the metallicity, [Fe/H], determines the horizontal branch {HB} morphology of Galactic globular clusters {GCs}, our ignorance as to the nature of this second parameter {or parameters} has been a major stumbling block in understanding the formation history and age of the GC system. The hot HB populations recently discovered by HST in the metal-rich GCs NGC 6388 and NGC 6441 provide a unique opportunity for unraveling this second-parameter effect. Many different theories have been proposed to explain the pronounced upward slope of the HBs in these GCs, including stellar rotation, metallicity spread, and a dwarf galaxy origin. We propose to test these theories by obtaining B, V, I time-series photometry of the RR Lyrae variables in the core of NGC 6388 in order to determine whether, as predicted, the pulsation periods are unusually long due to a high HB luminosity. If confirmed, this would argue against age or mass loss as the second parameter in NGC 6388 and, more generally, would have implications for the use of RR Lyrae stars as standard candles for determining GC distances and ages. Light curves will also be obtained for the crowded Population II Cepheids near the core of NGC 6388, the most metal-rich GC, along with NGC 6441, known to contain such stars. We waive proprietary rights to any data obtained. ACS/WFC 9788 A Narrow-band Snapshot Survey of Nearby Galaxies We propose to use ACS/WFC to conduct the first comprehensive HST narrow-band {H-alpha + [N II]} imaging survey of the central regions of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will cover, at high angular resolution extending over a large field, an unprecedented number of galaxies representing many different environments. It will have important applications for many astrophysical problems of current interest, and it will be an invaluable addition to the HST legacy. The observations will be conducted in snapshot mode, drawing targets from a complete sample of 145 galaxies selected from the Palomar spectroscopic survey of nearby galaxies. Our group will use the data for two primary applications. First, we will search for nuclear emission-line disks suitable for future kinematic measurements with STIS, in order to better constrain the recently discovered relations between black hole mass and bulge properties. Preliminary imaging of the type proposed here must be done, sooner or later, if we are to make progress in this exciting new field. Second, we will investigate a number of issues related to extragalactic star formation. Specifically, we will systematically characterize the properties of H II regions and super star clusters on all galactic scales, from circumnuclear regions to the large-scale disk. STIS 9786 The Next Generation Spectral Library We propose to continue the Cycle 10 snapshot program to produce a Next Generation Spectral Library of 600 stars for use in modeling the integrated light of galaxies and clusters. This program is using the low dispersion UV and optical gratings of STIS. The library will be roughly equally divided among four metallicities, very low {[Fe/H] lt -1.5}, low {[Fe/H] -1.5 to -0.5}, near-solar {[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 0.2}, well-sampling the entire HR-diagram in each bin. Such a library will surpass all extant compilations and have lasting archival value, well into the Next Generation Space Telescope era. Because of the universal utility and community-broad nature of this venture, we waive the entire proprietary period. ACS/HRC/WFC 9781 Galaxy Evolution in Action : The Detailed Morphology of Post-Starburst Galaxy If galaxies evolve morphologically, then some should be in transition between late and early types. One proposed evolutionary mechanism is a galaxy-galaxy merger, but evolved merger products are difficult to find. Fortunately, spectroscopic surveys have now uncovered large numbers of E+A galaxies, a class of objects whose post-starburst spectra, current lack of HI gas, and pressure-supported kinematics suggest that they are the missing panel that connects the "Toomre sequence" of merging spirals with normal ellipticals and S0s. Our first HST observations of five of these galaxies are intriguing. We find a considerable range of tidally disturbed morphologies, an "E+A" fundamental plane, significant differences among the color gradients within 1 kpc {~0.8''}, and populations of bright, blue globular clusters. These initial results are difficult to interpret, however, because they are drawn from a small sample of galaxies whose very blue overall colors may have selected a particular evolutionary path of E+As. Here we propose for ACS imaging of the remaining 15 E+As from the Las Campanas Redshift Survey to probe the full range of E+A properties. The proposed observations will allow us to 1} determine what fraction of the interactions that lead to E+As destroy all disk-like structures {and therefore necessarily lead to elliptical formation}, 2} measure the inner color gradients and constrain the spatial distribution of stars produced as gas sinks to the center