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Corrected Daily 3835 - Error corrected in event time
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3835 PERIOD COVERED: DOYs 98-100 OBSERVATIONS SCHEDULED 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. ACS/WFC/WFPC2 10424 The White Dwarf Cooling Age and Dynamical History of the Metal-Poor Globular Cluster NGC 6397 We propose to determine the white dwarf cooling age in the nearest metal-poor {[Fe/H]=- 2} globular cluster, NGC 6397. This globular cluster provides the best opportunity to test the white dwarf cooling age in such a metal-poor system and at the same time provide a comparison with the more metal-rich cluster {M4} which we recently successfully observed with HST. Any {or even no} age difference between these clusters will be important in understanding the age-metallicity relation for these systems which reflects the star formation history in the early Galaxy. The absolute age is an important cosmological constraint. We expect to be able to detect age DIFFERENCES between these clusters at the 0.5 Gyr level and absolute ages should be accurate to 1.0 Gyr. In addition, and in contrast with M4, NGC 6397 is highly dynamically evolved, has a collapsed core, and the distribution of its white dwarfs throughout the cluster have almost certainly been modified by dynamical processes. We are using N-body simulations specifically developed for this cluster to understand these modifications and to include their effects in our measurement of the white dwarf luminosity function and cooling age. Among the dynamical questions we expect to answer with this proposal a 1} what was the primordial binary frequency in NGC 6397? 2} can we explain the high central concentration with a population of massive white dwarfs and/or neutron stars? 3} do we see sufficient central binaries to reverse the core collapse of the cluster? ACS/HRC/WFC 10389 ACS CCDs daily monitor - Cycle 13 - Part 2 This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. ACS/WFC/NIC/NIC3/W 10246 FPC2 The HST survey of the Orion Nebula Cluster We propose a Treasury Program of 104 HST orbits to perform the definitive study of the Orion Nebula Cluster, the Rosetta stone of star formation. We will cover with unprecedented sensitivity {23-25 mag}, dynamic range {~12 mag}, spatial resolution {50mas}, and simultaneous spectral coverage {5 bands} a ~450 square arcmin field centered on the Trapezium stars. This represents a tremendous gain over the shallow WFC1 study made in 1991 with the aberrated HST on an area ~15 times smaller. We maximize the HST observing efficiency using ACS/WFC and WFPC2 in parallel with two opposite roll angles, to cover the same total field. We will assemble the richest, most accurate and unbiased HR diagram for pre-main-sequence objects ever made. Combined with the optical spectroscopy already available for ~1000 sources and new deep near-IR imaging and spectroscopy {that we propose as Joint HST-NOAO observations}, we will be able to attack and possibly solve the most compelling questions on stellar evolution: the calibration of pre-main-sequence evolutionary tracks, mass segration and the variation of the initial mass function in different environments, the evolution of mass accretion rates vs. age and environment, disk dissipation in environments dominated by hard vs. soft-UV radiation, stellar multiplicity vs. disk fraction. In addition, we expect to discover and classify an unknown, but substantial, population of pre-Main Sequence binaries, low mass stars and brown dwarfs down to ~10 MJup. This is also the best possible way to discover dark silhouette disks in the outskirts of the Orion Nebula and study their evolutionary status through multicolor imaging. This program is timely and extremely well leveraged to other programs targeting Orion: the ACS H-alpha survey of the Orion Nebula, the recently completed 850ks ultradeep Chandra survey, the large GTO programs to be performed with SIRTF, plus the availability of 2MASS and various deep JHK surveys of the core recently done with 8m class telescopes. ACS/WFC 10210 Groups of Dwarf Galaxies: Pools of Mostly Dark Matter? Within 5 Mpc, there are 6 groups with well-known luminous galaxies but there also appears to be a comparable number of groups containing only dwarfs. If these dwarf entities are truly bound then M/L values are an order of magnitude higher than values found for groups with luminous spiral galaxies. There are theoretical reasons to anticipate that low mass halos may frequently be mostly dark. The dynamical influence of low mass halos is negligible in familiar groups with luminous members. By contrast, a study of the dynamics of `groups of dwarfs' may provide direct evidence of the existence of dark matter potential wells with few baryons. The goal of the present study is to gather detailed information on the 3-D distribution of dwarf galaxies suspected to lie within 7 groups of dwarfs within 5 Mpc. Distances with 7% relative accuracy can be measured with the Tip of the Giant Branch method with ACS and integrations within 1 orbit per target. NIC2 10173 Infrared Snapshots of 3CR Radio Galaxies Radio galaxies are an important class of extragalactic objects: they are one of the most energetic astrophysical phenomena and they provide an exceptional probe of the evolving Universe, lying typically in high density regions but well-represented across a wide redshift range. In earlier Cycles we carried out extensive HST observations of the 3CR sources in order to acquire a complete and quantitative inventory of the structure, contents and evolution of these important objects. Amongst the results, we discovered new optical jets, dust lanes, face-on disks with optical jets, and revealed point-like nuclei whose properties support FR-I/BL Lac unified schemes. Here, we propose to obtain NICMOS infrared images of 3CR sources with