New spectral types L and T

  title={New spectral types L and T},
  author={J. Davy Kirkpatrick},
  journal={Annual Review of Astronomy and Astrophysics},
  • J. Kirkpatrick
  • Published 15 August 2005
  • Physics
  • Annual Review of Astronomy and Astrophysics
The establishment of new spectral classes cooler than type M has had a brief, yet already rich, history. Prototypes of the new "L dwarf" and "T dwarf" classes were first found in the late 1980s to mid-1990s, with a flood of new discoveries occurring in the late 1990s with the advent of deep, large-area, digital sky surveys. Over four hundred and fifty L and T dwarfs are now cataloged. This review concentrates on the spectroscopic properties of these objects, beginning with the establishment of… 
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