during a merger, and 3} determine whether these interactions produce globular clusters in the required numbers to account for the increased specific frequency of clusters in early-type galaxies. STIS/CCD 9776 Black Holes in Big Galaxies with Small Bulges In early-type galaxies the black hole {BH} mass is tightly correlated with the bulge velocity dispersion. This correlation suggests that the BH mass is determined by local processes in the central part of the galaxy. However, the bulge dispersion in these galaxies is correlated with the disk circular speed which in turn correlates with the inferred halo circular speed {the "disk-halo conspiracy"}. For this reason, existing data cannot decide whether the BH mass is set by the bulge dispersion or the disk or halo circular speed. We propose to break this degeneracy by weighing the BH in 3 Sc galaxies in which the ratio of bulge circular speed to bulge velocity dispersion is large, leading to large differences between BH masses predicted from these quantities. These measurements will increase the number of carefully studied Sc bulges from one to four and will determine whether the masses of nuclear BHs are set by {presumably baryonic} processes in galaxy bulges or by {presumably non-baryonic} processes in their dark halos. ACS/HRC/WFC 9770 Galaxy Evolution During Half the Age of the Universe: ACS imaging of rich galaxy clusters Detailed studies of nearby galaxies {z0.05} have shown that galaxies have very complex histories of formation and evolution involving mergers, bursts of star formation, and morphological changes. Even so, the global properties of the galaxies {radii, luminosities, rotation velocities, velocity dispersions, and absorption line strengths} follow a number of very tight {empirical} scaling relations, e.g. the Tully-Fisher relation and the Fundamental Plane. These relations place constraints on models for galaxy evolution. The results for nearby galaxies rely on high signal-to-noise spectroscopy and multi-color photometry. With the Gemini Telescopes and the Hubble Space Telescope {HST} it is possible to carry out similar detailed studies of galaxies at much larger redshifts, up to z~1.0, equivalent to half the age of the Universe. We have started a project using the scaling relations and aimed at studying the galaxy evolution over the last half of the age of the Universe. The project is based on a large database of spectroscopy and photometry of galaxies in 15 X-ray selected clusters of galaxies with redshifts between 0.15 and 1.0. Spectroscopic observations are being obtained using both Gemini Telescopes; we have observed 6 clusters so far, covering from z=0.18 to z=0.83. We propose to use HST/ACS to image the clusters and determine the morphologies and measure the sizes of the galaxies. At this time we ask for 26 orbits to image four of the clusters in our sample. STIS/CCD/MA1 9759 Confirmation of New Candidates for the Study of Intergalactic Helium The reionization of intergalactic helium is believed to take place between redshift 3 and 4. The study of HeII Lyman-alpha absorption in four quasars at 2.7z3.3 demonstrates the great potential of such an intergalactic-medium {IGM} probe and suggests that the reionization epoch is at higher redshifts. Clean quasar sightlines may be found only from massive pre-selection processes in the optical and UV, because of random, severe absorption by intervening Lyman-limit systems. The SDSS has discovered approximately 36000 quasars, and we propose to verify the UV detectability in 70 top candidates for helium studies extending to even higher redshift. Our proposed approach has already proven successful, and additional positive confirmations will allow follow-up observations, with STIS, to pinpoint the epoch of reionization of the IGM, and the evolution of its properties near that period. ACS/HRC 9746 Binary systems in the Kuiper Belt The properties of the orbits of Kuiper belt object {KBO} satellites hold keys to fundamental insight into masses and densities of KBOs, the interaction history of the early solar system, the internal structure of distant ice-rock bodies, and even the genesis of the Pluto-Charon binary. Within the past 18 months, 9 KBO satellite systems have been discovered, allowing for the first time the possibility of characterizing a sample of KBO satellite orbital properties. We propose HRC observations to determine satellite orbits in the 6 best cases. We have carefully devised a strategy for each of these 6 systems to make maximum use of ground-based observations, previous HST observations, and the smallest possible number of new HST observations. Our proposed observations will efficiently provide highly reliable orbital solutions which are critical to achieving the scientific promise available from the study of these systems. Our strategy relies heavily on extensive Monte Carlo simulations to define optimal times of observing such that each new point obtained gives maximum leverage for refining the orbital solution. We find that with this strategy we can provide mass solutions