J/A+A/442/211 Spectroscopic distances of 322 NLTT stars (Scholz+, 2005)
Search for nearby stars among proper motion stars selected by
optical-to-infrared photometry. III. Spectroscopic distances of 322 NLTT stars.
Scholz R.-D., Meusinger H., Jahreiss H.
<Astron. Astrophys., 442, 211-227 (2005)>
=2005A&A...442..211S 2005A&A...442..211S
ADC_Keywords: Surveys ; Stars, nearby ; Stars, pre-main sequence ;
MK spectral classification ; Stars, distances
Keywords: techniques: spectroscopic - surveys - astrometry - stars: distances -
stars: late-type - Solar neighbourhood
Abstract:
Distance estimates based on low-resolution spectroscopy and Two Micron
All Sky Survey (2MASS, Cat. II/246) J magnitudes are presented for
322 nearby candidates from Luyten's NLTT catalogue (I/98). Mainly
relatively bright (typically 7<Ks<11) and red high proper motion stars
have been selected according to their 2MASS magnitudes and
optical-to-infrared colours (+1<R-Ks<+7). Some LHS stars previously
lacking spectroscopy have also been included. We have classified the
majority of the objects as early-M dwarfs (M2-M5). More than 70% of
our targets turned out to lie within the 25pc horizon of the catalogue
of nearby stars, with 50 objects placed within 15pc and 8 objects
being closer than 10pc. Three objects in the 10pc sample have no
previously published spectral type: LP 876-10 (M4), LP 870-65 (M4.5),
and LP 869-26 (M5). A large fraction of the objects in our sample
(57%) ave independent distance estimates, mainly by the recent efforts
of Reid and collaborators. Our distance determinations are generally
in good agreement with theirs. 11 rather distant (d>100pc) objects
have also been identified, including a probable halo, but relatively
hot (Teff=13000K) white dwarf (LHS 1200) and 10 red dwarfs with
extremely large tangential velocities (250<vt<1150km/s). Altogether,
there are 11 red dwarfs (including one within 70pc) with tangential
velocities larger than about 250km/s. All these objects are suspected
to be in fact subdwarfs, if so, their distances would be only about
half of our original estimates. The three most extreme objects in that
respect are the K and early M dwarfs LP 323-168, LHS 5343 and
LP 552-21 with corrected distances between 180pc and 400pc and
resulting tangential velocities still larger than about 400km/s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 104 322 Data of the 322 stars of the sample.
notes.dat 79 85 Individual notes
refs.dat 69 26 References
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/98 : NLTT Catalogue (Luyten, 1979)
J/ApJ/582/1011 : Revised NLTT Catalog (Salim+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name NLTT, LHS, Giclas or Durchmusterung name
11 A1 --- n_Name [*] * indicates a note in notes.dat
13- 14 I2 h RAh Right Ascension J2000 (hours) (2MASS)
16- 17 I2 min RAm Right Ascension J2000 (minutes) (2MASS)
19- 23 F5.2 s RAs Right Ascension J2000 (seconds) (2MASS)
26 A1 --- DE- Declination J2000 (sign) (2MASS)
28- 29 I2 deg DEd Declination J2000 (degrees) (2MASS)
31- 32 I2 arcmin DEm Declination J2000 (minutes) (2MASS)
34- 37 F4.1 arcsec DEs Declination J2000 (seconds) (2MASS)
39- 46 F8.3 yr Epoch Epoch of position (2MASS)
48- 53 F6.3 mag Jmag ? J magnitude from 2MASS
55- 60 F6.3 mag Hmag ? H magnitude from 2MASS
62- 67 F6.3 mag Ksmag ? K_s magnitude from 2MASS
69- 71 A3 --- pSp Previous spectral type, G, K, M
72- 74 F3.1 --- pSpC ? Previous spectral sub-class (0.0-9.5)
76- 77 I2 --- r_pSpC ? Reference for pSp and pSpC
79- 83 F5.1 pc pDist ? Previous distance estimate
85- 86 I2 --- r_pDist ? Reference for previous distance estimate
88- 90 A3 --- SpT New spectral type, M, K,WD ,CWD
91- 93 F3.1 --- SpC ? New spectral sub-class (0.0-9.5)
95- 99 F5.1 pc Dist New distance estimate, accurate to ∼20%
101-104 I4 km/s Vt Tangential velocity
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Table 3: Suspected subdwarfs with corrected distances and tangential velocities
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Name SpTypecorr Distcorr Vtcorr
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LP 552-21 sd: M0.5 348 567
LHS 5343 sd: K7.0 187 444
LHS 299 sd: M0.0 75 397
LP 323-168 sd: K2.0 398 394
LHS 2763 sd: M0.0 82 309
LHS 6124 sd: K7.0 121 252
LHS 6147 sd: K7.0 116 231
LHS 6385 sd: K5.0 61 136
LHS 2048 sd: M2.5 52 131
LHS 6356 sd: K5.0 63 127
LHS 3473 sd: M3.0 33 124
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Name
11- 80 A70 --- Note Text of the note
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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- 42 A19 --- Aut Author's name
46- 75 A30 --- Com Comments
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Acknowledgements: Ralf-Dieter Scholz, rdscholz(at)aip.de
(End) Patricia Vannier [CDS] 20-Oct-2005