The Bottom of the Main Sequence — And Beyond

The Bottom of the Main Sequence — And Beyond

Author: Christopher G. Tinney

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 311

ISBN-13: 3540492178

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The proceedings of this workshop should probably be prefaced with a few words on some of the more confusing jargon. The phrases "Very Low-Mass star" , "VLM star", or simply "VLM" are now used fairly uniformly by as tronomers studying the stars at the bottom of the hydrogen-burning stellar main sequence - unfortunately, however, there is no clear definition as to what constitutes a VLM star. The reader should be warned that VLM stars are variously considered to be stars with; masses less than 0.3M ; masses 0 less than 0.1M ; spectra later than about M6-7; luminosities fainter than 0 Mv = 15; or luminosities fainter than Mbol = 12. The important features of a VLM star, however, would seem to be (1) that it is about as faint as a star can be, and (2) that it still remains a star (ie. it still burns hydrogen) . All of the above criteria, therefore, would seem to qualify an object as a VLM star, and requiring a more stringent definition is probably quibbling.


New Light on Dark Stars

New Light on Dark Stars

Author: Neill I. Reid

Publisher: Springer Science & Business Media

Published: 2013-11-27

Total Pages: 492

ISBN-13: 1447136632

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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.


Very Low-Mass Stars and Brown Dwarfs

Very Low-Mass Stars and Brown Dwarfs

Author: Rafael Rebolo

Publisher: Cambridge University Press

Published: 2000-11-27

Total Pages: 284

ISBN-13: 9780521663359

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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.


Bright Galaxies, Dark Matter, and Beyond

Bright Galaxies, Dark Matter, and Beyond

Author: Ashley Jean Yeager

Publisher: MIT Press

Published: 2021-08-17

Total Pages: 255

ISBN-13: 0262366878

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How Vera Rubin convinced the scientific community that dark matter might exist, persevering despite early dismissals of her work. We now know that the universe is mostly dark, made up of particles and forces that are undetectable even by our most powerful telescopes. The discovery of the possible existence of dark matter and dark energy signaled a Copernican-like revolution in astronomy: not only are we not the center of the universe, neither is the stuff of which we’re made. Astronomer Vera Rubin (1928–2016) played a pivotal role in this discovery. By showing that some astronomical objects seem to defy gravity’s grip, Rubin helped convince the scientific community of the possibility of dark matter. In Bright Galaxies, Dark Matter, and Beyond, Ashley Jean Yeager tells the story of Rubin’s life and work, recounting her persistence despite early dismissals of her work and widespread sexism in science. Yeager describes Rubin’s childhood fascination with stars, her education at Vassar and Cornell, and her marriage to a fellow scientist. At first, Rubin wasn’t taken seriously; she was a rarity, a woman in science, and her findings seemed almost incredible. Some observatories in midcentury America restricted women from using their large telescopes; Rubin was unable to collect her own data until a decade after she had earned her PhD. Still, she continued her groundbreaking work, driving a scientific revolution. She received the National Medal of Science in 1993, but never the Nobel Prize—perhaps overlooked because of her gender. She’s since been memorialized with a ridge on Mars, an asteroid, a galaxy, and most recently, the Vera C. Rubin Observatory—the first national observatory named after a woman.


Ultracool Dwarfs

Ultracool Dwarfs

Author: Hugh R.A. Jones

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 199

ISBN-13: 3642566723

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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.


Planet Quest

Planet Quest

Author: Ken Croswell

Publisher: Oxford University Press, USA

Published: 1999

Total Pages: 348

ISBN-13: 9780192880833

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Are we alone? In 1995 planet hunters discovered the first alien solar system around a star like our own Sun. Ken Croswell tells the fascinating story of this discovery and the people who made it, then explores the possibility that one day we may have the technology to travel to different solar systems and find life.


Dark Side Of The Universe, The: Experimental Efforts And Theoretical Framework - Proceedings Of The Second Workshop

Dark Side Of The Universe, The: Experimental Efforts And Theoretical Framework - Proceedings Of The Second Workshop

Author: Rita Bernabei

Publisher: World Scientific

Published: 1996-10-22

Total Pages: 279

ISBN-13: 9814547077

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The search for dark matter is one of the most relevant topics in astroparticle physics today. It involves many different experimental techniques that should collectively contribute significantly to the identification of the nature and characteristics of the dark matter constituents, offering at the same time much room for new technological developments. The theoretical framework is also essential, both for properly interpreting the different results and for suggesting the most interesting possible candidates and search strategies. This book compares the methods, the developments and the results.


Cosmic Matter

Cosmic Matter

Author: Siegfried Röser

Publisher: John Wiley & Sons

Published: 2008-09-26

Total Pages: 426

ISBN-13: 3527623000

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This 20th volume in the series contains 16 invited reviews and highlight contributions presented during the 2007 International Scientific Conference of the German Astronomical Society on the topic of "Cosmic Matter", held in Würzburg, Germany. The papers published here discuss a wide range of hot topics, including cosmology, high-energy astrophysics, astroparticle physics gravitational waves, extragalactic and stellar astronomy -- together representing the roadmap for astroparticle physics in Europe.


Evolutionary Processes in Binary and Multiple Stars

Evolutionary Processes in Binary and Multiple Stars

Author: Peter Eggleton

Publisher: Cambridge University Press

Published: 2006-07-20

Total Pages: 331

ISBN-13: 1139456954

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Binary systems of stars are as common as single stars. Stars evolve primarily by nuclear reactions in their interiors, but a star with a binary companion can also have its evolution influenced by the companion. Multiple star systems can exist stably for millions of years, but can ultimately become unstable as one star grows in radius until it engulfs another. This volume, first published in 2006, discusses the statistics of binary stars; the evolution of single stars; and several of the most important kinds of interaction between two (and even three or more) stars. Some of the interactions discussed are Roche-lobe overflow, tidal friction, gravitational radiation, magnetic activity driven by rapid rotation, stellar winds, magnetic braking and the influence of a distant third body on a close binary orbit. A series of mathematical appendices gives a concise but full account of the mathematics of these processes.


Beyond the Galaxy

Beyond the Galaxy

Author: Ethan Siegel

Publisher: World Scientific

Published: 2015-11-26

Total Pages: 387

ISBN-13: 981466717X

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"A look up at the night sky reveals a treasury of wonders. Even to the naked eye, the Moon, stars, planets, the Milky Way and even a few star clusters and nebulae illuminate the heavens. For millennia, humans struggled to make sense of what's out there in the Universe, from all we can see to that which lies beyond the limits of even our most powerful telescopes. Beyond the Galaxy traces our journey from an ancient, Earth-centered Universe all the way to our modern, 21st century understanding of the cosmos. Touching on not only what we know but also how we know it, Ethan Siegel takes us to the very frontiers of modern astrophysics and cosmology, from the birth of our Universe to its ultimate fate, and everything in between."--