The following document lists the file desc.txt
from catalogue I/193.
A plain copy of the file
(without headers/trailers) may be downloaded.
1
I/193 Page 1
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* PPM South Star Catalogue *
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- compiled by
0 U. Bastian (1) and S. Roeser (1)
- in collaboration with
0 L.I. Yagudin (2) and V.V. Nesterov (3)
- with contributions from
0 D.D. Polozhentsev (2), Kh.I. Potter (2),
R. Wielen (1) and Ya.S. Yatskiv (4)
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0 1) Astronomisches Rechen-Institut, Heidelberg,
2) Pulkovo Observatory, St. Petersburg,
3) Sternberg Institute, Moscow,
4) Kiev Observatory, Kiev.
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0 Heidelberg, October 1992
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* Introduction to PPM South *
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0 Preface
=======
0 The idea of this introduction to PPM South is to deliver a short
explanation together with the catalogue itself. It briefly
describes the way in which PPM South was constructed and the
contents of the catalogue on magnetic tape. It should not be
understood as a detailed description of the work performed in the
construction of the catalogue. This will be given in a
forthcoming paper (Roeser et al., 1993).
-
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0 Contents
========
- 1. Scope of PPM South 3
2. Construction of the catalogue 4
3. Properties of PPM South 8
4. Practical usage of PPM South 12
5. List of Critical Comments on Individual Stars 13
6. List of Remarks on Individual Stars 18
7. Explanation of the machine-readable version 20
0 References 23
Acknowledgements 25
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1. Scope of PPM South
=====================
0 PPM South gives positions and proper motions of 197179 stars
south of about -2.5 degrees declination. Its main purpose is to
provide a convenient, dense and accurate net of astrometric
reference stars on the southern celestial hemisphere. This net is
designed to represent as closely as possible the new IAU (1976)
coordinate system on the sky, as defined by the FK5 star
catalogue (Fricke et al., 1988). In other words, it is a
representation of this system at higher star densities and
fainter magnitudes.
0 Until recently the SAO Catalogue served the same purpose. There
are three major reasons to replace SAOC now:
0 1) SAOC is a representation of the now obsolete FK4 system of
positions and proper motions. Astronomers should have a direct
access to the FK5 system.
0 2) The accuracy of positions and proper motions in SAOC is no
longer satisfactory. Astronomers should have a more accurate
tool. Over more than a century astrometrists have accumulated a
vast treasure of measured star positions. The fact that much of
this treasure is now available in machine-readable form and the
power of present-day computers make it easy to analyse and
combine this amount of data.
0 3) Proper motions in SAOC were derived from only two separate
source positions per star. This lack of redundancy lead to a
large number of coarse errors in that catalogue. With more than
two measurements per star such errors can be largely avoided. In
this way astronomers now get a more reliable astrometric tool.
0 PPM South is the southern-hemisphere complement to the PPM Star
Catalogue (Roeser and Bastian, 1991), which covers the northern
hemisphere, plus a strip between the equator and about -2.5
degrees declination. At the border line a continuous transition
between the northern and southern part was tailored in such a way
that no overlap, nor gaps, nor double entries occurred.
0 The star density of PPM South is slightly higher than that of its
northern counterpart. The accuracy of the present-epoch positions
is roughly twice that in the north. In fact, all of PPM South is
as precise as the "High-Precision Subset" of PPM (north). So, for
the first time in the history of astronomy, the practical
coordinate system is denser and more precise on the southern than
on the northern hemisphere.
0 Compared to SAOC the mean star density is higher by a factor of
1.5, but between the equator and -20 degrees declination it is
higher by a factor of 2. The accuracy of present-epoch positions
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and proper motions is higher by a factor of 6 to 10, depending on
declination.
0 The high present-epoch accuracy of PPM South is due to the
inclusion of the recently completed FOKAT-S and CPC-2 catalogues.
FOKAT-S (Yagudin et al., 1993) is a fourfold coverage of the
southern sky, photographed around 1984 in a Soviet-Bolivian
cooperation. CPC-2 (Zacharias et al, 1992) also is a fourfold
coverage of the southern sky, photographed around 1966 at the
Cape of Good Hope.
0 The data files following this Introduction to PPM South are
analogous and complementary to the resp. files of PPM (north).
Combining the corresponding files will provide the user with a
catalogue of 378910 reference stars on the whole sky.
-
-
2. Construction of the catalogue.
=================================
0 The construction of the catalogue proceeded in much the same way
as described in the Introduction to PPM (north). Only few, yet
important changes to that procedure were made, and will be
mentioned below.
- Step 1: Compilation of the star list.
0 The star list for PPM South was constructed starting from the
preliminary version of FOKAT-S (Bystrov et al., 1989) which
contains 203135 stars. All stars of FK5 (Basic FK5 plus Bright
Extension), SRS and SAOC south of -2.5 degrees declination were
added, if not already included. In the course of the work a few
thousand stars had to be deleted (because either they are
non-existent or already in PPM North, or else have no
satisfactory observational history). On the other hand, a number
of close companions to FOKAT-S stars and a small list of stars of
special interest were added. This gave the final list of 197179
stars.
