M dwarfs in the Galactic halo

  • I. Neill Reid
  • Suzanne L. Hawley
Part of the Astronomy and Planetary Sciences book series (PRAXIS)


Approximately 99.7% of the stars in the immediate vicinity of the Sun are members of the Galactic disk. The remaining stars belong to the Galactic halo — the fossil remnants of the first extensive burst of star formation in the history of the Galaxy (see Chapter 6). A clear distinction should be drawn between the stellar halo population — made of baryonic material and having a total mass of only ~109 M — and the dark-matter halo, which is believed to be the dominant contributor to the Galactic potential. The dark-matter halo is held responsible for the relatively flat Galactic rotation curve, but its constituents have not yet been identified; those are the targets of gravitational lensing surveys. The present chapter concentrates on the stellar halo, and illustrates how observations of the lower-mass halo subdwarfs provide insight into the structure of the oldest stellar population so far identified in the Galaxy. The nature of the dark-matter halo is a subject in itself, and recent investigations are summarised elsewhere [T1].


Mass Function White Dwarf Globular Cluster Proper Motion Luminosity Function 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • I. Neill Reid
    • 1
  • Suzanne L. Hawley
    • 2
  1. 1.Formerly of Edinburgh UniversityEdinburghScotland
  2. 2.Department of Physics and AstronomyMichigan State UniversityEast LansingUSA

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