J/AJ/126/472 High proper motion stars in USNO-B (Gould, 2003)
Completeness of USNO-B for high proper motion stars.
Gould A.
<Astron. J. 126, 472 (2003)>
=2003AJ....126..472G 2003AJ....126..472G
ADC_Keywords: Proper motions
Keywords: astrometry - methods: statistical
Abstract:
The completeness of USNO-B detections of high proper motion
(µ>180mas/yr) stars is tested, and the accuracy of its measurements
is compared to the revised New Luyten Two-Tenths catalog of Salim &
Gould (2002ApJ...575L..83S 2002ApJ...575L..83S). For 14.5<V<18.5, only 6% of such stars
are missing from USNO-B (Cat. I/284), while another 3% have large
errors, mostly too large to be useful. Including both classes,
incompleteness is 9%. These fractions rise toward both brighter and
fainter magnitudes. Incompleteness rises with proper motion to 30% at
µ=1"/yr. It also rises to 35% at the Galactic plane, although this
is only determined for relatively bright stars V≲14. For binaries,
incompleteness rises from 9% at separations of 30" to 47% at 10". The
proper-motion errors reported internally by USNO-B are generally
correct. However, there is a value of σµ∼4mas/yr below which
the reported errors should not be taken at face value. The small
number of stars with relatively large reported errors
(σµ≳20mas/yr) may actually have still larger errors than
tabulated.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 101 1092 Binary Sample
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See also:
I/284 : The USNO-B1.0 Catalog (Monet+ 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- 5 I5 --- NLTT The NLTT (Cat. I/98) number
7- 8 I2 --- UCode The USNO-B (Cat. I/284) validity code (1)
10- 18 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
20- 28 F9.5 deg DEdeg Declination in decimal degrees (J2000)
30- 36 F7.4 arcsec/yr pmRA The revised NLTT (Cat. J/ApJ/582/1011)
right ascension proper motion
38- 44 F7.4 arcsec/yr pmDE The revised NLTT declination proper motion
46- 51 F6.3 arcsec/yr pmRAU The USNO-B right ascension proper motion
53- 58 F6.3 arcsec/yr pmDEU The USNO-B declination proper motion
60- 64 F5.2 mag Vmag The revised NLTT V-band magnitude
66- 70 F5.2 mag V-J The revised NLTT (V-J) color
72- 74 I3 --- NCode The revised NLTT source code (2)
76- 81 F6.1 arcsec NSep ? NLTT notes binary separation (3)
83- 87 F5.1 deg NPA ? NLTT notes binary position angle (3)
89- 94 F6.1 arcsec rNSep ? Revised NLTT position binary separation (3)
96-100 F5.1 deg rNPA ? Revised NLTT position binary position
angle (3)
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Note (1): USNO-B validity code as follows:
-1 = Not used
0 = Not in USNO-B
1 = Bad USNO-B proper motion with USNO-B companion
2 = Bad USNO-B proper motion without USNO-B companion
3 = Good USNO-B proper motion
Note (2): Revised NLTT source code as follows:
555 = Identified in USNO-A (Cat. I/252) and 2MASS (Cat. II/246)
576 = Identified in 2MASS (Cat. II/246) as an NLTT
(Cat. J/ApJ/582/1011) common proper motion companion to
another revised NLTT star
566 = Identified in 2MASS (Cat. II/246) only based on the predicted
NLTT (Cat. J/ApJ/582/1011) position
222 = Identified in Tycho-2 (Cat. I/259)
121 = Identified in Hipparcos (Cat. I/239) and Tycho-2 (Cat. I/259)
111 = Identified in Hipparcos (Cat. I/239)
Note (3): Revised NLTT position binary position angle of second component
relative to the first.
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History:
From electronic version of the journal
23-Aug-2005 : An inversion between pmRA and pmDE for the pairs
(line 927 to the end) was corrected.
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 27-Aug-2003