J/AJ/113/806 M-Subdwarfs (Gizis 1997)
M-Subdwarfs: Spectroscopic Classification and the Metallicity Scale
Gizis J.E.
<Astron. J., 113, 806 (1997)>
=1997AJ....113..806G 1997AJ....113..806G
ADC_Keywords: Stars, M-type; Spectroscopy; Radial velocities;
Stars, population II; Stars, subdwarf; Photometry
Description:
We present a spectroscopic classification system for M-dwarfs and
M-subdwarfs based on quantitative measures of TiO and CaH features
in the region 6200 - 7400 Angstroms. Our sample of cool stars covers
the range from solar metallicity stars to the most extreme subdwarfs
known. Using synthetic spectra computed by Allard and Hauschildt (1995),
we derive metallicities for the stars. Stars are classified
as dwarfs (M V), subdwarfs (sdM), or extreme subdwarfs (esdM).
These classifications correspond to [m/H] = 0.0, -1.2, and
-2.0 respectively. Our metallicity scale agrees with theoretical HR
diagrams and HST globular cluster measurements. We discuss some nearby
subdwarfs of particular interest in light of our metallicity scale.
We include photometry compiled from the literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 79 Spectroscopic observations (table 2)
table4.dat 70 91 Photometry (table 4)
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See also:
III/198 : PMSU (Palomar/MSU nearby star spectroscopic survey; Hawley+ 1997)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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2- 6 A5 --- LHS *Number in LHS catalog
8- 21 A14 --- Name *Other name
23- 27 F5.3 --- TiO5 TiO5 index: F(7126-7135)/F(7042-7046)
29- 33 F5.3 --- CaH1 CaH1 index: F(6380-6390)/F
(6345-6355,6410-6420))
35- 39 F5.3 --- CaH2 CaH2 index: F(6814-6846)/F(7042-7046)
41- 45 F5.3 --- CaH3 CaH3 index: F(6960-6990)/F(7042-7046)
47- 52 F6.1 km/s RV *Radial Velocity
54- 60 A7 --- Sp Spectral type
62- 65 A4 --- code *Telescope code
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Note on LHS, Name:
Gl - Gliese (1969, Veroff. Astr. Rechen-Instituts, Heidelberg, Nr. 22)
GJ - Gliese & Jahreiss =1979A&AS...38..423G 1979A&AS...38..423G
Wo - Woolley et al (1970, R. Obs. Ann., No. 5) =Cat. V/32
LHS - Luyten Half-Second Catalogue =Cat. I/87
LP - Luyten Palomar proper-motion catalogue
G - Giclas et al (1971, Lowell Proper Motion Survey) =Cat. I/79
Sm - Smethers, see Reid (1982, MNRAS, 201, 51)
TVLM - Tinney Very Low Mass, see Tinney et al. (1995AJ....110.3014T 1995AJ....110.3014T)
Note on RV:
Radial velocity for LHS 2715 has been deleted; it was incorrect.
Note on code:
Source of spectroscopic data:
60 - Palomar 60-in. telescope
100 - Las Campanas 100-in. telescope
200 - Hale 200-in. (Palomar) telescope
200a - Hale 200-in. (Palomar) telescope, August 1995 setup
RHG - Taken from Reid et al. (1995AJ....110.1838R 1995AJ....110.1838R)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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2- 6 A5 --- LHS Number in LHS catalog
8- 12 F5.2 mag V Apparent V magnitude
14- 17 F4.2 mag B-V ? B-V color
19- 22 F4.2 mag V-R ? V-R (Cousins) color
24- 27 F4.2 mag R-I ? R-I (Cousins) color
29- 32 F4.2 mag V-I ? V-I (Cousins) color
34- 39 F6.4 arcsec Plx ? Trigonometric parallax
41- 46 F6.4 arcsec e_Plx ? Uncertainty σ of parallax
49- 53 F5.2 mag DeltaLK *? Lutz-Kelker correction
55- 59 F5.2 mag MV *? Absolute V magnitude
61- 70 A10 --- ref *Source of parallax and photometry
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Note on DeltaLK:
Blank in Lutz-Keller correction indicates a null.
-9.99 indicates that the Lutz-Kelker correction is undefined but < -0.80,
as symbolized by "L" in the original paper.
Note on MV:
Absolute magnitude of LHS 2497 includes 0.75 magnitude correction
for unresolved companion
Note on ref:
Dr. Jahreiss has brought to our attention the fact that DF89's photometry
of LHS 272 is inconsistent with the results of Doyle and Butler
(1990A&A...235..335D 1990A&A...235..335D), Eggen, and Weis. Our comparison of the spectrum
to other subdwarfs suggests that DF89's photometry is too red; thus,
we adopt the other photometry for this electronic version.
