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
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). 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:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 101 1092 Binary Sample
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
Bytes Format Units Label Explanations
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)
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.
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
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