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J/AJ/90/2089          Stars of very low metal abundance. I (Beers+, 1985)

A search for stars of very low metal abudance. I Beers T.C., Preston G.W., Shectman S.A. <Astron. J. 90, 2089 (1985)> =1985AJ.....90.2089B
ADC_Keywords: Stars, metal-deficient ; Stars, halo ; Spectroscopy Description: An objective-prism and a narrowband interference filter have been used in combination on the Curtis Schmidt telescope at CTIO to conduct a search for extremely metal-poor stars. The filter restricts the bandpass to the region around the H and K lines of CaII; the metal-poor candidates are those stars with weak or absent H and K. Slit spectra (1 A resolution) of some 450 candidates are used to measure equivalent widths of the CaII K line and Balmer features. A calibration of the K-line strength for giants in the metal-poor globular cluster NGC 6397 and field dwarfs and giants of known metallicity is used to identify survey candidates with metal abundance [Fe/H]≤-2.0; a list of 134 such stars is presented. UBV photometry is used to distinguish between two groups of metal-poor stars: a group with objects near the main-sequence turnoff, on the subgiant branch, and on the giant branch; and a second group with objects on the red horizontal branch (RHB) and asymptotic giant branch (AGB). The RHB-AGB stars exhibit the well-known weak G-band effect; three CH-strong objects are identified among the subgiants. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 44 72 Objective-prism survey plate log. table3.dat 30 13 Velocities of standard stars table4.dat 67 32 Standard-star line indices table5.dat 116 134 Metal-poor stars
See also: J/AJ/87/1515 : UBV photometry of AB stars in halo (Pier, 1982) J/ApJS/53/791 : Spectroscopy of AB stars in halo (Pier, 1983) J/PASP/102/1392 : UBV photometry from HK survey. (Doinidis+ 1990) J/PASP/103/973 : Photoelectric UBV from HK survey. (Doidinis+ 1991) J/ApJS/76/1001 : UBV photometry of HK survey stars (Preston+, 1991) J/AJ/103/267 : Spectrocopy of hot stars in galactic halo (Beers+ 1992) J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992) J/AJ/108/268 : HK survey emission-line candidates positions (Beers+ 1994) J/AJ/108/538 : Metal-poor MS stars UBV photometry (Preston+ 1994) J/AJ/112/1188 : HK survey emission-line candidates (Beers+ 1996) J/AJ/117/2329 : Spectroscopy of hot stars in the halo. (Wilhelm+, 1999) J/ApJS/123/639 : UBV photometry of metal-weak candidates (Norris+, 1999) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
2- 6 I5 --- BPS-CS Plate number (Curtis Schmidt) 16- 17 I2 h RAh Right ascension (1950) 19- 22 F4.1 min RAm Right ascension (1950) 24 A1 --- DE- Declination sign 25- 26 I2 deg DEd Declination (1950) 28- 29 I2 arcmin DEm Declination (1950) 32- 36 F5.1 deg GLON Galactic longitude 39- 43 F5.1 deg GLAT Galactic latitude
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 10 A10 --- Star Star 13- 16 I4 km/s RVcat Radial velocity from Carney (1981ApJ...245..238C) 19- 22 I4 km/s RVobs Observed radial velocity 24- 25 I2 km/s e_RVobs Error on radial velocity 28- 30 I3 km/s DRV Difference between the observed and taken from literature radial velocity