for all 6 systems to an accuracy of better than 10% using only 25 new HST observations. This highly efficient program provides extreme scientific output with optimal use of scarce resources. ACS/WFC 9744 HST Imaging of Gravitational Lenses Gravitational lenses offer unique opportunities to study cosmology, dark matter, galactic structure, galaxy evolution and quasar host galaxies. They are also the only sample of galaxies selected based on their mass rather than their luminosity or surface brightness. While gravitational lenses can be discovered with ground-based optical and radio observations, converting them into astrophysical tools requires HST. We will obtain ACS/WFC V and I images and NICMOS H images of 21 new lenses never observed by HST and NICMOS H images of 16 lenses never observed by HST in the IR. As in previous cycles, we request that the data be made public immediately. STIS/CCD/MA1 9736 Integrated Absorption- and Emission-Line Analysis of Nebulae Serious discrepancies have arisen in CNONe abundance determinations for galactic nebulae in the past ten years depending upon which type of emission lines are used in the analysis: forbidden vs. permitted lines. The cause of the discrepancies, which can exceed an order of magnitude for some PNe, has been studied intensively but is still unknown. Emission line abundances cannot be considered reliable until the nature of these contradictory results is understood. We have developed a technique for integrating absorption lines into emission analyses for diffuse nebulae that provides an independent check on the validity of emission-line analyses. It requires high resolution observations of UV resonance absorption produced by the nebular gas in imbedded or background stars together with optical spectra of the nebulae. We propose to obtain UV spectra of four PNe central stars with STIS that will provide data necessary to exploit the new technique of integrated abundance determination that combines both emission and absorption lines. ACS/HRC/WFC 9728 Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae Type Ia supernovae {SNe Ia} provide the only direct evidence for an accelerating universe, an extraordinary result that needs the most rigorous test. The case for cosmic acceleration rests on the observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than they would be in a universe without acceleration. A powerful and straightforward way to assess the reliability of the SN Ia measurement and the conceptual framework of its interpretation is to look for cosmic deceleration at z 1. This would be a clear signature of a mixed dark-matter and dark-energy universe. Systematic errors in the SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia peak luminosity would not show this change of sign. We have obtained a toehold on this putative ``epoch of deceleration'' with SN 1997ff at z = 1.7, and 3 more at z 1 from our Cycle 11 program, all found and followed by HST. However, this is too important a test to rest on just a few objects, anyone of which could be subject to a lensed line-of-sight or misidentification. Here we propose to extend our measurement with observations of twelve SNe Ia in the range 1.0 z 1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be discovered as a byproduct from proposed Treasury and DD programs. These objects will provide a much firmer foundation for a conclusion that touches on important questions of fundamental physics. NIC1/NIC2/NIC3 8792 NICMOS Post-SAA calibration - CR Persistence Part 3 A new procedure proposed to alleviate the CR-persistence problem of NICMOS. Dark frames will be obtained immediately upon exiting the SAA contour 23, and every time a NICMOS exposure is scheduled within 50 minutes of coming out of the SAA. The darks will be obtained in parallel in all three NICMOS Cameras. The POST-SAA darks will be non-standard reference files available to users with a USEAFTER date/time mark. The keyword 'USEAFTER=date/time' will also be added to the header of each POST-SAA DARK frame. The keyword must be populated with the time, in addition to the date, because HST crosses the SAA ~8 times per day so each POST-SAA DARK will need to have the appropriate time specified, for users to identify the ones they need. Both the raw and processed images will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS science/calibration observations started within 50 minutes of leaving an SAA will need such maps to remove the CR persistence from the science images. