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I/250 The Tycho Reference Catalogue (Hog+ 1998)
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The Tycho Reference Catalogue
Hog E., Kuzmin A., Bastian U., Fabricius C., Kuimov K.,
Lindegren L., Makarov V.V., Roeser S.
<Astron. Astrophys. 335L, 65 (1998)>
=1998A&A...335L..65H
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ADC_Keywords: Positional data; Proper motions ; Astrographic zones;
Historical catalog; Photographic catalog; Surveys;
Cross identifications
Keywords: astrometry - reference catalogs - proper motions -
Astrographic Catalogue - Tycho Catalogue
Mission_Name: Hipparcos
Abstract:
The Tycho Reference Catalogue (TRC) contains high-quality positions
and proper motions for 990182 stars of the Tycho Catalogue. The proper
motions were derived from Tycho positions and Astrographic Catalogue
positions reduced to the Hipparcos system. The median accuracy of the
TRC position components is 40 mas at J1991.25. The median accuracy of
the proper motion is about 2.5 mas/yr. Systematic errors are less than
about 1.0 mas(/yr). The quality of the proper motions in TRC is
assessed by comparison with the Hipparcos and Tycho Catalogues.
Comparison with the recent ACT Catalogue which is based on an
independent reduction of the same observations as used for
constructing the TRC is reported.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
trc_1.dat 148 31246 TRC catalogue [0,15[
trc_2.dat 148 30974 TRC catalogue [15,30[
trc_3.dat 148 30529 TRC catalogue [30,45[
trc_4.dat 148 27913 TRC catalogue [45,60[
trc_5.dat 148 31595 TRC catalogue [60,75[
trc_6.dat 148 44777 TRC catalogue [75,90[
trc_7.dat 148 54988 TRC catalogue [90,105[
trc_8.dat 148 63683 TRC catalogue [105,120[
trc_9.dat 148 55196 TRC catalogue [120,135[
trc_10.dat 148 42097 TRC catalogue [135,150[
trc_11.dat 148 38140 TRC catalogue [150,165[
trc_12.dat 148 34090 TRC catalogue [163,180[
trc_13.dat 148 31197 TRC catalogue [180,195[
trc_14.dat 148 32700 TRC catalogue [195,210[
trc_15.dat 148 33615 TRC catalogue [210,225[
trc_16.dat 148 37309 TRC catalogue [225,240[
trc_17.dat 148 40803 TRC catalogue [240,255[
trc_18.dat 148 46278 TRC catalogue [255,270[
trc_19.dat 148 53453 TRC catalogue [270,285[
trc_20.dat 148 58342 TRC catalogue [285,300[
trc_21.dat 148 58001 TRC catalogue [300,315[
trc_22.dat 148 43332 TRC catalogue [315,330[
trc_23.dat 148 37455 TRC catalogue [330,345[
trc_24.dat 148 32469 TRC catalogue [345,360[
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See also:
I/220 : The HST Guide Star Catalog (Lasker+ 1992)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/246 : The ACT Reference Catalog (Urban+ 1997)
Byte-by-byte Description of file: trc_1.dat, trc_2.dat, trc_3.dat, trc_4.dat,
Byte-by-byte Description of file: trc_5.dat, trc_6.dat, trc_7.dat, trc_8.dat
Byte-by-byte Description of file: trc_9.dat, trc_10.dat, trc_11.dat, trc_12.dat
Byte-by-byte Description of file: trc_13.dat, trc_14.dat, trc_15.dat, trc_16.dat
Byte-by-byte Description of file: trc_17.dat, trc_18.dat, trc_19.dat, trc_20.dat
Byte-by-byte Description of file: trc_21.dat, trc_22.dat, trc_23.dat, trc_24.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TYCID1 [1,9537] TYCID1 from TYC (1)
6- 10 I5 --- TYCID2 [1,12119] TYCID2 from TYC (1)
12 I1 --- TYCID3 [1,2] TYCID3 from TYC (1)
14- 25 F12.8 deg RAdeg Right Ascension, ICRS, at epoch J2000
27- 38 F12.8 deg DEdeg Declination, ICRS, at epoch J2000
40- 45 F6.1 mas/a pmRA [-212.7,210.1] prop. mot. in RA * cos(dec)
47- 52 F6.1 mas/a pmDE [-216.6,210.6] proper motion in Dec
54- 60 F7.2 a epRA [1923.68,1991.25] mean epoch of RA (2)
62- 68 F7.2 a epDE [1934.88,1991.25] mean epoch of Dec (2)
70- 74 F5.1 mas e_RAdeg s.e. RA * cos(dec), at mean epoch (3)
76- 80 F5.1 mas e_DEdeg s.e. of Dec at mean epoch (3)
