998 resultados para Transit Planning


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Photometric transit surveys promise to complement the currently known sample of extra-solar planets (ESPs) by providing additional information on the planets and especially their radii. Here, we present ESP candidates from one such survey called, the Wide Angle Search for Planets (WASP) obtained with the SuperWASP wide-field imaging system. Observations were taken with SuperWASP North located in La Palma during the 2004 April to October observing season. The data cover fields between 23 and 03 h in RA at declinations above +12. This amounts to over ~400000 stars with V magnitudes 8-13.5. For the stars brighter than 12.5, we achieve better than 1 per cent photometric precision. Here, we present 41 sources with low-amplitude variability between ~1 and 10 mmag, from which we select 12 with periods between 1.2 and 4.4 d as the most promising ESP candidates. We discuss the properties of these ESP candidates, the expected fraction of transits recovered for our sample and implications for the frequency and detection of hot-Jupiters.

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We present a fast and efficient hybrid algorithm for selecting exoplanetary candidates from wide-field transit surveys. Our method is based on the widely used SysRem and Box Least-Squares (BLS) algorithms. Patterns of systematic error that are common to all stars on the frame are mapped and eliminated using the SysRem algorithm. The remaining systematic errors caused by spatially localized flat-fielding and other errors are quantified using a boxcar-smoothing method. We show that the dimensions of the search-parameter space can be reduced greatly by carrying out an initial BLS search on a coarse grid of reduced dimensions, followed by Newton-Raphson refinement of the transit parameters in the vicinity of the most significant solutions. We illustrate the method's operation by applying it to data from one field of the SuperWASP survey, comprising 2300 observations of 7840 stars brighter than V = 13.0. We identify 11 likely transit candidates. We reject stars that exhibit significant ellipsoidal variations caused indicative of a stellar-mass companion. We use colours and proper motions from the Two Micron All Sky Survey and USNO-B1.0 surveys to estimate the stellar parameters and the companion radius. We find that two stars showing unambiguous transit signals pass all these tests, and so qualify for detailed high-resolution spectroscopic follow-up.

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The purpose of this paper is to expose the concept of collaborative planning to the reality of planning, thereby assessing its efficacy for informing and explaining what planners 'really' do and can do. In this systematic appraisal, collaborative planning is disaggregated into four elements that can enlighten such conceptual frameworks: ontology, epistemology, ideology and methodology. These four lenses help delimit and clarify collaborative planning's strengths and weaknesses. The conceptual debate is related to an empirical investigation of planning processes, ranging from region-wide to local and from statutory to visionary in an arena where special care has been invested in participatory deliberation processes. The final analysis provides a systematic gauge of collaborative planning in light of the extensive empirical evidence, deploying the four conceptual dimensions introduced in part one. This exposes a range of problems not only with the concept itself but also regarding its affinity with the uncollaborative world within which it has to operate. The former shed light on those aspects where collaborative planning as a conceptual tool for practitioners needs to be renovated, while the latter highlight inconsistencies in a political framework that struggles to accommodate both global competitiveness and local democratic collaboration.

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This paper describes a method for working with chldren who are the subjects of care planning and review under the Children Act 1989. The person centred planning model, as it is termed, has been well established in working with adults with special needs but can be extrapolated to encounters with children. It focuses on three fundamental areas: relationship, meaning and narrative. In underscoring these areas, the method restrains the bureaucracy and experience of stigma that is often present for those residing in State care.