Download or read book Evolutionary Scenario for Low mass Stars and Substellar Brown Dwarfs written by Guy S. Stringfellow and published by . This book was released on 1989 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Very Low Mass Stars and Brown Dwarfs written by Rafael Rebolo and published by Cambridge University Press. This book was released on 2000-11-27 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a state-of-the-art review of our current knowledge of brown dwarfs and very low-mass stars. The hunt for and study of these elusive objects is currently one of the most dynamic areas of research in astronomy for two reasons. Brown dwarfs bridge the gap between stars and planets, and they may constitute an important part of the 'dark matter' of the Universe. This volume presents review articles from a team of international authorities who gathered at a conference in La Palma to assess the spectacular progress that has been made in this field in the last few years.
Download or read book 50 Years of Brown Dwarfs written by Viki Joergens and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The years 2012/2013 mark the 50th anniversary of the theoretical prediction that Brown Dwarfs, i.e. degenerate objects which are just not massive enough to sustain stable hydrogen fusion, exist. Some 20 years after their discovery, how Brown Dwarfs form is still one of the main open questions in the theory of star formation. In this volume, the pioneers of Brown Dwarf research review the history of the theoretical prediction and the subsequent discovery of Brown Dwarfs. After an introduction, written by Viki Joergens, reviewing Shiv Kumar's theoretical prediction of the existence of brown dwarfs, Takenori Nakano reviews his and Hayashi's calculation of the Hydrogen Burning Minimum Mass. Both predictions happened in the early 1960s. Jill Tarter then writes on the introduction of the term 'Brown Dwarf', before Ben Oppenheimer, Rafael Rebolo and Gibor Basri describe their first discovery of Brown Dwarfs in the 1990s. Lastly, Michael Cushing and Isabelle Baraffe describe the development of the field to the current state of the art. While the book is mainly aimed at the Brown Dwarf research community, the description of the pioneering period in a scientific field will attract general readers interested in astronomy as well.
Download or read book Brown Dwarf Companions to Young Solar an written by Stanimir Metchev and published by Universal-Publishers. This book was released on 2006-02 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results from an adaptive optics survey conducted with the Palomar and Keck telescopes over 3 years, which measured the frequency of stellar and sub-stellar companions to Sun-like stars. The survey sample contains 266 stars in the 3-10000 million year age range at heliocentric distances between 8 and 200 parsecs and with spectral types between F5-K5. A sub-sample of 101 stars, between 3-500 million years old, were observed in deep exposures with a coronagraph to search for faint sub-stellar companions. A total of 288 candidate companions were discovered around the sample stars, which were re-imaged at subsequent epochs to determine physical association with the candidate host stars by checking for common proper motion. Benefitting from a highly accurate astrometric calibration of the observations, we were able to successfully apply the common proper motion test in the majority of the cases, including stars with proper motions as small as 20 milli-arcseconds/year. The results from the survey include the discovery of three new brown dwarf companions (HD 49197B, HD 203030B, and ScoPMS 214B), 43 new stellar binaries, and a triple system. The physical association of an additional, a priori-suspected, candidate sub-stellar companion to the star HII 1348 is astrometrically confirmed. The newly-discovered and confirmed young brown dwarf companions span a range of spectral types between M5 and T0.5, and will be of prime significance for constraining evolutionary models of young brown dwarfs and extra-solar planets. Based on the 3 new detections of sub-stellar companions in the 101 star sub-sample and following a careful estimate of the survey incompleteness, a Bayesian statistical analysis shows that the frequency of 0.012-0.072 solar-mass brown dwarfs in 30-1600 AU orbits around young solar analogs is 6.8% (-4.9%, +8.3%; 2-sigma limits). While this is a factor of 3 lower than the frequency of stellar companions to G-dwarfs in the same orbital range, it is significantly higher than the frequency of brown dwarfs in 0-3 AU orbits discovered through precision radial velocity surveys. It is also fully consistent with the observed frequency of 0-3 AU extra-solar planets. Thus, the result demonstrates that the radial-velocity "brown dwarf desert" does not extend to wide separations, contrary to previous belief.
Download or read book New Light on Dark Stars written by Neil Reid and published by Springer Science & Business Media. This book was released on 2006-09-01 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been very considerable progress in research into low-mass stars, brown dwarfs and extrasolar planets during the past few years, particularly since the fist edtion of this book was published in 2000. In this new edtion the authors present a comprehensive review of both the astrophysical nature of individual red dwarf and brown dwarf stars and their collective statistical properties as an important Galactic stellar population. Chapters dealing with the observational properies of low-mass dwarfs, the stellar mass function and extrasolar planets have been completely revised. Other chapters have been significantly revised and updated as appropriate, including important new material on observational techniques, stellar acivity, the Galactic halo and field star surveys. The authors detail the many discoveries of new brown dwarfs and extrasolar planets made since publication of the first edition of the book and provide a state-of-the-art review of our current knowledge of very low-mass stars, brown dwarfs and extrasolar planets, including both the latest observational results and theoretical work.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Light on Dark Stars written by Neil Reid and published by Springer. This book was released on 2009-09-02 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been very considerable progress in research into low-mass stars, brown dwarfs and extrasolar planets during the past few years, particularly since the fist edtion of this book was published in 2000. In this new edtion the authors present a comprehensive review of both the astrophysical nature of individual red dwarf and brown dwarf stars and their collective statistical properties as an important Galactic stellar population. Chapters dealing with the observational properies of low-mass dwarfs, the stellar mass function and extrasolar planets have been completely revised. Other chapters have been significantly revised and updated as appropriate, including important new material on observational techniques, stellar acivity, the Galactic halo and field star surveys. The authors detail the many discoveries of new brown dwarfs and extrasolar planets made since publication of the first edition of the book and provide a state-of-the-art review of our current knowledge of very low-mass stars, brown dwarfs and extrasolar planets, including both the latest observational results and theoretical work.
