Download or read book The Detection and Characterization of Low Mass Companions to Sun Like Stars written by James Patrick Lloyd and published by . This book was released on 2002 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopic Detection and Characterization of Extreme Flux ratio Binary Systems written by Kevin Carl Gullikson and published by . This book was released on 2016 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary stars and higher-order multiple systems are a ubiquitous outcome of star formation, especially as the system mass increases. The companion mass-ratio distribution is a unique probe into the conditions of the collapsing cloud core and circumstellar disk(s) of the binary fragments. Inside a ~1000 AU the disks from the two forming stars can interact, and additionally companions can form directly through disk fragmentation. We might therefore expect the mass-ratio distribution of close companions to differ from that of wide companions. This prediction is difficult to test with intermediate-mass primary stars using traditional methods because the contrast ratios that would be required to detect low-mass companions at narrow working angles are not yet achievable. In this thesis, we present a spectroscopic method to detect and characterize close companions to a variety of stars. We demonstrate applications of the method to detection of stars and even planets around sun-like stars, and present the results of a survey searching for companions to A- and B-type stars. As part of the survey, we estimate the temperatures and surface gravity of most of the 341 sample stars, and derive their masses and ages. We additionally estimate the temperatures and masses of the 64 companions we find, 23 of which are new detections. We find that the mass-ratio distribution for our sample has a turnover near q ~0.3, in contrast to the scale-free power law that describes the widely separated binary systems. We take this characteristic scale as evidence that companions are accreting a significant of material through disk interactions as they form, and that the scale is largely set by the disk lifetime and the time at which the fragments form.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Topics in Adaptive Optics written by Robert Tyson and published by BoD – Books on Demand. This book was released on 2012-01-20 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in adaptive optics technology and applications move forward at a rapid pace. The basic idea of wavefront compensation in real-time has been around since the mid 1970s. The first widely used application of adaptive optics was for compensating atmospheric turbulence effects in astronomical imaging and laser beam propagation. While some topics have been researched and reported for years, even decades, new applications and advances in the supporting technologies occur almost daily. This book brings together 11 original chapters related to adaptive optics, written by an international group of invited authors. Topics include atmospheric turbulence characterization, astronomy with large telescopes, image post-processing, high power laser distortion compensation, adaptive optics and the human eye, wavefront sensors, and deformable mirrors.
Download or read book Understanding Information written by Alfons Josef Schuster and published by Springer. This book was released on 2017-07-26 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: The motivation of this edited book is to generate an understanding about information, related concepts and the roles they play in the modern, technology permeated world. In order to achieve our goal, we observe how information is understood in domains, such as cosmology, physics, biology, neuroscience, computer science, artificial intelligence, the Internet, big data, information society, or philosophy. Together, these observations form an integrated view so that readers can better understand this exciting building-block of modern-day society. On the surface, information is a relatively straightforward and intuitive concept. Underneath, however, information is a relatively versatile and mysterious entity. For instance, the way a physicist looks at information is not necessarily the same way as that of a biologist, a neuroscientist, a computer scientist, or a philosopher. Actually, when it comes to information, it is common that each field has its domain specific views, motivations, interpretations, definitions, methods, technologies, and challenges. With contributions by authors from a wide range of backgrounds, Understanding Information: From the Big Bang to Big Data will appeal to readers interested in the impact of ‘information’ on modern-day life from a variety of perspectives.
