I/174 Yale Trigonometric Parallaxes Preliminary (van Altena+ 1991)
The General Catalogue of Trigonometric Stellar Parallaxes, Preliminary Version
van Altena W.F., Lee J.T., Hoffleit D.
<Yale University Observatory (1991)>
ADC_Keywords: Parallaxes, trigonometric
Description:
The preliminary edition of the General Catalogue of Trigonometric
Stellar Parallaxes, containing 15349 parallaxes for 7879 stars, has
been prepared at the Yale University Observatory. In this edition 1480
stars have been added to those contained in the previous edition of
the catalog by Jenkins (1952, 1963). This relatively small increase in
the number of stars is more than compensated for by the increased
accuracy of the newer trigonometric parallaxes.
The authors have attempted to include here all trigonometric
parallaxes made available to them by March 1991 and will provide for
each listed parallax in the final version the reference to its source
of publication.
For each star it lists the equatorial coordinates for B1900 and the
secular variation for 100 years, the proper motion in x and y, the
weighted average absolute parallax and its standard error, the number
of parallax observations, the quality of interagreement among the
different values, the visual magnitude, and various cross
identifications with other catalogs. The B1900 equinox has been
maintained to avoid assigning yet another star number. Ancillary
information, including UBV photometry, MK spectral types, data on the
variability and binary nature of the stars, orbits when available, and
miscellaneous information to aid in determining the reliability of the
data, will be listed in the final version.
The relative parallaxes are corrected to absolute parallax using newly
computed corrections that are based on an improved model of the
galaxy. An analysis of the resulting absolute parallaxes has been made
to study the accidental and systematic errors of the parallaxes. The
results of that investigation are used to arrive at a weighting system
for the catalog, which then yields weighted absolute parallaxes for
each star. The weighting system is still under investigation;
therefore, the weighted parallaxes may change a bit in the final
version.
Printed copies of the catalog will be available from the Yale
University Observatory when the work has been completed (late 1993?).
See the file cdrom.doc which provides the original documentation by
W. van Altena.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cdrom.doc 80 128 The CD-ROM Original Documentation
catalog 191 8573 The Preliminary Catalogue
(see also Note 1 below)
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Byte-per-byte Description of file: catalog
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Bytes Format Units Label Explanations
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2- 8 A7 --- GCTP Catalog number, blank if not yet assigned
10 A1 --- Comp [A-FM] Component identification or
'M' for unresolved
11 A1 --- VFlag [V] Variable flag
12 A1 --- n_Comp [OS] Double star information code:
'O' for orbital data available;
'S' for separation and position data
available.
14- 25 A12 --- Name Star name (see file cdrom.doc)
27- 28 I2 h RAh ? Hours RA, B1900.0 (SEE NOTE 1)
30- 31 I2 min RAm ? Minutes RA, B1900.0
33- 38 F6.3 s RAs ? Seconds RA, B1900.0
40 A1 --- DE- ? Sign Dec, B1900.0
41- 42 I2 deg DEd ? Degrees Dec, B1900.0
44- 45 I2 arcmin DEm ? Minutes Dec, B1900.0
47- 51 F5.2 arcsec DEs ? Seconds Dec, B1900.0
52 A1 --- Source Code for source of coordinates:
'A' indicates the Catalog of Astrometric
Data; (SEE NOTE 1)
'P' indicates other sources. (1)
53- 57 I5 0.01min/yr Var_RAm ? Secular variation in RAm
58- 64 F7.3 0.01s/yr Var_RAs ? Secular variation in RAs
65- 68 I4 0.01arcmin/yr Var_DEm ? Secular variation in DEm
69- 74 F6.2 0.01arcsec/yr Var_DEs ? Secular variation in DEs
76- 83 F8.4 arcsec/yr pmRA ? Proper motion in RA
84- 91 F8.4 arcsec/yr pmDE ? Proper motion in Dec
96-102 F7.4 arcsec Par ? Weighted average absolute trig. parallax
104-106 I3 0.1mas e_Par ? Parallax standard error
109-110 I2 --- o_Par ? Number of observations used in Parallax
112 A1 --- q_Par [GFP] Parallax quality:
'G' good;
'F' fair;
'P' poor
114-118 F5.2 mag Mag ? Magnitude:
V magnitude for values with two digits
after decimal;
visual magnitude for values with a
single digit after decimal
see also n_mag
119 A1 --- n_Mag [HJPRVv:*]
'P' for blue passband magnitude for mag
'H' for Harvard magnitude
'J' for Joint photometry
'v' for visual magnitude
'V' for V-I color
'R' for R-I color
120 A1 --- HRSupp [S] 'S' if in supplement to
Bright Star Catalog
121-124 I4 --- HR [1/9110]? Harvard Revised (HR)
126-131 I6 --- HD [1/359083]? Henry Draper
132-142 A11 --- DM Durchmusterung identification:
catalog 'BD', 'CD', 'CP' in bytes 132-133;
catalog number, SZZNNNNN in bytes 134-141
component identification in byte 142
145-150 A6 --- Gliese Gliese number (2)
153-167 A15 --- VarName Variable star name;
'S' indicates NSV number
173-177 A5 --- ADS Double Star Designation (3)
179-192 A14 --- Other Other star name
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Note (1): Precession error in the 1900 R.A.s coded "A":
To: Users of the General Catalogue of Trigonometric Parallaxes,
Preliminary Version of 1991 on the Astron. Data Center CDROM.