References for the trigonometric parallaxes and photometry are:
B - Bessell (1990A&AS...83..357B 1990A&AS...83..357B)
CNS3 - Gliese and Jahreiss (1991, ADC Cat. 5070)
DF89 - Dawson and Forbes (1989PASP..101..614D 1989PASP..101..614D)
DF92 - Dawson and Forbes (1992AJ....103.2063D 1992AJ....103.2063D)
E79 - Eggen (1979ApJS...39...89E 1979ApJS...39...89E)
E87 - Eggen (1987AJ.....93..379E 1987AJ.....93..379E)
HD - Harrington and Dahn (1980AJ.....85..454H 1980AJ.....85..454H)
L - Leggett (1992ApJS...82..351L 1992ApJS...82..351L)
M92 - Monet et al. (1992AJ....103..638M 1992AJ....103..638M)
R - Ryan (1992AJ....104.1144R 1992AJ....104.1144R)
RA - Ruiz and Anguita (1993AJ....105..614R 1993AJ....105..614R)
S - SIMBAD
T - Tinney et al. (1995AJ....110.3014T 1995AJ....110.3014T)
W84 - Weis (1984ApJS...55..289W 1984ApJS...55..289W)
W88 - Weis (1988AJ.....96.1710W 1988AJ.....96.1710W)
W91 - Weis (1991AJ....101.1882W 1991AJ....101.1882W)
WU - Weis and Upgren (1982PASP...94..821W 1982PASP...94..821W)
Y - Van Altena et al. (1991)
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References:
Bessell, 1990, Astron. Astrophys. Suppl. 83, 357. (1990A&AS...83..357B 1990A&AS...83..357B)
Dawson & Forbes, 1992, Astron. J. 103, 2063. (1992AJ....103.2063D 1992AJ....103.2063D)
Dawson & Forbes, 1989, Pub. Astron. Soc. Pac. 101, 614. (1989PASP..101..614D 1989PASP..101..614D)
Doyle and Butler, 1990, Astron. Astrophys. 235, 335. (1990A&A...235..335D 1990A&A...235..335D)
Eggen, 1979, Astrophys. J. Suppl. 39, 89. (1979ApJS...39...89E 1979ApJS...39...89E)
Eggen, 1987, Astron. J. 92, 379. (1987AJ.....93..379E 1987AJ.....93..379E)
Giclas et al., 1971, Lowell Proper Motion Survey (Flagstaff, AZ:
Lowell Obs.). ADC Cat. 1079.
Gliese & Jahreiss, 1991, Preliminary Version of the Third Catalog of
Nearby Stars (CNS3), ADC Cat. 5070
Gliese, 1969, Veroff. Astr. Rechen-Instituts, Heidelberg, Nr. 22.
Gliese & Jahreiss, 1979, Astron. Astrophys. Suppl., 38, 423.
(1979A&AS...38..423G 1979A&AS...38..423G)
Gizis, 1997, Astron. J., 113, 806 (1997AJ....113..806G 1997AJ....113..806G)
Harrington & Dahn, 1980, Astron. J. 85, 454. (1980AJ.....85..454H 1980AJ.....85..454H)
Leggett, 1992, Astrophys. J. Suppl. 82, 351. (1992ApJS...82..351L 1992ApJS...82..351L)
Luyten, 1979, Catalogue of stars with proper motions exceeding 0.5
arcsec annually (Minneapolis: U Minnesota). ADC Cat. 1098
Monet et al., 1992, Astron. J. 103, 638. (1992AJ....103..638M 1992AJ....103..638M)
Reid, 1982, Mon. Not. R. Astron. Soc. 201, 51. (1982MNRAS.201...51R 1982MNRAS.201...51R)
Reid et al., 1995, Astron. J. 110, 1838. (1995AJ....110.1838R 1995AJ....110.1838R)
Ruiz & Anguita, 1993, Astron. J. 105, 614. (1993AJ....105..614R 1993AJ....105..614R)
Ryan, 1992, Astron. J. 104, 1144. (1992AJ....104.1144R 1992AJ....104.1144R)
Tinney et al., 1995, Astron. J. 110, 3014. (1995AJ....110.3014T 1995AJ....110.3014T)
Van Altena et al., 1991, General Catalog of Trigonometric Stellar
Parallaxes: Preliminary Version. (See ADC Cat. 1238)
Weiss, 1984, Astrophys. J. Suppl. 55, 289. (1984ApJS...55..289W 1984ApJS...55..289W)
Weiss, 1988, Astron. J. 96, 171. (1988AJ.....96.1710W 1988AJ.....96.1710W)
Weiss, 1991, Astron. J. 101, 1882. (1991AJ....101.1882W 1991AJ....101.1882W)
Weis & Upgren, 1982, Pub. Astron. Soc. Pac. 94, 821. (1982PASP...94..821W 1982PASP...94..821W)
Woolley et al., 1970, R. Obs. Ann., No. 5. ADC Cat. 5032.
(End) John Gizis [U.Mass] 15-Dec-1997