Download or read book Planets in Binary Systems written by Lea Hirsch and published by . This book was released on 2018 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nearly half of all solar-type stars have at least one stellar or brown dwarf companion, and planets around G- and K-type stars appear to be quite common. Yet the impact of stellar multiplicity on planets, and on our understanding of planets, is not well understood. In this thesis, I describe a combination of work to study the interplay between stellar and planetary companions, using the combination of radial velocity and high-resolution imaging observations. First, planets discovered by transit surveys like the \eke Mission are sensitive to a detection and characterization bias due to stellar companions. The light of unresolved binary companions dilutes the transit of the planet, making it appear shallower than it is. This causes planet sizes in binary systems to be underestimated, and sensitivity to small planets to be overestimated. In Chapter 2, I combined multi-wavelength observations of stellar companions detected within 2 arcseconds of 170 Kepler Object of Interest hosts, to assess whether these companions were physically associated with the planet host stars. I found that stellar companions within 1" had a >80% likelihood of being bound. I used the compiled imaging observations of the bound stellar companions in this sample to determine the factor by which planet radii in these systems were underestimated. I determined that an average radius correction factor of X_R = 1.65 must be applied to planets orbiting stars with unresolved stellar companions, assuming the planets are equally likely to orbit either of the stars in a binary system. This means that planets in unresolved binary systems may have radii underestimated by an average of 65%. This effect is particularly important for Kepler stars with minimal ground-based follow-up; by performing a combination of spectroscopic and imaging observations on Kepler planet hosts, it is possible to reduce the effect of stellar companions by finding or ruling out binary companions in large regions of parameter space. Second, stellar companions likely impact the formation and evolution of planetary systems. To probe these effects, I focused on the solar neighborhood, studying sun-like stars within 25 pc using Doppler spectroscopy as well as adaptive optics and speckle imaging techniques. I built up methodology for performing joint orbital fits to combinations of radial velocity, astrometric, and photometric data by assessing the orbit of HD 159062 in Chapter 3. HD 159062 is a nearby binary system consisting of a G dwarf and a newly-discovered white dwarf companion. I determined that the white dwarf must have a mass of 0.54^{+0.09}_{-0.03} solar masses. Its combined radial velocities, astrometry, and photometry are inconsistent with it being either a brown dwarf or a main sequence star. In Chapter 4, I extended this joint orbital analysis technique to make use of imaging non-detections to place constraints on orbiting planets. In this study, we focused on the nearby adolescent K dwarf, Epsilon Eridani, whose giant planet was detected in three decades of radial velocity monitoring. Using deep M-band coronographic imaging that resulted in no detection of the planet, upper limits were placed on the mass of the giant planet. The combination of the RV data and constraints from the non-detection of the planet allowed the mass and inclination of the planet to be determined more precisely than with the RV data alone. Finally, I performed a simultaneous RV and imaging survey for both stellar and planetary companions to sun-like stars in the solar neighborhood in Chapter 5. By comparing the planet occurrence rates in binary systems to those in single star systems, we can begin to untangle the effects of stellar companions on planet formation. I found that the occurrence rate of planets with masses between 0.1 and 10 Jupiter masses and with semi-major axes between 0.1 and 10 AU is statistically equivalent in single star and binary star systems. I also determined that all known planet-hosting binary systems in the 25 pc sun-like star sample had separations wider than 100 AU. This indicates that wide binary companions do not seem to strongly impact the planet formation process, but that the planet occurrence rate in binary systems may decrease for systems with smaller binary separations.
Download or read book Encyclopedia of Astrobiology written by Muriel Gargaud and published by Springer Science & Business Media. This book was released on 2011-05-26 with total page 1890 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astrobiology is a remarkably interdisciplinary field. This reference serves as a key to understanding technical terms from the different subfields of astrobiology, including astronomy, biology, chemistry, the geosciences and the space sciences.
Download or read book Exoplanet Science Strategy written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-01-17 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past decade has delivered remarkable discoveries in the study of exoplanets. Hand-in-hand with these advances, a theoretical understanding of the myriad of processes that dictate the formation and evolution of planets has matured, spurred on by the avalanche of unexpected discoveries. Appreciation of the factors that make a planet hospitable to life has grown in sophistication, as has understanding of the context for biosignatures, the remotely detectable aspects of a planet's atmosphere or surface that reveal the presence of life. Exoplanet Science Strategy highlights strategic priorities for large, coordinated efforts that will support the scientific goals of the broad exoplanet science community. This report outlines a strategic plan that will answer lingering questions through a combination of large, ambitious community-supported efforts and support for diverse, creative, community-driven investigator research.
Download or read book Planetary Astrobiology written by Victoria Meadows and published by University of Arizona Press. This book was released on 2020-07-07 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Are we alone in the universe? How did life arise on our planet? How do we search for life beyond Earth? These profound questions excite and intrigue broad cross sections of science and society. Answering these questions is the province of the emerging, strongly interdisciplinary field of astrobiology. Life is inextricably tied to the formation, chemistry, and evolution of its host world, and multidisciplinary studies of solar system worlds can provide key insights into processes that govern planetary habitability, informing the search for life in our solar system and beyond. Planetary Astrobiology brings together current knowledge across astronomy, biology, geology, physics, chemistry, and related fields, and considers the synergies between studies of solar systems and exoplanets to identify the path needed to advance the exploration of these profound questions. Planetary Astrobiology represents the combined efforts of more than seventy-five international experts consolidated into twenty chapters and provides an accessible, interdisciplinary gateway for new students and seasoned researchers who wish to learn more about this expanding field. Readers are brought to the frontiers of knowledge in astrobiology via results from the exploration of our own solar system and exoplanetary systems. The overarching goal of Planetary Astrobiology is to enhance and broaden the development of an interdisciplinary approach across the astrobiology, planetary science, and exoplanet communities, enabling a new era of comparative planetology that encompasses conditions and processes for the emergence, evolution, and detection of life.
