J/A+A/375/308 Extension of ICRF for selected areas down to V=15 (Camargo+ 2001)
Extension of the ICRF for selected areas down to the 15th V magnitude
Camargo J.I.B., Teixeira R., Benevides-Soares P., Ducourant C.
<Astron. Astrophys., 375, 308-318 (2001)>
=2001A&A...375..308C 2001A&A...375..308C
ADC_Keywords: Positional data ; Proper motions
Keywords: astrometry
Description:
A catalogue of accurate positions and proper motions for 41,721
objects is provided. Objects are within areas of special astronomical
interest, containing extragalactic radio sources, mostly from ICRF
(see Cat. I/251), and pre-main-sequence (PMS) stars in Southern
star-forming regions (Chamaeleon, Lupus and Upper Scorpius-Ophiuchus).
Positions and proper motions were derived by combining current epoch
positions, obtained with the Valinhos CCD meridian circle (VMC, see
1999A&AS..134..173V 1999A&AS..134..173V), with first epoch catalogues, AC2000 (I/247) and
USNO-A2.0 (I/252) mainly, as well as positions from plate measurements
performed with the MAMA measuring machine (Guibert J., Charvin P. &
Stoclet P., 1983, in Proceedings of the 78th Colloquium of the IAU),
in Paris. On average, objects with V≤14.0 have positional precisions
better than 50mas in both coordinates, and 100mas near the detection
limit of the VMC (V∼16,0). For proper motions, average precisions are
better than 4mas/year, whatever the magnitude, when delta≥-17°.
To the south of this declination, a magnitude dependence is verified
due to a particular feature of the USNO-A2.0's epochs, providing
figures of 3mas/year when V≤12.0, where the participation of AC2000
is noted, and reaching 17mas/year at the detection limit.
The catalogue data is grouped by area, following the same order and
identification as given in table 2 of the paper; within each area,
objects are sorted by right ascension. The respective record numbers
for the beginning of each area are provided in a separate table.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
vmcc.dat 138 41721 Valinhos meridian circle catalogue
regions.dat 28 51 Region identifications (Table 2 of the paper)
with record numbers in vmcc.dat
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/247 : The AC2000 Catalogue (Urban+ 1997)
I/251 : VLBI International Celestial Reference Frame (ICRF) (Ma+, 1997)
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
Byte-by-byte Description of file: vmcc.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right Ascension J2000 (hours), at epoch EpRA
4- 5 I2 min RAm Right Ascension J2000 (minutes)
7- 12 F6.3 s RAs Right Ascension J2000 (seconds)
14 A1 --- DE- Declination J2000 (sign)
15- 16 I2 deg DEd Declination J2000 (degrees), at epoch EpDE
18- 19 I2 arcmin DEm Declination J2000 (minutes)
21- 25 F5.2 arcsec DEs Declination J2000 (seconds)
27- 30 I4 mas/yr pmRA Proper motion in R.A.*cos(dec) (J2000)
32- 35 I4 mas/yr pmDE Proper motion in D.E. (J2000)
37- 40 F4.1 mag Vmag V magnitude as obtained from the VMC
42- 49 F8.3 yr EpRA R.A. epoch
51- 58 F8.3 yr EpDE D.E. epoch
60- 62 I3 mas e_RAs Positional error in R.A.*cos(dec) for EpRA
64- 66 I3 mas e_DEs Positional error in D.E. for EpDE
68- 69 I2 mas/yr e_pmRA Proper motion error in R.A.*cos(dec)
71- 72 I2 mas/yr e_pmDE Proper motion error in D.E.
74- 80 I7 --- HIP ?HIPPARCOS (I/239) Catalogue number
82- 93 A12 --- TYC ?Tycho-2 number (see Note (1) in I/259)
94 A1 --- f_TYC [ *] presence in Tycho-1 catalogue (1)
97-105 I9 --- AC2000 ? AC2000 (I/247) number
108-114 I7 --- ACRS ? ACRS (I/171) number
116-124 A9 --- DM ? Durchmusterung (BD/CD/CPD) number
126-131 I6 --- SAO ? SAO (I/131) number
133-138 I6 --- HD ? HD (III/135) number
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Note (1):
'*' = Object not present in Tycho-1 catalogue (I/239).
' ' = Object present in Tycho-1 catalogue.
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Byte-by-byte Description of file: regions.dat
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Bytes Format Units Label Explanations
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2- 6 I5 --- RecNo Record number of first record in vmcc.dat file
8- 28 A21 --- Region Region name as in Table 2 of the paper
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Acknowledgements:
Julio Ignacio Bueno de Camargo
(End) J.I.B. de Camargo [Univ. Sao Paulo] 25-Jul-2001