From: W. van Altena, Yale Astronomy Dept., P.O. Box 6666, New Haven, CT
(203)-432-3020 -
Re: Precession error in the 1900 R.A.s coded "A".
An unfortunate coding error slipped by us in the final formatting
program for the preliminary version of the Yale Parallax Catalogue, 1991
(YPCP) when allowing for the variety of units possible for the proper
motion. The error affects only those right ascensions from the ARICAT
coded "A". In those cases, the original epoch and equinox was B1950.0 and
the "cos delta" term in the proper motion in right ascension was
inadvertently omitted by us from the precession from B1950.0 to B1900.0.
This error can amount to several seconds of time during the 50-year
interval.
Fortunately, an easy fix is available that will usually provide right
ascensions accurate to a few hundredths of a second of time at 1900.0 since
only the proper motion was omitted. The algorithm suggested to correct
the "A" right ascensions is:
R.A. (Correct) = R.A.(YPCP 1900) - (50/15)*PM(RA "/yr)*[1/cos(Dec) - 1.0].
In a similar way, the secular variation (SV) in right ascension for 100
years can be corrected for these same "A" stars by using the following
algorithm.
SV (Correct) = SV (YPCP) + (100/15)*PM(RA "/yr)*[1/cos(Dec) - 1.0].
The error in the 1900 right ascensions corrected by the above algorithm
is normally less than a few hundredths of a second of time. However, for
those cases where the declination is greater than 80 degrees, the error can
exceed one second of time.
I regret the occurrence of this error and any inconvenience that it
may have caused. In addition, I am grateful to Dr. F. Crifo and Dr. H.
Jahreiss for drawing my attention to it as soon as they discovered the
error.
Sincerely,
William F. van Altena.
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Note (2):
Number in Catalogue of Nearby Stars (Gliese, et al. 1984);
number with decimal point is number in 1969 catalog (Gliese 1969);
number beginning with 1 thousand is Gliese-Jahreiss No.
(Gliese & Jahreiss 1984);
number beginning with 9 thousand is Woolley No. (Woolley et al. 1970);
'N' is new star not yet numbered.
Note (3): Aitken's Double Star Catalog (ADS) designation;
other codes also used:
'W' if listed in Washington Visual Double Star Catalog (Wooley 1984);
'A' if astrometric binary;
'B' spectroscopic binary;
'E' eclipsing binary;
'O' occultationary binary;
'S' if speckle interferometric binary.
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See also:
I/81 : General Catalogue of Trigonometric stellar parallaxes and
Supplement, Jenkins L.F., 1952, 1963
I/60 : Data on Trigonometric parallaxes which have been used in
the Yale Catalogue (right-hand pages of the Catalogue and its
Supplement)
V/70 : Nearby Stars, Preliminary 3rd Version (Gliese W. and
Jahreiss H, 1991)
Historical Notes:
* Modifications made at CDS (Francois Ochsenbein, 25-Oct-1993)
5304.00 (BD+85 368) magnitude changed from 0.3 to 10.3
AC+43 447-29 pmRA was misaligned
* Documentation file revisited on 25-Oct-1995
* The unit of parallax error e_Par (bytes 104-106) was corrected from
arcsec to 10-4arcsec = 0.1mas on 07-Nov-1996
(End) [CDS] 25-Oct-1995