Download or read book From Giant Planets to Cool Stars written by Caitlin A. Griffith and published by . This book was released on 2000 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Contains papers from a June 1999 workshop addressing the emerging interdisciplinary field of brown dwarfs and extrasolar giant planets. Principal topics discussed are atmospheric structure and chemistry, dynamics, condensation, interior structure, and the evolution of extra-solar planets and brown dwarfs. Some specific topics include the nature and origin of low-mass companions to stars, discovering T dwarfs with 2MASS, the exotic atmospheres of substellar-mass objects, narrow-band near infrared photometry of brown dwarfs, and photochemistry in giant-planet atmospheres. Griffith is affiliated with Northern Arizona University. Marley is affiliated with New Mexico State University. Lacks a subject index. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Download or read book New Worlds New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
Download or read book Beyond the Blur written by Shriharsh P. Tendulkar and published by Universal-Publishers. This book was released on 2014-06-04 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics (AO) corrects distortions created by atmospheric turbulence and delivers diffraction-limited images on ground-based telescopes. The vastly improved spatial resolution and sensitivity has been utilized for studying everything from the magnetic fields of sunspots upto the internal dynamics of high-redshift galaxies. This thesis about AO science from small and large telescopes is divided into two parts: Robo-AO and magnetar kinematics. In the first part, I discuss the construction and performance of the world's first fully autonomous visible light AO system, Robo-AO, at the Palomar 60-inch telescope. Robo-AO operates extremely efficiently with an overhead
Download or read book Planets Beyond the Solar System and the Next Generation of Space Missions written by David R. Soderblom and published by . This book was released on 1997 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Origins of Life Volume II written by Vladivoj Valkovic and published by CRC Press. This book was released on 2024-09-27 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Origins of Life Volume II, life and its origin are inspected from traditional and unexpected points of view. The book takes an interdisciplinary approach, discussing astrobiology; chemical evolution; and how the Universe accommodates life, molecular biology, and philosophy. It is an open-minded approach, fully referenced throughout, and each chapter includes a further reading section for anyone wishing to learn more about that perspective on the origins of life. First, everything started, with the Big Bang, from nothing. It appears now that everything was aiming toward our existence, some 13.75 × 109 years later, being capable of understanding it all. We did it using powerful tools: science, philosophy, and religion. Although we appreciate the contributions made by philosophy and religion, our contemplations and doubts are based on the plentiful scientific evidence provided. The reader will be guided from make-up of the "life stage" (Universe), tools and materials needed for the living matter to be formed in the small part of the Universe, which one could call Human Neighborhood, or the Local Universe. It contains galaxies, galaxy clusters, and voids, and the Milky Way and its satellites influencing each other during this time span. The book is easy to read, accompanied by numerous references; it could be of use to the expert in the field as well as for curious minds with a scientific, philosophical, or religious background.
Download or read book Space Telescopes and Instruments written by and published by . This book was released on 1998 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Telescopes and Instruments V written by Pierre-Yves Bely and published by . This book was released on 1998 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Astrobiology written by Vera M. Kolb and published by CRC Press. This book was released on 2018-12-07 with total page 866 pages. Available in PDF, EPUB and Kindle. Book excerpt: Choice Recommended Title, August 2019 Read an exclusive interview with Professor Vera Kolb here. Astrobiology is the study of the origin, evolution, distribution, and future of life on Earth. This exciting and significant field of research also investigates the potential existence and search for extra-terrestrial life in the Solar System and beyond. This is the first handbook in this burgeoning and interdisciplinary field. Edited by Vera Kolb, a highly respected astrobiologist, this comprehensive resource captures the history and current state of the field. Rich in information and easy to use, it assumes basic knowledge and provides answers to questions from practitioners and specialists in the field, as well as providing key references for further study. Features: Fills an important gap in the market, providing a comprehensive overview of the field Edited by an authority in the subject, with chapters written by experts in the many diverse areas that comprise astrobiology Contains in-depth and broad coverage of an exciting field that will only grow in importance in the decades ahead