z0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point-like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come. WFPC2 10170 Atmospheric Variability on Uranus and Neptune We propose Snapshot observations of Uranus and Neptune to monitor changes in their atmospheres on time scales of weeks, months, and years. Uranus is rapidly approaching equinox in 2007, with another 4 degrees of latitude becoming visible every year. Recent HST observations during this epoch {including 6818: Hammel, Lockwood, and Rages; 7885: Hammel, Karkoschka, and Marley; 8680: Hammel, Rages, Lockwood, and Marley; and 8634: Rages, Hammel, Lockwood, Marley, and McKay} have revealed strongly wavelength-dependent latitudinal structure and the presence of numerous visible-wavelength cloud features in the northern hemisphere. Long-term ground-based observations {Lockwood and Thompson 1999} show seasonal brightness changes whose origins are not well understood. Recent near-IR images of Neptune obtained using adaptive optics on the Keck Telescope together with images from our Cycle 9 Snapshot program {8634} show a general increase in activity at south temperate latitudes as well as the possible development of another Great Dark Spot. Further Snapshot observations of these two dynamic planets will elucidate the nature of long-term changes in their zonal atmospheric bands and clarify the processes of formation, evolution, and dissipation of discrete albedo features. FGS 10106 An Astrometric Calibration of the Cepheid Period-Luminosity Relation We propose to measure the parallaxes of 10 Galactic Cepheid variables. When these parallaxes {with 1-sigma precisions of 10% or better} are added to our recent HST FGS parallax determination of delta Cep {Benedict et al 2002}, we anticipate determining the Period-Luminosity relation zero point with a 0.03 mag precision. In addition to permitting the test of assumptions that enter into other Cepheid distance determination techniques, this calibration will reintroduce Galactic Cepheids as a fundamental step in the extragalactic distance scale ladder. A Period-Luminosity relation derived from solar metallicity Cepheids can be applied directly to extragalactic solar metallicity Cepheids, removing the need to bridge with the Large Magellanic Cloud and its associated metallicity complications. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR #9764: GSACQ(3,1,1) failed, search radius limit exceeded @ 098/09:47:24z GSacq(3,1,1) at 098/09:42:46 failed to gyro control due to Search Radius Limit Exceeded on FGS 3 at 09:47:24 and a second time at 09:50:27. Roll delay update at 08:45:49 had attitude errors of 5.176 on V1, 1.795 V2, 7.622 V3. Map at 09:51:00 had attitude errors of 4.528, 10.110, -9.884. Observations Affected: ACS 23 to 28, NICMOS 73 to 75, WFPC 205 to 209. The Subsequent REacq(3,1,1) at 098/10:38:17 failed to RGA control. Under investigation. HSTAR #9767: GSaq(1,3,1) failed, search radius limit exceeded @ 098/23:58:31z GSacq(1,3,1) at 098/23:53:36z failed to gyro control due to search radius limit exceed on FGS 1 at 23:58:31z. The REacq at 01:02:01z was successful. Observations Affected: WFPC 224 - 225, NIC 78. Under investigation. HSTAR #9768: REACQ(1,3,1) requires 2 attempts to acquire Fine Lock (FL) @ 100/ 01:04:04z. REACQ(1,3,1) at 100/01:01:38z required two attempts to enter FL, with Scan Step Limit exceeded at 01:04:04z. Second attempt to acquire was successful. Primary GSACQ had no problems. Under investigation. HSTAR #9769: NICMOS suspended, debug exception @ 100/23:3:56z. NICMOS status buffer message 104, Parameter 2, Time 37290, was received at acquisition of signal at 23:07:45. Parameter 2 indicates a DEBUG EXCEPTION occurred. Under investigation. HSTAR #9770: GSACQ(1,3,3) Fine Lock Backup @ 101/06:30:00z. GSACQ(1,3,3) occurred at 05:51:24z while vehicle was LOS. At AOS at 06:30z, vehicle was in Fine Lock on FGS 3 only, QF1STOPF and QSTOP flags were set. Additional information will be available after Engineering Dump is merged. Observations affected: WFPC 9 to 13, ACS 15 to 19, NICMOS 6. Under investigation. Under investigation. COMPLETED OPS REQs: 17416-2 Eclipse Management, GMT Day 098 @ 098/2355z 17417-1 NICMOS Memory Dump after Suspend @ 100/08:42:21z OPS NOTES EXECUTED: 0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 101/0035z 1327-0 Exec 272 while NICMOS is Suspended @ 101/0316z SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 28 26 098/09:47:24z, 098/23:58:31z FGS Reacq 17 16 098/10:38:17z FHST Update 34 34 LOSS of LOCK SIGNIFICANT EVENTS: Eclipse Summary of SE Eclipse Flash Report (Fri, 08 Apr 2005) There were five eclipse events occurring between GMT 98/18:05 to 98/22:39. OPS Request 17416 was successfully executed in preparation for these events by temporarily disabling the Rate of Charge and SA Cold Protection safemode tests. The CSS timer was also modified to prevent software logic from potentially detecting a false CSS failure due to the eclipse. With trickle charge verified and a forward link available following the fifth eclipse, resetting of the safemode tests and CSS timer to their nominal state was completed at 23:55. Preliminary results from limited real-time data appear to indicate that trickle charge was still reached during all but the last eclipse. Near EON at 22:31, the fifth eclipse started as well as a 127.14 deg vehicle maneuver which caused trickle charge not to be reached before start of night as anticipated. Trickle charge was reached in the following orbit day at about 23:50 and EPS is nominal. NICMOS suspended at 100/23:03:46 due to an Intel Debug Exception (ESB 104, P=2). HSTAR 9769 was generated by the FOT. NICMOS memory was successfully dumped via Ops Request 17417 at 101/08:42z and the files transferred to the Payload FSW team for analysis. NICMOS recovery is scheduled to begin at 101/12:50z via Ops Request 17418. |
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