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Daily Report #4844
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT****** #4844 PERIOD COVERED: 5am April 29 - 5am April 30, 2009 (DOY *************************** 119/0900z-120/0900z) OBSERVATIONS SCHEDULED FGS 11788 The Architecture of Exoplanetary Systems Are all planetary systems coplanar? Concordance cosmogony makes that prediction. It is, however, a prediction of extrasolar planetary system architecture as yet untested by direct observation for main sequence stars other than the Sun. To provide such a test, we propose to carry out FGS astrometric studies on four stars hosting seven companions. Our understanding of the planet formation process will grow as we match not only system architecture, but formed planet mass and true distance from the primary with host star characteristics for a wide variety of host stars and exoplanet masses. We propose that a series of FGS astrometric observations with demonstrated 1 millisecond of arc per-observation precision can establish the degree of coplanarity and component true masses for four extrasolar systems: HD 202206 (brown dwarf+planet); HD 128311 (planet+planet), HD 160691 = mu Arae (planet+planet), and HD 222404AB = gamma Cephei (planet+star). In each case the companion is identified as such by assuming that the minimum mass is the actual mass. For the last target, a known stellar binary system, the companion orbit is stable only if coplanar with the AB binary orbit. FGS 11944 Binaries at the Extremes of the H-R Diagram We propose to use HST/Fine Guidance Sensor 1r to survey for binaries among some of the most massive, least massive, and oldest stars in our part of the Galaxy. FGS allows us to spatially resolve binary systems that are too faint for ground-based, speckle or optical long baseline interferometry, and too close to resolve with AO. We propose a SNAP-style program of single orbit FGS TRANS mode observations of very massive stars in the cluster NGC 3603, luminous blue variables, nearby low mass main sequence stars, cool subdwarf stars, and white dwarfs. These observations will help us to (1) identify systems suitable for follow up studies for mass determination, (2) study the role of binaries in stellar birth and in advanced evolutionary states, (3) explore the fundamental properties of stars near the main sequence-brown dwarf boundary, (4) understand the role of binaries for X-ray bright systems, (5) find binaries among ancient and nearby subdwarf stars, and (6) help calibrate the white dwarf mass - radius relation. WFPC2 11973 SAINTS - Supernova 1987A INTensive Survey SAINTS is a program to observe SN 1987A, the brightest supernova since 1604, as it matures into the youngest supernova remnant at age 21. HST is the essential tool for resolving SN1987A's many physical components. A violent encounter is underway between the fastest-moving debris and the circumstellar ring: shocks excite "hotspots." Radio, optical, infrared and X-ray fluxes have been rising rapidly: we have organized Australia Telescope, HST, VLT, Spitzer, and Chandra observations to understand the several emission mechanisms at work. Photons from the shocked ring will excite previously invisible gas outside the ring, revealing the true extent of the mass loss that preceded the explosion of Sanduleak -69 202. This will help test ideas for the progenitor of SN 1987A. The inner debris, excited by radioactive isotopes from the explosion, is now resolved and seen to be aspherical, providing direct evidence on the shape of the explosion itself. Questions about SN 1987A remain unanswered. A rich and unbroken data set from SAINTS will help answer these central questions and will build an archive for the future to help answer questions we have not yet thought to ask. WFPC2 11979 WFPC2 Imaging of Fomalhaut b: Determining its Orbit and Testing for H-alpha Emission Fomalhaut is a bright nearby star that harbors a belt of dusty material with a morphology that has been used to predict the presence of a shepherding planet. With ACS/HRC coronagraphy, we have achieved the direct detection of a planet candidate (Fomalhaut b) in F606W and F814W. The planet candidate lies 18 AU interior to the dust belt and we detect counterclockwise orbital motion in two epochs of observations (2004 and 2006). Fomalhaut b has mass no greater than three Jupiter masses based on an analysis of its luminosity, including non-detections at infrared wavelengths, and the dynamical argument that a significantly more massive object would disrupt the dust belt. Variability at optical wavelengths and the brightness in the F606W passband suggest additional sources of luminosity such as starlight reflected from a circumplanetary ring system. A second possibility that has been invoked for substellar objects is a significant contribution of H-alpha emission. Here we propose follow-up WFPC2 observations to test the possibility that the F606W flux is contaminated by H-alpha emission. We demonstrate that the detection of Fomalhaut b using WFPC2 is feasible using roll deconvolution. Furthermore, a detection of Fomalhaut b in 2009 will provide a crucial third epoch for astrometry. With the existing two epochs of data, the orbit of Fomalhaut b cannot be determined uniquely. The third epoch will be used to test the prediction of apsidal alignment and more accurately determine the dynamical mass of Fomalhaut b. If apsidal mis-alignment is found between the planet and the belt, this result would point to the existence of still other planets lurking unseen in the Fomalhaut system. WFPC2 11988 Searching for Intermediate Mass Black Holes in Globular Clusters via Proper Motions The unambiguous detection of an intermediate mas black hole (IMBH) in a globular star cluster would be a major achievement for the Hubble Space Telescope. It is critical to know whether or not IMBHs exist in the centers of clusters in order to understand the dynamical evolution of dense stellar systems. Also, n IMBH detection would prove the existence of BHs in an entirely new mass range. Observationally, the search has been hampered by the low number of stars with known velocities in the central few arcseconds. This limits measurements of the stellar velocity dispersion in the region where the gravitational influence of any IMBH would be felt. Existing IMBH claims in the literature have all been called into question, and have all been based on line-of-sight velocities from spectroscopy. In cycle 13, we obtained ACS/HRC observations for 5 nearby Galactic globular clusters for a new proper motion study. Here, we request WFPC2/PC observations of these clusters, all of which are observable in Feb-May 2009. This 4 year baseline will allow us to measure the proper motions of stars into the very center of each cluster, and either detect or place firm constraints on the presence of an IMBH. In addition, we will determine whether or not the clusters rotate or show any anisotropy in their motions. Our small (75 orbit) program meets the criteria of addressing high impact science (IMBH detection) using innovative methods (proper motions). FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: (None) COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) *********************** SCHEDULED***** SUCCESSFUL FGS GSAcq************** 06***************** 06 FGS REAcq************** 07***************** 07 OBAD with Maneuver **** 26***************** 26 SIGNIFICANT EVENTS: (None) |
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