Introduction to Brown Dwarfs
Author: John Gizis
Publisher: AAS-IOP Astronomy
Published: 2022-12-15
Total Pages: 0
ISBN-13: 9780750333856
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50 Years of Brown Dwarfs
Author: Viki Joergens
Publisher: Springer Science & Business Media
Published: 2013-11-27
Total Pages: 174
ISBN-13: 3319011626
DOWNLOAD EBOOK →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.
Very Low-Mass Stars and Brown Dwarfs
Author: Rafael Rebolo
Publisher: Cambridge University Press
Published: 2000-11-27
Total Pages: 284
ISBN-13: 9780521663359
DOWNLOAD EBOOK →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.
New Light on Dark Stars
Author: Neill I. Reid
Publisher: Springer Science & Business Media
Published: 2013-11-27
Total Pages: 492
ISBN-13: 1447136632
DOWNLOAD EBOOK →Perhaps the most common question that a child asks when he or she sees the night sky from a dark site for the first time is: 'How many stars are there?' This happens to be a question which has exercised the intellectual skills of many astronomers over the course of most of the last century, including, for the last two decades, one of the authors of this text. Until recently, the most accurate answer was 'We are not certain, but there is a good chance that almost all of them are M dwarfs. ' Within the last three years, results from new sky-surveys - particularly the first deep surveys at near infrared wavelengths - have provided a breakthrough in this subject, solidifying our census of the lowest-mass stars and identifying large numbers of the hitherto almost mythical substellar-mass brown dwarfs. These extremely low-luminosity objects are the central subjects of this book, and the subtitle should be interpreted accordingly. The expression 'low-mass stars' carries a wide range of meanings in the astronomical literature, but is most frequently taken to refer to objects with masses comparable with that of the Sun - F and G dwarfs, and their red giant descendants. While this definition is eminently reasonable for the average extragalactic astronomer, our discussion centres on M dwarfs, with masses of no more than 60% that of the Sun, and extends to 'failed stars' - objects with insufficient mass to ignite central hydrogen fusion.
Brown Dwarf Companions to Young Solar an
Author: Stanimir Metchev
Publisher: Universal-Publishers
Published: 2006-02
Total Pages: 255
ISBN-13: 158112290X
DOWNLOAD EBOOK →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.
The Physics of Low-Mass Stars, Brown Dwarfs and Gaseous Planets
Author: Gilles Chabrier
Publisher: World Scientific Publishing Company
Published: 2014-12-31
Total Pages: 250
ISBN-13: 9789814390316
DOWNLOAD EBOOK →This book provides a complete introduction and overview to the rapidly expanding field of extrasolar planets and brown dwarfs. The following topics are covered: observational techniques, surveys, studies of individual objects, theoretical properties of low-mass stars, brown dwarfs and giant planets, the contribution of these objects to the Galactic mass-budget, processes that lead to formation of planets versus white dwarfs, implication of such objects for the occurrence of Earth-like planets, and future prospects in the field. The book enables readers to gain a solid scientific background in all the essential aspects of this exciting new area of astronomical research.
A Search for Pulsation in Young Brown Dwarfs and Very Low Mass Stars
Author: Ann Marie Cody
Publisher: Universal-Publishers
Published: 2013-08
Total Pages: 318
ISBN-13: 1612334210
DOWNLOAD EBOOK →In 2005, Palla & Baraffe proposed that brown dwarfs and very low mass stars (
A Giant Step: From Milli- to Micro- Arcsecond Astrometry (IAU S248)
Author: International Astronomical Union. Symposium
Publisher: Cambridge University Press
Published: 2008-08-21
Total Pages: 620
ISBN-13: 9780521874700
DOWNLOAD EBOOK →State-of-the-art review of the growing field of astrometry, for researchers and graduate students.
Ultracool Dwarfs
Author: Hugh R.A. Jones
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 199
ISBN-13: 3642566723
DOWNLOAD EBOOK →Once you have looked at the night sky on a moonless night it is not hard to realise why so much of our science and religion has its roots in the stars. Yet it took until 1850 to realise that fainter stars were not necessarily further away, nor the brighter ones closer. In fact within the magnitude range observable to the naked eye it is probable that the brighter star is in fact further away. Even today the measurement of stellar distances is relatively difficult and is gener ally only done using dedicated telescopes. In the early years of the 20th century Hertzsprung and Russell developed a powerful classification diagram which al lows stars to be distinguished using a plot of their colour versus magnitude. The construction of this diagram involved the use of spectroscopy which has become the cornerstone of modern astronomy. As telescopes become more powerful, de tectors more sensitive and more physics is added to astrophysics, astronomical spectroscopy becomes a more powerful tool. The concern of this book is the spectral classification of stars. With a single spectrum of a star it is possible to uniquely classify an object and find its place on the Hertzsprung-Russell diagram. This spectrum is thus equivalent to having the colour and the magnitude of the object which can in turn be related to mass and other quantities.
An Introduction to the Theory of Stellar Structure and Evolution
Author: Dina Prialnik
Publisher: Cambridge University Press
Published: 2000-07-24
Total Pages: 284
ISBN-13: 9780521659376
DOWNLOAD EBOOK →Using fundamental physics, the theory of stellar structure and evolution is able to predict how stars are born, how their complex internal structure changes, what nuclear fuel they burn, and what their ultimate fate is - a fading whitedwarf, or a cataclysmic explosion as a supernova, leaving behind a collapsed neutron star or black hole. This lucid textbook provides students with a clear and pedagogical introduction to the theory of stellar structure and evolution. It requires only basic physics and mathematics learnt in first- and second-year undergraduate studies, and assumes no prior knowledge of astronomy. The unique feature of this book is the emphasis throughout on the basic physical principles governing stellar evolution. Exercises and their full solutions are included to help students test their understanding. This textbook provides a stimulating introduction for undergraduates in astronomy, physics, planetary science and applied mathematics taking a course on the physics of stars.
