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 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:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 136 72 Astrometric and photometric results
notes.dat 80 228 Individual notes
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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 deg 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+)
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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
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History:
Prepared via OCR at CDS.
References:
Riddle First catalog 1970PUSNO..20c...1R 1970PUSNO..20c...1R
Routly Second catalog 1972PUSNO..20f...1R 1972PUSNO..20f...1R
Harrington et al., Third catalog 1975PUSNO..24a...1H 1975PUSNO..24a...1H
Dahn et al., Fourth catalog 1976PUSNO..24c...1D 1976PUSNO..24c...1D
Harrington & Dahn Paper V 1980AJ.....85..454H 1980AJ.....85..454H
Dahn et al., Paper VI 1982AJ.....87..419D 1982AJ.....87..419D
Harrington et al., Paper VII 1985AJ.....90..123H 1985AJ.....90..123H
Dahn et al., Paper VII 1988AJ.....95..237D 1988AJ.....95..237D
Harrington et al., Paper IX 1993AJ....105.1571H 1993AJ....105.1571H, Cat. J/AJ/105/1571
(End) James Marcout, Patricia Bauer [CDS] 01-Dec-2000