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors. S/C 4974 TRTTEST No available description ACS/WFC 10268 Recovery of three faint Kuiper Belt Objects discovered with HST We propose 6 orbits to make ACS/WFC follow-up observations of three faint Kuiper Belt Objects {KBOs} that we discovered in the Large Cycle 11 program GO 9433 {G. Bernstein, PI; Bernstein et al. 2004}. These KBOs are the faintest -- and therefore smallest -- KBOs known. Two of these objects can be recovered {and the third easily recovered and its colors probed} only with HST. Any future studies of small KBOs will require knowledge of our three faint KBOs. With the proposed observations, the locations of these KBOs will be known quite well until after first light for JWST. Without the proposed observations, these three small KBOs will be effectively lost. This small program represents a small investment of HST time to solidify the legacy of the Bernstein et al. Large GO program. With the proposed observations, we will be able to determine with certainty the dynamical classes of these three KBOs, testing the hypothesis that small KBOs are predominantly classical KBOs. We will also test the suggestion that classical KBOs are uniformly quite red. Lastly, our observations will enable physical studies {e.g., spectroscopy} with JWST a decade from now. All these measurements will provide important evidence for theories on the formation and evolution of the Solar System. WFPC2 10072 WFPC2 CYCLE 12 INTERNAL MONITOR This calibration proposal is the Cycle 12 routine internal monitor for WFPC2, to be run weekly to monitor the health of the cameras. 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. WFPC2 10070 WFPC2 CYCLE 12 Supplemental Darks Part 2/3 This dark calibration program obtains 3 dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels. WFPC2 10068 WFPC2 CYCLE 12 Standard Darks 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. Over an extended period these data will also provide a monitor of radiation damage to the CCDs. ACS/HRC/WFC 10060 CCD Daily Monitor This program consists of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. This programme will be executed once a day for the entire lifetime of ACS. STIS/MA1 10034 Cycle 12 MAMA Dark Monitor This test performs the routine monitoring of the MAMA detector dark noise. This proposal will provide the primary means of checking on health of the MAMA detectors systems through frequent monitoring of the background count rate. The purpose is to look for evidence of change in dark indicative of detector problem developing. STIS/CCD 10020 CCD Bias Monitor - Part 2 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. STIS/CCD 10018 CCD Dark Monitor-Part 2 Monitor the darks for the STIS CCD. WFPC2/ACS/HRC/WFC 10013 Focus Monitor The focus of HST is measured from WFPC2/PC and ACS/HRC images of stars. Multiple exposures are taken in parallel over an orbit to determine the influence of breathing on the derived mean focus. Observations are taken of clusters with suitable orientations to ensure stars appear in all fields. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9432: GS Acquisition (1,2,1) @ 150/08:34:28Z resulted in FL backup on FGS 2 due to SSLE on FGS 1. Prior FHST FM Updates @ 150/08:22:30Z and 08:25:15Z showed good attitude error vector. FHST Map @ 150/09:17:10Z showed 3-axis (RSS) error value ~ 10.00 arcsec. GS Reacquisitions @ 150/10:11:38Z and 11:47:35Z also resulted in FL backup. GS Reacquisition @ 150/11:47:35Z took two attempts to reach FL due to SSLE on FGS 2. Under investigation. COMPLETED OPS REQs: NONE OPS NOTES EXECUTED: 1115-0 CCC IPCONFIG Connnection 149/11:54z 1241-0 ESTR @ Reconditioning @ 149/23:54z SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 38 38 FGS REacq 35 35 FHST Update 63 63 LOSS of LOCK SIGNIFICANT EVENTS: Successfully uplinked the Battery Reconditioning MACRO, Version D @ 153/10:17:10Z (OR 17175-2 with attached script). Dumped the SPC Table (Table 1, which includes the new MACRO) and compared with the Battery Capacity SPC MACRO load. Zero miscompares and no data missing. Start Battery 4 Capacity Test scheduled 153/10:10Z (OR 17172 with attached script). Three opportunities to connect SA Section 4 to Diode Bus C and their associated discharge terminations are scheduled to ensure no large trickle discharge in the orbit prior to start of test. First opportunity 153/11:10Z - 155/08:10Z, second 153/12:37Z - 155/09:37Z, and third 153/14:18Z - 155/11:18Z. The shadow entry of the first opportunity to start the test is 153/11:01Z. Solar Arrays have been managed to be near normal during the test time-frame. The compatible pointing profile covers the time-frame 153/08:32Z - 156/04:45Z. Continuous Engineering Recording (CER) scheduled 153/09:35Z - 155/17:48Z. In order to receive both engineering and science data during the test and to avoid data recorder overflows, a number of gaps in the CER were planned. Efforts were made to match these gaps to the known times of TDRS return contacts, thereby minimizing the number and duration of the gaps in the CER. A total of four science data playbacks and three engineering data playbacks were scheduled during the CER. The ESTR is required to record engineering data during the SSR science and engineering data playbacks. The ESTR data will be played back only if required (loss of real-time telemetry during SSR playback). See OR 17174 with attached ESTR Record script for details. FGS 3 ITS test scheduled 153/07:51:13Z- 07:58:00:09Z. The expected real-time update to the FGS-2R K16 factor occurs later in this SMS. |
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