Download or read book Companions and Environments of Low mass Stars written by Kimberly Dolan Ward-Duong and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lowest-mass stars, known as M-dwarfs, form target samples for upcoming exoplanet searches, and together with lower-mass substellar objects known as brown dwarfs, are among prime targets for detailed study with high-contrast adaptive optics (AO) imaging and sub-millimeter interferometry. In this thesis, I describe results from three studies investigating the companion properties and environments of low-mass systems: (1) The 245-star M-dwarfs in Multiples (MinMs) Survey, a volume-limited survey of field M-dwarf companions within 15 pc, (2) the Taurus Boundary of Stellar/Substellar (TBOSS) Survey, an ongoing study of disk properties for low-mass members within the Taurus star-forming region, and (3) spectroscopy of a brown dwarf companion using the Gemini Planet Imager (GPI). Direct imaging of M-dwarfs is a sensitive technique to identify low-mass companions over a wide range of orbital separation, and the high proper motion of nearby M-dwarfs eases confirmation of new multiple stars. Combining AO and wide-field imaging, the MinMs Survey provides new measurements of the companion star fraction (CSF), separation distribution, and mass ratio distribution for the nearest K7-M6 dwarfs. These results demonstrate the closer orbital separations (~6 AU) and lower frequency (~23% CSF) of M-dwarf binaries relative to higher-mass stars. From the TBOSS project, I report 885μm Atacama Large Millimeter/sub-millimeter Array continuum measurements for 24 Taurus members spanning the stellar/substellar boundary (M4-M7.75). Observations of submillimeter emission from dust grains around the lowest-mass hosts show decreasing disk dust mass for decreasing host star mass, consistent with low frequencies of giant planets around M-dwarfs. Compared to the older stellar association of Upper Scorpius, Taurus disks have a factor of four higher mass in submillimeter-sized grains. From the GPI Exoplanet Survey, I describe near-infrared spectroscopy of an unusually red companion orbiting inside the debris disk of an F5V star. As the second brown dwarf discovered within the innermost region of a debris disk, the properties of this system offer important dynamical constraints for companion-disk interaction and a useful benchmark for brown dwarf and giant planet atmospheric study.
Download or read book Dynamics and Multiplicity of Brown Dwarfs and Young Low Mass Stars written by Quinn Morgan Konopacky and published by . This book was released on 2009 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Star Formation and Early Stellar Evolution written by Charles J. Lada and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 779 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin of stars is one of the principle mysteries of nature. During the last two decades advances in technology have enabled more progress to be made in the quest to understand stellar origins than at any other time in history. The study of star formation has developed into one of the most important branches of mod ern astrophysical research. A large body of observational data and a considerable literat ure now exist concerning this topic and a 1arge community of international astronomers and physicists devote their efforts attempting to decipher the secrets of stellar birth. Yet, the young astronomerjphysicist or more advanced researcher desiring to obtain a basic background in this area of research must sift through a very diverse and sometimes bewildering literature. A literature which includes research in many discip1ines and sub discip1ines of classical astrophysics from stel lar structure to the interstellar medium and encompasses the entire range of the electromagnetic spectrum from radio to gamma rays. Often, the reward of a suc cessfu1 foray through the current literature is the realization that the results can be obsolete and outdated as soon as the ink is dry in the journal or the conference proceeding in which they are published.
Download or read book 1 10 Myr old Low Mass Stars and Brown Dwarfs in Nearby Star Forming Regions written by Catherine Louise Slesnick and published by . This book was released on 2008 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Mass Stars and Brown Dwarfs in Open Clusters written by David J. Pinfield and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Low Mass Stars Brown Dwarfs and Extrasolar Planets written by José Gallardo and published by . This book was released on 2007 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Study of Low mass Stars and Brown Dwarfs written by Martin R. Cossburn and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book From Dust To Stars written by Norbert S. Schulz and published by Springer Science & Business Media. This book was released on 2007-03-06 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of stellar formation in galaxies have a profound impact on our understanding of the present and the early universe. The book describes complex physical processes involved in the creation of stars and during their young lives. It illustrates how these processes reveal themselves from radio wavelengths to high energy X-rays and gamma -rays, with special reference towards high energy signatures. Several sections devoted to key analysis techniques demonstrate how modern research in this field is pursued.
Download or read book The Origin of Stars written by Michael David Smith and published by Imperial College Press. This book was released on 2004 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whre do stars come from and how do they form? These are profound questions which link the nature of our Universe to the roots of mankind. Yet, until a recent revolution in understanding, the proposed answers have been raw speculation. Now, accompanying penetrating observations, a new picture has come into prominence. This book presents the latest astounding observations and scientific ideas covering star formation, star birth and early development. It encompasses all aspects, from the dramatic stories of individual objects, to the collective influence of entire stellar systems. The very first stars to come into existence and the nurturing of planets are discussed to provide the reader with a comprehensive overview. Presenting background information with only the essential mathematics, this book will appeal to scientists wishing to expand their horizons, students seeking solid foundations, and general readers with enquiring minds.
Download or read book Low Mass Stars Brown Dwarfs and the Initial Mass Function in Cepheus OB3b written by Simon Thompson and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
