Download or read book Using Small Aperture Interferometry to Detect Planets in Nearby Binary Star Systems written by Douglas G. Currie and published by . This book was released on 1983 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: If suitably accurate binary star orbits can be observed, the effects of planets in the binary star system may be detectable in the reflex motion of the component binary stars. We show that interferometric measurements of binary star systems will provide this information. We discuss the effects of the atmosphere on degrading images and how interferometry will remove these effects to provide very accurate binary star positions relative to the other components in the binary system. Two systems, amplitude interferometry and speckle interferometry, can accomplish this using existing telescopes and techniques. With these methods, nearly accuracies of 0.00002 arc second are possible for binaries of 1 arc second separation and 10000 arc second for a 5 arc binary. These accuracies are more than enough to detect planets in orbits like Jupiter's out to over 20 pc. There are 188 observable systems within 20 pc, in most of which it is possible to have stable planetary orbits similar to solar system orbits. With advanced data recording systems it is possible to observe binary systems where the components are as faint as +16 stellar magnitudes. A dedicated 2-meter interferometric telescope to monitor binary stars could be built for about 1.4 million dollars. (Author).
Download or read book NASA Reference Publication written by and published by . This book was released on 1990 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book An Assessment of Ground Based Techniques for Detecting Other Planetary Systems Volume 2 Position Papers written by and published by . This book was released on 1980 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared Space Interferometry Astrophysics the Study of Earth Like Planets written by C. Eiroa and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past year has produced some of the most exciting results in the history of astronomy, particularly in the area of planets outside our solar system. Only a half-year before our meeting in Toledo, Spain, the first unambiguous detection of planet-sized masses orbiting main sequence stars were reported. Since that time, evidence for a new exo planet has been reported almost at the rate of about once per month. Some of these objects are likely to turn out to be very low-mass stars, but something like half show characteristics - Jupiter-like mass and near-zero orbital eccentricity - which appear to be unique to planets. Almost at the same time that giant planets were being discovered regularly, the two major space agencies, ESA and NASA, have iden tified searches for and detailed study of Earth-like planets as a major priority for the future. In ESA's "Horizon 2000 Plus" programme, an infrared interferometer has been proposed as a possible future Cor nerstone mission. Similarly, scientists in the US produced the "Road Map for the Exploration of Neighboring Planetary Systems (ExNPS)", which provided NASA with a long-term plan which leads also to an infrared interferometer in space to study hypothetical Earth-like worlds beyond our Solar System. Such an observatory is designed to search for the thermal emission from a family of planets, using interferometric nulling to remove the contaminating light from the central star.
Download or read book Life in the Universe written by and published by . This book was released on 1981 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non redundant Aperture Masking Interferometry with Adaptive Optics written by David Wesley Bernat and published by . This book was released on 2012 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents my study of Non-Redundant Aperture Masking Interferometry (or NRM) with Adaptive Optics, a technique for obtaining high-contrast infrared images at diffraction-limited resolution. I developed numerical, statistical, and on-telescope techniques for obtaining higher contrast, in order to build an imaging system capable of resolving massive Jupiter analogs in tight orbits around nearby stars. I used this technique, combined with Laser Guide Star Adaptive Optics (LGSAO), to survey known brown dwarfs for brown dwarf and planetary companions. The diffraction-limited capabilities of this technique enable the detection of companions on short period orbits that make Keplerian mass measurement practical. This, in turn, provides mass and photometric measurements to test brown dwarf evolution (and atmosphere) models, which require empirical constraints to answer key questions and will form the basis for models of giant exoplanets for the next decade. I present the results of a close companion search around 16 known brown dwarf candidates (early L dwarfs) using the first application of NRM with LGSAO on the Palomar 200" Hale Telescope. The use of NRM allowed the detection of companions between 45-360 mas in Ks band, corresponding to projected physical separations of 0.6-10.0 AU for the targets of the survey. Due to unstable LGSAO correction, this survey was capable of detecting primary-secondary contrast ratios down to [INCREMENT]Ks ~1.5-2.5 (10:1), an order of magnitude brighter than if the system performed at specification. I present four candidate brown dwarf companions detected with moderate-to-high confidence (90%-98%), including two with projected physical separations less than 1.5 AU. A prevalence of brown dwarf binaries, if confirmed, may indicate that tight-separation binaries contribute to the total binary fraction more significantly than currently assumed, and make excellent candidates for dynamical mass measurement. For this project, I developed several new, robust tools to reject false positive detections, generate accurate contrast limits, and analyze NRM data in the low signal-to-noise regime. In order to increase the sensitivity of NRM, a critical and quantitative study of quasi-static wavefront errors needs to be undertaken. I investigated the impact of small-scale wavefront errors (those smaller than a sub-aperture) on NRM using a technique known as spatial filtering. Here, I explored the effects of spatial filtering through calculation, simulation, and observational tests conducted with an optimized pinhole and aperture mask in the PHARO instrument at the 200" Hale Telescope. I find that spatially filtered NRM can increase observation contrasts by 10-25% on current AO systems and by a factor of 2-4 on higher-order AO systems. More importantly, this reveals that small scale wavefront errors contribute only modestly to the overall limitations of the NRM technique without very high-order AO systems, and that future efforts need focus on temporal stability and wavefront errors on the scale of the sub-aperture. I also develop a formalism for optimizing NRM observations with these AO systems and dedicated exoplanet imaging instruments, such as Project 1640 and the Gemini Planet Imager. This work provides a foundation for future NRM exoplanet experiments.
