J/A+A/509/A27 Near-Earth asteroids & QSOs close approaches (Nedelcu+, 2010)
Apparent close approaches between near-Earth asteroids and quasars.
Precise astrometry and frame linking.
Nedelcu D.A., Birlan M., Souchay J., Assafin M., Andrei A.H., Badescu O.,
Popescu P., Paraschiv P.
<Astron. Astrophys. 509, A27 (2010)>
=2010A&A...509A..27N 2010A&A...509A..27N
ADC_Keywords: Minor planets ; Positional data ; Solar system
Keywords: methods: statistical - astrometry - reference systems - ephemerides -
minor planets, asteroids: general
Abstract:
We investigated the link between the International Celestial Reference
Frame (ICRF) and the dynamical reference frame realized by the
ephemerides of the Solar System bodies. We propose a procedure that
implies a selection of events for asteroids with accurately determined
orbits crossing the CCD field containing selected quasars. Using a
Bulirsch-Stoer numerical integrator, we constructed 8-years
(2010-2018) ephemerides for a set of 836 numbered near-Earth asteroids
(NEAs). We searched for close encounters (within a typical field of
view of groundbased telescopes) between our selected set of asteroids
and quasars with high-accuracy astrometric positions extracted from
the Large Quasars Astrometric Catalog (LQAC). In the designated period
(2010-2018), we found a number of 2924, 14257, and 6972 close
approaches (within 10') between asteroids with a minimum solar
elongation value of 60 degrees and quasars from the ICRF-Ext2, the
Very Large Baseline Array Calibrator Survey (VLBA-CS), and the Very
Large Array (VLA), respectively. This large number of close encounters
provides the observational basis needed to investigate the link
between the dynamical reference frame and the ICRF.
Description:
Closest apparent approaches of relatively bright asteroids and quasars
in 2010-2018
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
appulses.dat 111 106 Near Earth Asteroids - Quasars appulses between
2010 and 2018
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See also:
J/AJ/127/3587 : VLBI-Ext2 (Fey+, 2004)
J/ApJS/141/13 : First VLBA calibrator survey: VCS1 catalog (Beasley+, 2002)
J/AJ/126/2562 : Second VLBA calibrator survey: VCS2 (Fomalont+, 2003)
J/AJ/129/1163 : Third VLBA calibrator survey: VCS3 (Petrov+, 2005)
J/AJ/131/1872 : Fourth VLBA calibrator survey: VCS4 (Petrov+, 2006)
J/A+A/494/799 : Large Quasar Astrometric Catalogue (LQAC) (Souchay+, 2009)
Byte-by-byte Description of file: appulses.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Ref [ABC-] Reference flag (1)
5- 19 F15.11 deg RAdeg Right ascension in decimal degrees (J2000) (2)
21- 35 F15.11 deg DEdeg Declination in decimal degrees (J2000) (2)
37- 41 F5.2 mag Umag ?=- Photometric magnitude in Optical U band (2)
43- 47 F5.2 mag Bmag ?=- Photometric magnitude in Optical B band (2)
49- 53 F5.2 mag Vmag ?=- Photometric magnitude in Optical V band (2)
55- 59 F5.2 mag Rmag ?=- Photometric magnitude in Optical R band (2)
61- 65 F5.2 mag Imag ?=- Photometric magnitude in Optical I band (2)
67- 82 A16 --- Date Date of the close approach (YYYY/MM/DD.ddddd)
84- 89 I6 --- Ast The asteroid number
91- 95 F5.2 mag Vast The estimated V magnitude of the asteroid
97-101 F5.2 arcsec Dist The minimum apparent asteroid-quasar distance
103-107 F5.1 deg Sol Solar elongation angle
109-111 I3 --- N* The number of UCAC2 stars in a 10'x10'
field centered at the quasar J2000 position
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Note (1): Quasars flag from LQAC, Cat. J/A+A/494/799:
A = ICRF-Ext2 (Fey et al., Cat. J/AJ/127/3587, ICRF-EXT.2)
B = VLBA (Beasley et al., Cat. J/ApJS/141/13, VCS1,
Fomalont et al., Cat. J/AJ/126/2562, VCS2)
C = VLA-015, VLA catalog minus 15 sources, (Cat. J/ApJS/141/13,
J/AJ/126/2562, J/AJ/129/1163, J/AJ/131/1872)
Note (2): Position and photometric magnitudes are from the Large Quasar
Astrometric Catalogue (LQAC), Cat. J/A+A/494/799
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Acknowledgements:
Dan Alin Nedelcu, nedelcu (at)aira.astro.ro
(End) Dan Alin Nedelcu [A.I.R.A.], Patricia Vannier [CDS] 10-Dec-2009