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 13 A13 --- Star Star name 17- 20 F4.2 0.1nm EW(K) CaII K-line index (G1) 23- 25 F3.2 0.1nm e_EW(K) ? Error on K index 28- 31 F4.2 0.1nm EW(H') H' line index (G1) 34- 36 F3.2 0.1nm e_EW(H') ? Error on H' 39- 42 F4.2 0.1nm EW(G) G-band line index (G1) 45- 47 F3.2 0.1nm e_EW(G) ? Error on G 50- 53 F4.2 mag B-V B-V colour index 55- 58 F4.1 Sun [Fe/H] Metallicity [Fe/H] 61 A1 --- LC [dg] luminosity lass: 'g' (giant) when the star lies above the main-sequence turnoff, 'd' (dwarf) when the star lies below the main-sequence turnoff 64- 67 A4 --- Refs References (2)
Note (2): The references are numbered as follows: 1 = Bessell and Norris 1984ApJ...285..622B 2 = Bond 1970ApJS...22..117B 3 = Cannon 1974MNRAS.167..551C 4 = Carney 1979ApJ...233..211C 5 = Carney 1980AJ.....85...38C 6 = Carney and Peterson 1981ApJ...245..238C 7 = Sneden 1974ApJ...189..493S 8 = Spite and Spite 1978A&A....67...23S 9 = Wallerstein et.al. 1963ApJ...137..280W 10 = Zinn 1980ApJS...42...19Z
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 9 A9 --- BPS-CS Metal poor candidate star name 11- 12 I2 h RAh Right ascension (1950) 14- 15 I2 min RAm Right ascension (1950) 17- 20 F4.1 s RAs Right ascension (1950) 22 A1 --- DE- Declination sign 23- 24 I2 deg DEd Declination (1950) 26- 27 I2 arcmin DEm Declination (1950) 29- 30 I2 arcsec DEs Declination (1950) 32- 36 F5.1 deg GLON Galactic longitude 38- 42 F5.1 deg GLAT Galactic latitude 44- 47 I4 km/s HV Heliocentric velocity 49- 50 I2 km/s e_HV Error on heliocentric velocity 54- 58 F5.2 mag Vmag Johnson V magnitude 61- 64 F4.2 mag B-V Johnson (B-V) color 66- 70 F5.2 mag U-B Johnson (U-B) color 74 I1 --- Nobs Number of photometric observations 76- 79 F4.2 mag E(B-V) ? Assumed reddening 82- 85 F4.2 0.1nm EW(K) CaII K-line index (G1) 87- 90 F4.2 0.1nm e_EW(K) Error on CaII K-line index 92- 95 F4.2 0.1nm EW(H') H' line index (G1) 97-100 F4.2 0.1nm e_EW(H') Error on H' index 101-105 F5.2 0.1nm EW(G) G-band line index (G1) 107-110 F4.2 0.1nm e_EW(G) Error on G-band line index
Global notes: Note (G1): Line-index wavelength bands (Table 2, ranges in Å=0.1nm) ------------------------------------------------------ Line Band Blue sideband Red sideband ------------------------------------------------------ CaII K 3927.7-3939.7 3903.9-3923.9 4008.0-4028.0 Hdelta 4098.8-4104.8 4008.0-4028.0 4144.0-4164.0 G-band 4297.5-4312.5 4247.0-4267.0 4357.0-4377.0 Hgamma 4337.5-4343.5 4247.0-4267.0 4357.0-4377.0 ------------------------------------------------------ H' is defined as 0.5 Hδ + 0.525 Hγ - 0.05 ------------------------------------------------------
References: Beers et al., Paper II, 1992AJ....103.1987B, Cat. J/AJ/103/1987 Norris et al., Paper III, 1999ApJS..123..639N, Cat. J/ApJS/123/639 Anthony-Twarog et al., Paper IV, 2000AJ....119.2882A Bonifacio et al., Paper V, 2000AJ....120.2065B Roederer et al., Paper VI, 2014AJ....147..136R, Cat. J/AJ/147/136 Beers T.C., Preston G.W., Shectman S.A. 1992, Astron. Journal 103, 1987 Bessell M.S., Norris J. 1984, Astrophys. J. 285, 622 Bond H.E. 1970, Astrophys. J. Suppl. 22, 117 Cannon R.D. 1974, MNRAS 167, 551 Carney B.W. 1979, Astrophys. J., 233, 211 Carney B.W. 1980a, Astron. J. 85, 38 Carney B.W. 1980b, "A Catalog of Field Population II Stars" (preprint) Carney B.W., Peterson R.C. 1981, Astrophys. J., 245, 238 Sneden C. 1974, Astrophys. J., 189, 493 Spite M., Spite F. 1978, Astron. Astrophys., 67, 23 Wallerstein G., Greenstein J.L., Parker R., Helfer H.L., Aller L.H. 1963, Astrophys. J., 137, 280 Zinn R.J. 1980, Astrophys. J., Suppl., 42, 19 Historical Notes: Keypunched at CDS
(End) James Marcout, Simona Mei [CDS] 14-Aug-1995
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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