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J/AJ/103/638        USNO Photographic Parallaxes. I.         (Monet+, 1992)

US Naval Observatory CCD parallaxes of faint stars. I. Program description and first results. Monet D.G., Dahn C.C., Vrba F.J., Harris H.C., Pier J.R., Luginbuhl C.B., Ables H.D. <Astron. J. 103, 638 (1992)> =1992AJ....103..638M
ADC_Keywords: Stars, faint ; Parallaxes, trigonometric ; Photometry ; Proper motions Abstract: The U.S. Naval Observatory CCD trigonometric parallax program is described in detail, including the instrumentation employed, observing procedures followed, and reduction procedures applied. Astrometric results are presented for 72 stars ranging in apparent brightness from V=15.16 to 19.58. Photometry (V and V-I on the Kron-Cousins system) is presented for the parallax stars and for all 426 individual reference stars employed in the astrometric solutions. Corrections for differential color refraction, calibrated to the observed V-I colors, have been applied to all astrometric measures. The mean errors in the relative parallaxes range from ±0.0005" to ±0.0027" with a median value of ±0.0010". Seventeen of the 23 stars with Vtan>200km/s form a well-delineated sequence of extreme subdwarfs covering 11.5<MV<14.5 in the MV vs V-I diagram. The transformation to the Mbol vs log Teff plane is presented and the results are compared with various model interior computations. Within the limitations due to the uncertain Teff scale for cool dwarfs and subdwarfs, the coolest members of the extreme subdwarf sequence appear to be near the hydrogen-burning minimum mass limit for stars with metallicities of [M/H]~-2. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 136 72 Astrometric and photometric results notes.dat 80 228 Individual notes
See also: I/87 : LHS Catalogue, 2nd Edition (Luyten 1979) J/AJ/105/1571 : USNO Photographic Parallaxes. IX (Harrington+ 1993) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 2 I2 --- USNO Sequential number 3 A1 --- Note [n] note detailed in notes.dat file 5- 9 A5 --- LHS ? LHS (Luyten, 1979, Cat. I/87) number 11 A1 --- n_Name [*] *: observations are continuing (Sect. 6) 13- 21 A9 --- Name Name 23- 24 I2 h RAh Right ascension (1950) 26- 27 I2 min RAm Right ascension (1950) 29- 30 I2 s RAs Right ascension (1950) 32 A1 --- DE- Declination sign (1950) 33- 34 I2 deg DEd Declination (1950) 36- 39 F4.1 arcmin DEm Declination (1950) 41- 43 I3 --- Nf Number of CCD frames employed in the solution 44 A1 --- --- [,] 45- 46 I2 --- Nn Number of separate nights on which the frame were taken 47 A1 --- --- [,] 48- 49 I2 --- Ns Number of reference stars employed in the solution 51- 55 F5.1 mas plxr Relative trigonometric parallax 57- 59 F3.1 mas e_plxr rms uncertainty on plxr 61- 66 F6.1 mas/yr pm Total relative proper motion 68- 70 F3.1 mas/yr e_pm rms uncertainty on mu 72- 77 F6.2 deg pmPA Relative position angle of the total proper motion (measured north to east) 79- 82 F4.2 mas e_pmPA rms uncertainty on pmPA 84- 88 F5.2 mag Vmag V magnitude in the Kron-Cousins system 90- 93 F4.2 mag V-I V-I colour index in the Kron-Cousins system 95- 99 F5.1 mas plx Absolute trigonometric parallax 101-103 F3.1 mas e_plx rms uncertainty on plx 105-109 F5.2 mag VMAG Absolute V magnitude 111-114 F4.2 mag e_VMAG rms uncertainty on VMAG 116-120 F5.1 km/s Vtan Tangential velocity 122-126 F5.1 km/s e_Vtan rms uncertainty on Vtan 128-131 F4.1 yr DT1 Date of the first frame employed (1900+) 132 A1 --- --- [-] 133-136 F4.1 yr DT2 Date of the last frame employed (1900+)
Byte-by-byte Description of file: notes.dat
Bytes Format Units Label Explanations
1- 2 I2 --- USNO USNO number 4- 80 A77 --- Text Text of the note
History: Prepared via OCR at CDS. References: Riddle First catalog 1970PUSNO..20c...1R Routly Second catalog 1972PUSNO..20f...1R Harrington et al., Third catalog 1975PUSNO..24a...1H Dahn et al., Fourth catalog 1976PUSNO..24c...1D Harrington & Dahn Paper V 1980AJ.....85..454H Dahn et al., Paper VI 1982AJ.....87..419D Harrington et al., Paper VII 1985AJ.....90..123H Dahn et al., Paper VII 1988AJ.....95..237D Harrington et al., Paper IX 1993AJ....105.1571H, Cat. J/AJ/105/1571
(End) James Marcout, Patricia Bauer [CDS] 01-Dec-2000
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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