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 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.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 150 70 L and T Dwarfs with Measured Trigonometric
Parallaxes
refs.dat 98 22 References
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)
J/ApJ/564/421 : Spectra of T dwarfs. I. (Burgasser+, 2002)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 27 A27 --- Name IR name
29- 30 I2 h RAh Right ascension (J2000) (1)
32- 33 I2 min RAm Right ascension (J2000) (1)
35- 39 F5.2 s RAs Right ascension (J2000) (1)
41 A1 --- DE- Declination sign (J2000) (1)
42- 43 I2 deg DEd Declination (J2000) (1)
45- 46 I2 arcmin DEm Declination (J2000) (1)
48- 51 F4.1 arcsec DEs Declination (J2000) (1)
53- 58 F6.2 mas plx Trigonometric parallax (2)
60- 64 F5.2 mas e_plx rms uncertainty on plx
65- 66 I2 --- r_plx Reference for plx
68- 72 F5.2 mag Jmag J magnitude (3)
74- 77 F4.2 mag e_Jmag rms uncertainty on Jmag
79- 80 I2 --- r_Jmag Reference for Jmag
82- 86 F5.2 mag JMAG Absolute J magnitude (3)
88- 91 F4.2 mag e_JMAG rms uncertainty on JMAG
93- 96 F4.2 mag dJmag ?=- ΔJ for binaries (3)
98-101 I4 K TG04 ?=- Temperature from Golimowski et al.,
2004AJ....127.3516G 2004AJ....127.3516G
103-106 I4 K TV04 ?=- Temperature from Vrba et al.,
2004AJ....127.2948V 2004AJ....127.2948V
108-111 I4 K TD02 ?=- Temperature from Dahn et al.,
2002AJ....124.1170D 2002AJ....124.1170D
113-117 A5 --- SpType0 Optical spectral type (6)
118-119 I2 --- r_SpType0 ? Reference for SpType0
121-130 A10 --- SpType1 Infrared spectral type (6)
132-133 I2 --- r_SpType1 ? Reference for SpType1
134-140 A7 --- SpType2 IR spectral type by Burgasser et al., 2002,
Cat. J/ApJ/564/421
141-150 A10 --- OName Other name
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Note (1): Positions derived from IR name
Note (2): All trigonometric parallaxes are given as Piabs except for
those of Tinney et al. (2003AJ....126..975T 2003AJ....126..975T), which are Pirel.
Note (3): In the case of close binaries, the absolute J magnitudes listed
above include the contribution of both components. Using available
photometry from high-resolution imaging, the JMAG values of the
individual components can be measured. The temperatures listed in
the table are those of the primary, so it is the JMAG value for
the primary that is used in Figure 8. The known binaries, and the
ΔJ values used to correct the joint magnitudes to those of
the primary alone, are given in the "dJmag" column; See Tinney et
al. (2003AJ....126..975T 2003AJ....126..975T), Vrba et al. (2004AJ....127.2948V 2004AJ....127.2948V), and
Volk et al. (2003IAUC.8188....2V 2003IAUC.8188....2V) for details. Bouy et al. (2003,
Cat. J/AJ/126/1526) also claim that 2MASS J1112+3548 (Gl 417B)
is a 0.07" double with Δmag≫1.0mag at 1um; this object, like
2MASS J1534-2952 and ε Ind B, is not included in Figure 8
because Vrba et al. (2004AJ....127.2948V 2004AJ....127.2948V) do not calculate a
temperature for it.
Note (6): Errors on spectral types are ≤±0.5 subtype for all except those
indicated explicitly. Except where noted, optical types are from
Kirkpatrick et al. (1999ApJ...519..802K 1999ApJ...519..802K, 2000AJ....120..447K 2000AJ....120..447K), or
Burgasser et al. (2003AJ....125..850B 2003AJ....125..850B) and near-infrared types are
from Geballe et al. (2002ApJ...564..466G 2002ApJ...564..466G) or Knapp et al. (2004 ,
Cat. J/AJ/127/3553).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode BibCode
24- 48 A25 --- Aut Author's name
50- 98 A49 --- Com Comments
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History:
* 13-Jun-2006: From electronic version of the journal
* 31-Jan-2007: table3, record#2:
Name 2MASW J003030-145033 changed into 2MASW J0030300-145033
(End) Patricia Vannier [CDS] 13-Jun-2006