Ground-based Astronomy


Book Description







Assessment of Options for Extending the Life of the Hubble Space Telescope


Book Description

The Hubble Space Telescope (HST) has operated continuously since 1990. During that time, four space shuttle-based service missions were launched, three of which added major observational capabilities. A fifth â€" SM-4 â€" was intended to replace key telescope systems and install two new instruments. The loss of the space shuttle Columbia, however, resulted in a decision by NASA not to pursue the SM-4 mission leading to a likely end of Hubble's useful life in 2007-2008. This situation resulted in an unprecedented outcry from scientists and the public. As a result, NASA began to explore and develop a robotic servicing mission; and Congress directed NASA to request a study from the National Research Council (NRC) of the robotic and shuttle servicing options for extending the life of Hubble. This report presents an assessment of those two options. It provides an examination of the contributions made by Hubble and those likely as the result of a servicing mission, and a comparative analysis of the potential risk of the two options for servicing Hubble. The study concludes that the Shuttle option would be the most effective one for prolonging Hubble's productive life.




Astronomical Optics


Book Description

Written by a recognized expert in the field, this clearly presented, well-illustrated book provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today. - Written by a recognized expert in the field - Provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today




Frontiers Of Space And Ground-Based Astronomy


Book Description

ROSAT Observations G. HASINGER Max-Planck-Institut flir extraterrestrische Physik, D-85740 Garching, Germany Abstract. This review describes the most recent advances in the study of the extragalactic soft X-ray background and what we can learn about its constituents. The deepest pointed observations with the ROSAT PSPC are discussed. The logN-logS relation is presented, which reaches to the faintest X-ray fluxes and to the highest AGN surface densities ever achieved. The N(>S) relation shows a 2 density in excess of 400 deg- at the faintest fluxes and a flattening below the Einstein Deep Survey limit. About 60% of the extragalactic background has been resolved in the deepest field. Detailed source spectra and first optical and radio identifications will be discussed. The results are put into perspective of the higher energy X -ray background. Key words: X-rays, background radiations, active galactic nuclei. 1. Introduction The extragalactic X-ray background (XRB), discovered about 30 years ago, has been studied extensively with many X-ray experiments, in particular with the satel lites HEAO I and II (see ego Boldt 1987) and with ROSAT (e. g. Hasinger et aI. , 1993). Figure 1 shows a compilation of some of the most recent spectral measure ments for the X-ray background. Over the energy range from 3 to about 100 keY its spectrum can be well approximated by an optically thin thermal bremsstrahlung model with kT ~ 40 keY, while at lower X-ray energies a steepening into a new component has been observed observed (e. g.




Adaptive Optics in Astronomy


Book Description

Adaptive optics is set to revolutionise the future of astronomy; this is the first book on the subject and is set to become the standard reference.




Integrated Modeling of Telescopes


Book Description

Ground- or space-based telescopes are becoming increasingly more complex and construction budgets are typically in the billion dollar range. Facing costs of this magnitude, availability of engineering tools for prediction of performance and design optimization is imperative. Establishment of simulation models combining different technical disciplines such as Structural Dynamics, Control Engineering, Optics and Thermal Engineering is indispensable. Such models are normally called Integrated Models because they involve many different disciplines. The models will play an increasingly larger role for design of future interdisciplinary optical systems in space or on ground. The book concentrates on integrated modeling of optical and radio telescopes but the techniques presented will be applicable to a large variety of systems. Hence, the book will be of interest to optical and radio telescope designers, designers of spacecrafts that include optical systems, and to designers of various complex defense systems. The book may also find use as a textbook for undergraduate and graduate courses within the field. "Adaptive Optics" is an exciting and relatively new field, originally dedicated to correction for blurring when imaging through the atmosphere. Although this objective is still of high importance, the concept of Adaptive Optics has recently evolved further. Today, the objective is not only to correct for atmospheric turbulence effects but also for a range of static and dynamical telescope aberrations. The notion of adaptive optics has expanded to the field of "Wavefront Control", correcting for a variety of system aberrations. Wavefront control systems maintain form and position of optical elements with high precision under static and dynamical load. In many ways, such systems replace the steel structures of traditional optical systems, thereby providing much lighter systems with a performance not possible before. Integrated Modeling is the foremost tool for studies of Wavefront Control for telescopes and complex optics and is therefore now of high importance. Springer has recently published two books on telescopes, "Reflecting Telescope Optics" by R. Wilson, and "The Design and Construction of Large Optical Telescopes" by P. Bely. Noting that a new (and expensive) generation of Extremely Large Telescopes with apertures in the 30-100 m range is on the way, the present book on integrated modeling is a good match to the existing books and an appropriate specialization and continuation of some subjects dealt with in those books.




Giant Telescopes


Book Description

Every night, astronomers use a new generation of giant telescopes at observatories around the world to study phenomena at the forefront of science. By focusing on the history of the Gemini ObservatoryÑtwin 8-meter telescopes located on mountain peaks in Hawaii and ChileÑGiant Telescopes tells the story behind the planning and construction of modern scientific tools, offering a detailed view of the technological and political transformation of astronomy in the postwar era. Drawing on interviews with participants and archival documents, W. Patrick McCray describes the ambitions and machinations of prominent astronomers, engineers, funding patrons, and politicians in their effort to construct a modern facility for cutting-edge scienceÑand to establish a model for international cooperation in the coming era of Òmegascience.Ó His account details the technological, institutional, cultural, and financial challenges that scientists faced while planning and building a new generation of giant telescopes. Besides exploring how and why scientists embraced the promise and potential of new technologies, he considers how these new tools affected what it means to be an astronomer. McCrayÕs book should interest anyone who desires a deeper understanding of the science, technology, and politics behind finding our place in the universe.




The Perfect Machine


Book Description

Author describes the building of the Palomar telescope in California, one of the greatest technical achievements of this century.




Ultraviolet Astronomy and the Quest for the Origin of Life


Book Description

Ultraviolet Astronomy and the Quest for the Origin of Life addresses the use of astronomical observations in the ultraviolet range to better understand the generation of complex, life-precursor molecules. The origin of RNA is still under debate but seems to be related to the generation of pools of complex organic molecules submitted to heavy cycles of solution in water and drying. This book investigates whether these cycles require a planetary surface or may occur in space by examining both the theoretical and observational aspects of the role of UV radiation in the origin of life. This book offers the latest advances in these studies for astronomers, astrobiologists and planetary scientists. - Addresses both the theoretical and observational aspects of the role of Ultraviolet (UV) radiation in the origin of life - Builds on the requirements to produce prebiotic molecules in space and the implications for the origin of RNA - Investigates the use of ultraviolet observations related to planetary system formation, the evolution of young planetary disks, and the interaction of stars with planetary atmospheres




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