I/138 Southern Reference Star Catalogue (Smith+ 1988)
The Southern Reference Star Catalogue of 20488 Positions referred without
proper motions to the FK4 system and the equinox and equator of B1950.0
at the mean epoch of observation.
Smith Jr. C.A., Jackson E.S., Corbin T.E., Hughes J.A., Khrutskaya E.V.,
Polojentsev A.D., Polojentsev D.D., Yagudin L.I., Zverev M.S.
<in IAU Symposium 141, Inertial Coordinate System on the Sky,
ed. J.H. Lieske and V.K. Abalakin, 457 (1988)>
ADC_Keywords: Positional data ; Proper motions
Description:
The positions are the combined results of observations of all
participants in the Southern Reference Star (SRS) observing campaign
from 1961 tO 1973. Preliminary catalogs were compiled at both the U.S.
Naval Observatory (Washington) and the Pulkovo Observatory
(Leningrad). The two compilations were compared, reconciled and
combined to give the catalog described here.
The proper motions have been culled from a number of different sources
and should not be regarded as part of the SRS observed catalog. The
proper motions are given principally as a means to take into account
the small differences in epoch of observation between the SRS and the
2nd Cape Photographic Catalog plate material, which is at most about
two years.
Because of the inhomogeneous nature of the proper-motion sources and
the likely presence of magnitude related systematic errors in the
proper motions, they may not safely be used to extend the SRS system
of positions very far from the mean epoch of observation which is
about 1968. A discussion by T. Corbin of all the SRS observations
including those made before and after the 1961 to 1973 campaign and
their reduction to the FK4 system is at an advanced stage of
preparation and will yield the desired high quality proper motions
required for transferring the system to more distant epochs.
Two sets of positions and proper motions are given. One set is
referred to the equator and equinox of B1950.0 and the other to the
equator and equinox of J2000.0. The positions are referred to the mean
epoch of observation in both cases.
The B1950.0 positions were linked directly to the system of FK4 by
observational techniques.
The J2000.0 data are based on a transformation of the B1950.0 data.
The transformation was accomplished in two steps. First, FK5-FK4
differences referred to the B1950.0/FK4 system were added to the SRS
positions and proper motions. The FK5-FK4 differences are those given
by the analytical coefficients of H. Schwan (Astronomisches
Rechen-Institut, Heidelberg). Second, the reduction from B1950.0 to
J2000.0 was accomplished by using the conversion procedure described
in the 1988 edition of THE ASTRONOMICAL ALMANAC (pg. B42).
The (FK5-FK4) differences are given along with the average FK4
magnitude used as the input argument to Schwan's subroutines. An
average FK4 magnitude was estimated for each SRS position from the
average magnitude of all FK4 stars in an area on the celestial sphere
bounded by a four-hour interval in right ascension and a 20-degree
interval in declination centered on the SRS. All SRS less than 10 deg
from the pole were treated as if they had been at -80 deg declination
for the calculation of the average FK4 magnitude only.
This transformation procedure gives a first order reduction from the
FK4 to the FK5 system. A more precise reduction of many of the SRS
catalogs observed from 1961 to 1973 is possible from a re-discussion
of the FK4 star observations made concurrently with the SRS
observations on a nightly basis. A program to reduce first the SRS and
then the AGK3R to the FK5 system as directly as possible, going back
to the nightly observations of FK4/FK5 when they are available, is now
in progress at the observatory in Washington.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
intro.txt 80 297 Original description
main.dat 167 20488 The Southern Reference Star Catalogue
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Byte-by-byte Description of file: main.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Serial Number of the record
in order of B1950.0 right ascension.
6 A1 --- f_pm Proper motion code:
* = Preliminary proper motion (T. Corbin).
C = Cape, Yale, GC, etc.
7- 11 I5 --- SRS Original SRS number in the observing list.
12- 19 A8 --- DM Durchmusterung number
20- 21 I2 dmag m Magnitude in 0.1mag
22- 23 A2 --- Sp Spectral type
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Position at Equator and Equinox of B1950.0, at the mean epoch of observation
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24- 25 I2 h RAh Right Ascension B1950, at mean epoch (hour)
26- 27 I2 min RAm Right Ascension B1950, at mean epoch (minute)
28- 32 I5 ms RAms Right Ascension B1950, at mean epoch (0.001s)
33- 38 I6 ms e_RAms Mean error of the right ascension.
