J/AJ/114/850 Errors in the FK5 Catalog (Stone 1997)
Systematic errors in the FK5 catalog as determined from CCD observations in the
extragalactic reference frame
Stone R.C.
<Astron. J. 114, 850 (1997)>
=1997AJ....114..850S 1997AJ....114..850S
ADC_Keywords: Fundamental catalog ; Positional data
Abstract:
This paper presents new positions for 689 FK5 stars determined
directly in the extragalactic reference system from CCD scan
observations made with the Flagstaff Astrometric Scanning Transit
Telescope (FASTT). All the observations were made in 1994-1996 with an
accuracy of ~±40mas in each coordinate. When these positions are
compared with their counterparts in the FK5 catalog, systematic errors
in the FK5 are found that vary in both right ascension and declination
and can be as large as 100 mas in magnitude. No magnitude-dependent
errors in the FK5 were found. Moreover, the true error in FK5 star
positions is determined to be ~±80mas in both coordinates or two
times the expected catalog positional errors. There is an excellent
agreement between the systematic errors in the FK5 found in this paper
and those presented in Lindegren et al. (1995A&A...304...44L 1995A&A...304...44L)
comparing FK5 and Hipparcos 30-month star positions. By comparing
corresponding FASTT and FK5 star positions, the link between the
optical and extragalactic reference frames was determined and is given
by the following rotations
(ωx,ωy,ωz) = (3±5, 25±5, 16±4) (s.e.)
mas, which agree well with previous determinations made by other
investigators. Two of the rotations (ωy,ωz) are
significantly larger than their standard errors and, therefore,
presumably real. Finally, since these rotations are small (≤25mas),
the FK5 and extragalactic reference frames must be closely aligned to
one another.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table.dat 102 689 FK5 star positions determined in the
extragalactic reference frame with
the FASTT CCD meridian telescope
--------------------------------------------------------------------------------
See also:
I/149A : Fifth Fundamental Catalogue (FK5) Part I (Fricke+, 1988)
I/175 : Fifth Fundamental Catalogue (FK5) - Extension (Fricke+ 1991)
Byte-by-byte Description of file: table.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq Running number
5- 9 I5 --- FK5 FK5 star number (Cat. I/149, I/175)
12- 17 I6 --- HD HD designation
19- 22 F4.1 mag Vmag V magnitude taken from FK5 catalog
25- 26 I2 h RAh Right ascension, J2000
28- 29 I2 min RAm Right ascension, J2000
31- 37 F7.4 s RAs Right ascension, J2000
39- 42 F4.1 10-4s e_RAs Standard error in RA
44- 46 I3 --- o_RAh Number of times observed in RA
49- 54 F6.3 yr EpRA-1900 Mean epoch of RA coordinate (+ 1900)
56- 62 F7.3 10-2s/yr pmRA Proper motion in RA taken from FK5
65 A1 --- DE- Declination sign
66- 67 I2 deg DEd Declination, J2000
69- 70 I2 arcmin DEm Declination, J2000
72- 77 F6.3 arcsec DEs Declination, J2000
79- 81 I3 mas e_DEs Standard error in DE
83- 85 I3 --- o_DEd Number of times observed in DE
88- 93 F6.3 yr EpDE-1900 Mean epoch of DE coordinate (+ 1900)
96-102 F7.2 10mas/yr pmDE Proper motion in DE taken from FK5
--------------------------------------------------------------------------------
Origin: AAS CD-ROM series, Volume 9, 1997 Lee Brotzman [ADS] 27-Sep-1997
(End) [CDS] 05-Feb-1998