J/A+A/383/1062 Optical positions of 55 radio stars at Yunnan Obs. (Hu+, 2002)
Optical positions of 55 radio stars from astrolabe observations of
Yunnan Observatory
Hu H., Wang R.
<Astron. Astrophys. 383, 1062 (2002)>
=2002A&A...383.1062H 2002A&A...383.1062H
ADC_Keywords: Stars, radio
Keywords: astrometry - radio continuum: stars
Abstract:
The observations by the photoelectric astrolabe at Yunnan Observatory
relative to the Hipparcos Catalogue (Cat. I/239) and the optical
positions of 55 radio stars were obtained from observations between
1991 and 2000. They all resulted from processing the photon counts
obtained by means of the astrolabe after the automation of the
instrument. There are 46 stars in common with the Hipparcos Catalogue.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 81 55 55 radio star positions (Mean epoch of
observations; equator and equinox J2000)
table2.dat 56 55 The external accuracy of the 55 radio star
positions
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See also:
V/67 : An astrometric catalogue of radio stars (Walter+, 1990)
II/199 : Radio continuum emission form stars (Wendker, 1995)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/A+AS/118/239 : Yunnan Observatory photoelectric astrolabe catalog (Hu+ 1996)
J/A+AS/136/531 : Valinhos CCD Meridian Circle radio stars (Lopes+, 1999)
J/A+AS/122/529 : Radio stars for linking celestial reference frames
(Walter+, 1997)
J/A+AS/89/311 : Optical positions of 221 radio stars (Requieme+, 1991)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Name of star
16- 19 I4 --- Num ? Number in the astrometric catalogue of
radio stars (Cat. V/67)
21- 26 I6 --- HIP ? Number in the Hipparcos Catalogue I/239
28- 32 F5.2 mag mvis Observed mean visual magnitude
34- 35 I2 h RAh Right ascension for equator and equinox
J2000.0 and epoch Ep-1900
37- 38 I2 min RAm Right ascension for equator and equinox
J2000.0 and epoch Ep-1900
40- 45 F6.3 s RAs Right ascension for equator and equinox
J2000.0 and epoch Ep-1900
47- 51 F5.3 s e_RAs Mean errors of right ascension
53 A1 --- DE- Declination sign (J2000.0)
54- 55 I2 deg DEd ? Declination for equator and equinox
J2000.0 and epoch Ep-1900 (1)
57- 58 I2 arcmin DEm ? Declination for equator and equinox
J2000.0 and epoch Ep-1900 (1)
60- 64 F5.2 arcsec DEs ? Declination for equator and equinox
J2000.0 and epoch Ep-1900 (1)
66- 69 F4.2 arcsec e_DEs ? Mean errors of declination
71- 72 I2 --- NtransE Number of the observed transits in east
74- 75 I2 --- NtransW Number of the observed transits in west
77- 81 F5.2 yr Ep-1900 Mean epoch of observations minus 1900.00
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Note (1): 21 stars have no declination, as it is indicated in the
section 2 of the paper, i.e. "Since for cosq<0.3 (i.e. abs(cosq)<0.3)
the declinations are obtained by the astrolabe with a rather low
precision, they are not given in the catalogue".
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Name of star
16- 19 I4 --- Num ? Number in the astrometric catalogue of
radio stars (V/67)
21- 26 I6 --- HIP ? Number in the Hipparcos Catalogue (I/239)
28- 32 F5.2 mag mvis Observed mean visual magnitude.
34- 36 I3 0.01arcsec DRAH-Y ? Differences HIC-YPA in right ascension (1)
38- 40 I3 0.01arcsec DDEH-Y ? Differences HIC-YPA in declination (1)
42- 44 I3 0.01arcsec DRAB-Y ? Differences BORD-YPA in right ascension (1)
46- 48 I3 0.01arcsec DDEB-Y ? Differences BORD-YPA in declination (1)
50- 52 I3 0.01arcsec DRAU-Y ? Differences USNO-YPA in right ascension (1)
54- 56 I3 0.01arcsec DDEU-Y ? Differences USNO-YPA in declination (1)
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Note (1): Position differences:
HIC: Hipparcos Input Catalogue, Version 2 (Turon et al., 1993, Cat. I/196)
BORD: Optical positions of 221 radio stars (Requieme et al., 1991
Cat. J/A+AS/89/311)
USNO: The USNO-A2.0 Catalogue (Monet et al., 1998, Cat. I/252)
YPA: this work
Mean values in mas (0.001"):
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HIC-YPA BORD-YPA USNO-YPA
RA DE RA DE RA DE
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Mean difference -4 8 11 -40 -12 -9
Standard deviation
of the mean difference 14 19 15 25 17 29
Standard deviation
of the difference 95 103 101 128 99 127
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Acknowledgements: Hui Hu
(End) Patricia Bauer [CDS] 25-Jan-2002