Download or read book NASA Conference Publication written by and published by . This book was released on 1981 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Binary Stars as Critical Tools and Tests in Contemporary Astrophysics IAU S240 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2007-08-27 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: IAU S240 focuses on recent advances across the broad field of binary star research.
Download or read book Spatial Interferometry in Optical Astronomy written by Daniel Y. Gezari and published by . This book was released on 1990 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Literature 1997 Part 1 written by Astronomisches Rechen-InstitutARI and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. Two volumes are scheduled to appear per year. Volume 67 records 10,903 papers covering besides the classical fields of astronomy and astrophysics such matters as space flights related to astronomy, lunar and planetary probes and satellites, meteorites and interplanetary matter, X rays and cosmic rays, quasars and pulsars. The abstracts are classified under more than one hundred subject categories thus permitting quick surveying of the bulk of material published on the same topic within six months. For instance, this volume records 119 papers on minor planets, 155 papers on supernovae, and 554 papers on cosmology.
Download or read book Optical Interferometry 2e written by P. Hariharan and published by Elsevier. This book was released on 2003-10-20 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: When the first edition of Optical Interferometry was published, interferometry was regarded as a rather esoteric method of making measurements, largely confined to the laboratory. Today, however, besides its use in several fields of research, it has applications in fields as diverse as measurement of length and velocity, sensors for rotation, acceleration, vibration and electrical and magnetic fields, as well as in microscopy and nanotechnology. Most topics are discussed first at a level accessible to anyone with a basic knowledge of physical optics, then a more detailed treatment of the topic is undertaken, and finally each topic is supplemented by a reference list of more than 1000 selected original publications in total. Historical development of interferometry The laser as a light source Two-beam interference Techniques for frequency stabilization Coherence Electronic phase measurements Multiple-beam interference Quantum effects in optical interference Extensive coverage of the applications of interferometry, such as measurements of length, optical testing, interference microscopy, interference spectroscopy, Fourier-transform spectroscopy, interferometric sensors, nonlinear interferometers, stellar interferometry, and studies of space-time and gravitation
Download or read book Dynamic Astronomy in Latin America written by Carlos Abad and published by UNAM. This book was released on 2006 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Third International Meeting of Dynamic Astronomy in Latin America, (Tercera Reunion sobre Astronomıa Dinamica en Latino-America) which we named ADeLA-2004, was held on November 22-24, 2004 in Merida. It represents the consolidation and continuity of a series of meetings about Astrometry and related topics. The first meeting took place in 2001 in San Juan (Argentina), followed by the second meeting in 2002 in Araraquara (Brazil). Astrometry, after an original and basic contribution not only to Astronomy as a branch of science but also to the direct development of society, starts declining when in the middle of the twentieth century it gets far from astrophysical research and the human mind finds alternative ways to solve the upcoming development problems. This fact has progressively made the financing models for scientific projects focus on and expandtowards the more "productive" areas of Astronomy, leaving aside Astrometry, which we consider a vital area. Even when preparing themselves academically, the astrometrists with their meticulous work, do not find easily government support and ways to compete. The rapid development of detectors and observation techniques during the last decade has almost completely transformed Astronomy. The data collected from observation are once again the main source for the theoreticaldevelopment of this science. Moreover, observations have often changed many theoretical concepts. Astrometry has not been left behind and the future, almost magical, observations include the space projectssuch as GAIA and SIM. These projects should be seen as the spur for the adaptation of Astrometry to the new era, making this area a basic one in the professional training of any astronomer. The astrometrist is the one whomust enlarge his scope to encompass data interpretation, taking advantage of the meticulous and craftsman-like character that this work has always had in order to access the big data bases that will be generated and arein danger of being considered as sources of statistical information. This concern for the future of Astrometry was discussed in this meeting. ADeLA-2004 had two additional innovations. The first one consisted in including a workshop, or a series of conferences on topics related to Astrometry, addressed to students interested in astronomy. This meeting has offered the opportunity to gather important foreign researchers. The participation of ESO Vitacura (Chile) researchers in ADeLA 2004, as well as the usual ADeLA meeting participants, facilitated a wide and diverseseries of lectures on related topics. These lectures were addressed both in a pedagogical and a professional atmosphere which encouraged Venezuelan undergraduate, and graduate students interested in or majoring in astronomy, to participate in both events. The so-called "Taller de ADeLA-2004" took place after the meeting on November 25 and 26. The workshop improved the relationships between the Venezuelan scientific and student communities."