82- 85 F4.1 mas/a e_pmRA [1.6,24.0] s.e. prop mot in RA * cos(dec)
87- 90 F4.1 mas/a e_pmDE [1.6,24.1] s.e. of proper motion in Dec
92- 97 F6.3 mag BT [0.312,13.086]? Tycho BT magnitude (4)
99-103 F5.3 mag e_BT [0.001,0.3]? s.e. of BT (4)
105-110 F6.3 mag VT [0.283,15]? Tycho VT magnitude (4)
112-116 F5.3 mag e_VT [0.001,0.3]? s.e. of VT (4)
118-119 I2 --- Num [2,13] Number of positions used (5)
121 I1 --- q_pm [0,9] quality flag for proper motion (6)
123-128 I6 --- HD [1,359021]? HD identifier from TYC
130-135 I6 --- HIP [1,120404]? Hipparcos number from TYC
136-137 A2 --- CCDM CCDM component identifier from TYC (7)
139-144 F6.2 mas Plx [0.52,202.69]? parallax for HIP stars (8)
146 A1 --- dupflg [ DS] duplicity flag (9)
147 A1 --- varflg [ V] variability flag (10)
148 A1 --- ACTflg [ TX] ACT flag (11)
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Note (1): The TYCID1 is the GSC region number, the TYCID2 is the
running number within the region, the TYCID3 is a component
identifier (normally 1). Some non-GSC running numbers were
constructed for TYC. The recommended star designation contains
a hyphen between the TYCID numbers, e.g. TYC 1-13-1.
Note (2):
The mean epochs are given in Julian years.
Note (3):
The standard errors given are for the mean epoch. They are in
the range 1.0-117.1.
The standard errors at some epoch, t, are obtained as
e_RA(t)* = sqrt((f*e_RA*)^2^ + ((e_pmRA*)*(t-epRA))^2^ ) and
e_DE(t) = sqrt((f*e_DE)^2^ + (e_pmDE*(t-epRA))^2^ )
A factor f=1.5 would give realistic standard errors for the
majority of stars. This factor compensates for too small
formal errors of positions in the Tycho Catalogue (Cf.
Sect 18.4 of Vol 4 of "The Hipparcos and Tycho Catalogues",
ESA SP-1200, 1997).
Note (4):
The BT and VT photometry is copied from the Tycho Catalogue.
Approximate Johnson photometry may be obtained as:
V = VT -0.090*(BT-VT)
B-V = 0.850*(BT-VT)
Consult Sect 1.3 of Vol 1 of "The Hipparcos and Tycho Catalogues",
ESA SP-1200, 1997, for details.
Note (5):
Between 2 and 13 positions (TYC plus 1-12 AC positions) were
used in the adjustment:
Npos: 2 3 4 5 6 7 8 9 10 11 12 13
Stars: 20183 588096 312449 47150 18045 3169 742 217 81 33 14 3
Note (6):
q_pm (0..9) gives twice the ratio of the estimated s.e. to the
formal s.e. A large value may be taken as a warning. The value 9
marks proper motions deviating from HIP values by more than six
combined standard errors. Separate values were computed for R.A.
and Dec. Here the maximum value is given. The quality flag was
computed prior to the adjustment of the standard errors (Cf Sect 3
of Hoeg et al. 1998).
q_pm: 0 1 2 3 4 5 6 7 8 9
Stars 35082 271197 319970 183564 93971 45973 22662 11459 3494 2810
Note (7):
The CCDM component identifier is only given for HIP stars. It is
copied from field T51 of the Tycho Catalogue.
Note (8):
The parallax for HIP stars is copied from field H11 of the
Hipparcos Catalogue, but only when it exceeds the standard error.
The HIP parallax was NOT used in the construction of the TRC.
Note (9):
the duplicity flag is set for 16587 stars where duplicity was
clearly indicated or suspected in the Tycho data, but not
resolved. (T49 is D or S in TYC).
Note (10):
the variability flag is set for 18505 stars with known
variability. (T47 set or T48='V' in TYC).
Note (11):
' ' = also in ACT, proper motion agrees within 10 mas/yr in both
coordinates;
'T' = only in TRC (39892 stars);
'X' = also in ACT, does not agree within 10 mas/yr (19104 stars).
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History:
18-Apr-2002, by Gail L. Schneider [ADC]: The original catalog was split in 24
files according to degrees of Right Ascension to avoid large files. Removed
index.dat file.
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(End) Claus Fabricius [Niels Bohr Institute for Astronomy] 03-Apr-1998