/ftp/cats/J_other/ARA+A/43.195



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J/other/ARA+A/43.195   New spectral types L and T            (Kirkpatrick, 2005)
The following files can be converted to FITS (extension .fit .fgz or .fiZ)
	table3.dat refs.dat
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Query from: http://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/other/ARA+A/43.195
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drwxr-xr-x 4 cats archive 102 Jul 26 2011 [Up] drwxr-xr-x 2 cats archive 312 Jan 13 2023 [TAR file] -rw-r--r-- 1 cats archive 487 Dec 19 2022 .message -r--r--r-- 1 cats archive 7179 Jan 31 2007 ReadMe -rw-r--r-- 1 cats archive 412 Sep 19 2007 +footg5.gif -rw-r--r-- 1 cats archive 3132 Mar 5 2008 +footg8.gif -r--r--r-- 1 cats archive 1062 Aug 12 2006 refs.dat [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 9321 Jan 31 2007 table3.dat [txt] [txt.gz] [fits] [fits.gz] [html]
Beginning of ReadMe : J/other/ARA+A/43.195 L and T dwarf stars (Kirkpatrick, 2005) ================================================================================ New spectral types L and T. Kirkpatrick J.D. <Annual Rev. Astron. Astrophys., 43, 195 (2005)> =2005ARA&A..43..195K ================================================================================ ADC_Keywords: Stars, dwarfs ; Parallaxes, trigonometric ; MK spectral classification Abstract: 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 catalogued. This review concentrates on the spectroscopic properties of these objects, beginning with the establishment of classification schemes rooted in the MK Process. The resulting grid of spectral types is then used as a tool to ferret out the underlying physics. The temperature ranges covered by these spectral types, the complex chemical processes responsible for the shape of their emergent spectra, their nature as either true stars or brown dwarfs, and their number density in the Galaxy are discussed. Two promising avenues for future research are also explored: the extension of the classification system to three dimensions to account for gravity- and metallicity-dependent features, and the capability of newer large-area surveys to uncover brown dwarfs cooler than those now recognized.