Download or read book Aperture Synthesis written by Swapan Kumar Saha and published by Springer Science & Business Media. This book was released on 2010-10-17 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the fundamentals of stellar interferometry with emphasis on aperture synthesis using sparse array of telescopes particularly at optical/IR wavelengths, the origin, properties, and optical effects of turbulence in the Earth's atmosphere, techniques developed to overcome image degradation. Studded with more than one hundred and fifty illustrations and tens of footnotes, it addresses the basic tricks of trade, current trend, motivation, methods, and path to future promise of true interferometry both from the ground and space. Also discussed are the technical challenge involved, such as beam transportation and recombination, detecting fringes using modern sensors, and image synthesis. Astronomical science that benefits from aperture synthesis imaging are highlighted as well.
Download or read book Science with the VLT Interferometer written by Francesco Paresce and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has always been ESO's aim to operate the VLT in an interferometric mode (VLTI) which allows the coherent combination of stellar light beams col lected by the four 8-m telescopes and by several smaller auxiliary telescopes. In December 1993, in response to financial difficulties, the ESO Council de cided to postpone implement at ion of the VLTI, Coude trains and associated adaptive optics for all the UTs but included provisions for continuing tech nological and development programmes devoted to the aim of reintroducing these capabilities at the earliest possible date. The desirability of carrying out the full VLTI programme as originally envisaged at the earliest possible moment has not, however, diminished, es pecially in view of VLTI's exceptional capabilities and resulting potential for new and exciting discoveries. In recent years, interferometric projects have begun to playa central role in ground-based high-resolution astronomy, and numerous instruments have been completed or are in the process of construc tion. Several large-aperture interferometers will probably co me on-line near the turn of the century. The impending presence of these new instruments represents an important incentive both for clarifying the scientific cases for various VLTI implementation plans and for ensuring VLTI's competitiveness in the international context over the next 1O~20 years.
Download or read book The Exoplanet Handbook written by Michael Perryman and published by Cambridge University Press. This book was released on 2018-08-30 with total page 973 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the discovery of planets beyond our solar system 25 years ago, exoplanet research has expanded dramatically, with new state-of-the-art ground-based and space-based missions dedicated to their discovery and characterisation. With more than 3,500 exoplanets now known, the complexity of the discovery techniques, observations and physical characterisation have grown exponentially. This Handbook ties all these avenues of research together across a broad range of exoplanet science. Planet formation, exoplanet interiors and atmospheres, and habitability are discussed, providing in-depth coverage of our knowledge to date. Comprehensively updated from the first edition, it includes instrumental and observational developments, in-depth treatment of the new Kepler mission results and hot Jupiter atmospheric studies, and major updates on models of exoplanet formation. With extensive references to the research literature and appendices covering all individual exoplanet discoveries, it is a valuable reference to this exciting field for both incoming and established researchers.
Download or read book Literature 1982 Part 2 written by Siegfried Böhme and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 857 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documenta tion of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, compared to which our system of accumu lating abstracts for about six months offers the advantage of greater convenience for the user. Volume 32 contains literature published in 1982 and received before February 11, 1983; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bou~a, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English.
