New Light on Dark Stars: Red Dwarfs, Low-Mass Stars, Brown DwarfsPerhaps 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. |
Contents
1 | |
OBSERVATIONAL PROPERTIES OF LOWMASS DWARFS | 74 |
THE MASS FUNCTION | 76 |
THE STRUCTURE FORMATION AND EVOLUTION OF LOW | 84 |
1 | 125 |
THE PHOTOSPHERE | 127 |
8 | 134 |
15 | 149 |
A GALACTIC STRUCTURE PRIMER | 209 |
25 | 213 |
29 | 236 |
225 | 250 |
THE STELLAR LUMINOSITY FUNCTION | 252 |
34 | 276 |
wwww | 282 |
BROWN DWARFS | 343 |
Other editions - View all
New Light on Dark Stars: Red Dwarfs, Low-Mass Stars, Brown Stars Neil Reid,Suzanne Hawley Limited preview - 2005 |
New Light on Dark Stars: Red Dwarfs, Low-Mass Stars, Brown Stars Neil Reid,Suzanne Hawley Limited preview - 2006 |
New Light on Dark Stars: Red Dwarfs, Low-Mass Stars, Brown Dwarfs I. Neill Reid,Suzanne L. Hawley No preview available - 2000 |
Common terms and phrases
2MASS 8-parsec absolute magnitude absorption abundance Allard analysis atmosphere atomic binary brown dwarfs calibration Chapter chromospheric colour colour-magnitude companions components continuum convection decreasing density derived detection determined diagram disk dwarfs distance distribution dynamo effective temperature emission energy equation estimate Fe/H Figure flare flux Galactic disk Galaxy Gizis globular clusters H-R diagram halo Hauschildt Hipparcos Hyades hydrogen hydrogen-burning infrared kinematics L dwarfs late-type low-mass dwarfs low-mass stars luminosity function magnetic activity magnetic field main sequence main-sequence mass function measured metal-poor metallicity MNRAS models molecular near-infrared objects observations opacity open clusters optical orbits parallax parsecs photometric photosphere plane Pleiades plotted population predicted proper-motion radiation radiative radii radius regions Reid relationship rotation sample shows solar spectral type spectroscopic spectrum star formation star-formation stellar structure subdwarfs surveys Teff telescope theoretical velocity dispersion wavelengths white dwarf X-ray