Referred to the equator by multiplication
with cosine of the declination.
39- 40 I2 --- NaW Number of observations in right ascension
(Washington compilation).
41- 45 I5 myr EpRA-1900 Mean epoch of observation of the right ascension
minus B1900.0 (in 0.001 tropical years)
46 A1 --- DE- Declination B1950, at mean epoch (sign)
47- 48 I2 deg DEd Declination B1950, at mean epoch (degrees)
49- 50 I2 arcmin DEm Declination B1950, at mean epoch (arcmin)
51- 54 I4 10mas DEcs Declination B1950, at mean epoch (0.01arcsec)
55- 58 I4 10mas e_DEcs *Mean error of the declination, in 0.01arcsec
59- 60 I2 --- NdW Number of observations in declination
(Washington compilation).
61- 65 I5 myr EpDE-1900 Mean epoch of observation of the declination
minus B1900.0 (in 0.001 tropical years)
66 I1 --- CaW Number of catalogs in right ascension
(Washington compilation).
67 I1 --- CdW Number of catalogs in declination
(Washington compilation).
69- 70 I2 --- NaP Number of observations in right ascension
(Pulkovo compilation).
71- 72 I2 --- NdP Number of observations in declination
(Pulkovo compilation).
73 I1 --- CaP Number of catalogs in right ascension
(Pulkovo compilation).
74 I1 --- CdP Number of catalogs in declination
(Pulkovo compilation).
81- 86 I6 10us/yr pmRA Approximate proper motion in right ascension
(B1950.0), in milli-seconds (time)
per tropical century.
87- 92 I6 0.1mas/yr pmDE Approximate proper motion in declination
(B1950.0), in 0.01 arcseconds (")
per tropical century.
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Differences (FK5-FK4) giving the reduction to the FK5 system in the FK4 system
from the coefficients of the analytical representation by H. Schwan (ARI).
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97-101 F5.3 s dRA Difference (FK5-FK4) in Right Ascension
104-107 F4.2 arcsec dDE Difference (FK5-FK4) in Declination
109-114 F6.3 10ms/yr dpmRA *Difference (FK5-FK4) in Proper motion in
right ascension, expressed in seconds (time)
per tropical century
117-120 F4.2 10mas/yr dpmDE Difference (FK5-FK4) in Proper motion in
declination, expressed in seconds (")
per tropical century
122-125 F4.2 mag mag Adopted average FK4 magnitude for this star.
(Input to Schwan's analytical functions.)
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Position at Equator and Equinox of J2000.0, at the mean epoch of observation
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126-127 I2 h RAJh *Right Ascension J2000 (hours)
128-129 I2 min RAJm *Right Ascension J2000 (minutes)
130-134 I5 ms RAJms *Right Ascension J2000 (0.001s)
135-140 I6 10us/yr pmRAJ Approximate proper motion in right ascension
(J2000.0; is ms/century)
141-146 I6 myr EpRA-2000 Mean epoch of observation of the right ascension
minus J2000.0, expressed in 0.001 Julian years.
147 A1 --- DEJ- *Declination J2000 (sign)
148-149 I2 deg DEJd *Declination J2000 (degrees)
150-151 I2 arcmin DEJm *Declination J2000 (arc minutes)
152-155 I4 10mas DEJcs *Declination J2000 (0.01arcsec)
156-161 I6 0.1mas/yr pmDEJ Approximate proper motion in declination
(J2000.0; is ms/century)
162-167 I6 myr EpDE-2000 Mean epoch of observation of the declination
minus J2000.0, expressed in 0.001 Julian years.
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Note on dpmRA, e_DEs: (remark added at CDS)
- cols 55-58 are *-filled in records #2241 and #19064.
- col 109 was stated as blank in the original description;
it is not blank for record #936
Note on RAJh, RAJm, RAJms, DEJ-, DEJd, DEJm, DEJcs:
The positions transformed approximately to the FK5 system and referred
to the equator and equinox of J2000.0 are given for interim use.
Note on e_DEcs: columns were *-filled in records ##2241 and #19064;
these values were replaced by 9's in June 2004.
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History:
* 08-Dec-1992: First version of the description
* 08-May-2004: ReadMe Standardisation (Francois Ochsenbein, CDS)
(End) Francois Ochsenbein [CDS] 08-Dec-1992