- Step 2: Identification of stars in the source catalogues
0 The complete list of source catalogues is given in Chapter 3,
below, along with an explanation of their abbreviations, with
bibliographic references and some statistics.
0 The stars in each of the source catalogues were identified with
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the objects of the star list. This was done in a fully automatic
process. Problem cases recognized in this process were
investigated manually to detect typing errors in the source
catalogues, to correctly identify double star components, to
avoid the effect of grossly incorrect positions in the star list
etc.
0 Prior to the identification of Astrographic Catalogue data (given
as original x,y plate coordinates) a plate reduction had to be
performed, see step 4, below.
- Step 3: Construction of a preliminary system of positions and
proper motions.
0 A preliminary system of positions and proper motions is necessary
to eliminate systematic deviations between the individual source
catalogues. For this purpose we used the SRS catalogue (Smith et
al., 1989) with the preliminary proper motions given there.
Nominally it is a representation of the FK4 system. For
observational epochs before 1920 this turned out to be too sparse
and too inaccurate. Therefore the GC (Boss, 1936) was added,
after removal of the systematic deviations between SRS and GC,
both in positions and proper motions.
- Step 4: Reduction of source catalogues to the preliminary system
0 Zonal systematic deviations as well as magnitude- and colour-de-
pendent systematic deviations between each of the source
catalogues and the preliminary system were determined and
eliminated. The zonal corrections were done by a two-dimensional
moving-average filter technique, as sketched by Roeser (1990).
0 For the reduction of the Astrographic Catalogue plates an
intermediate compilation catalogue of 144 787 stars was
constructed from all source catalogues except AC. Two versions of
it were published as "Preliminary PPM South" (Bastian et al.,
1990) and "Preliminary PPM South, Version 4/91" (on the CD-ROM of
NASA's Astronomical Data Center, 1991). But even with this
catalogue it was not possible to fully exploit the high inherent
quality of the raw AC data in a normal single-plate astrometric
reduction.
0 A three-stage procedure was applied, therefore:
- 1) A first-order single-plate reduction is performed. The
resulting celestial coordinates are used to cross-identify the
stars on overlapping plates.
- 2) A first-order plate-overlap solution follows as second
stage. Each plate is connected to all immediately overlapping
plates. This gives a more rigid and more precise plate-to-sky
transformation. The accuracy of the resulting celestial
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coordinates is no longer dominated by the reference catalogue,
but by the inherent accuracy of the plate measurements.
- 3) The residual differences, both to the reference catalogue
and to the overlapping plates, are investigated thoroughly.
Systematic defects of the measured plate coordinates (such as
magnitude equations, higher-order distortions, coma, or colour
equations) can be detected and corrected in this way. If
necessary, stages 2 and 3 were repeated.
- Step 5: Determination of weights for the source positions
0 In any least-squares adjustment, weights have to be assigned to
individual measurements, according to their mean errors.
Magnitude-dependent mean errors of the positions were determined
for each source catalogue. Different approaches were used,
according to need. The following paragraph gives but a few
examples.
0 For early-epoch catalogues the mean errors were preferentially
taken from Eichhorn (1974). However, investigation of the Yale
zone catalogues yielded that some of them, especially the latest
ones, were in fact much better than estimated by Eichhorn. For
the Carlsberg Meridian Circle catalogues (CMC 1985-1991) the
differences to FK4 were investigated by R. Bien (1988).
Extrapolation to fainter magnitudes was possible using
information given within the CMC catalogues. For Astrographic
Catalogue zones the differences between positions of the same
star measured on different (overlapping) plates were
investigated. For SRS the mean errors given by its authors
(Smith et al. 1989) were used, with some modification for the
bright stars.
0 All weights were chosen to be conservative estimates, in order to
ensure that the accuracy of PPM South will not be overestimated.
- Step 6: Least-squares adjustment
0 A standard weighted least-squares adjustment of the mean
positions and proper motions was performed for each star -
separately for right ascensions and declinations. Automatic tests
for unduly large scatter among the measurements (based on the
chi-square sum) and automatic elimination of obvious outliers
(based on appropriately normalized individual residues) were
implemented. All stars having bad chi-square sums beyond a
certain significance limit, but still not showing obvious
outliers, were marked as "problem cases" (see flag 'P' in
byte 127 of the machine-readable catalogue). This occurred in
about 1500 cases.
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Step 7: Manual treatment of difficult cases
0 The automatic outlier elimination deleted about 9000 measured
coordinates (out of more than 2.5 million). Tight restrictions
however, were imposed on this automatic process in order to avoid
spuriously "good" results. This created almost 1000 "difficult
cases" that were treated manually. A majority of these turned out
to be coarse errors in the source catalogues, mixed-up double
star components etc. For about 200 objects no satisfactory
solution could be found. These were added to the "problem cases"
of step 6, giving a total of 1724 PPM stars with flag 'P'.
- Step 8: Transformation from the preliminary to the final system
0 The positions and proper motions derived so far had to be
transformed from the preliminary system (described above) to the
new IAU (1976) coordinate system, as defined by FK5.
0 Comparison of our preliminary system with final IRS (Corbin
1991), on the system of FK4, showed that there were almost no
relevant differences. The sole exception are the proper motions
in right ascension south of -70 degrees declination.
Incidentally, however, the preliminary SRS system is closer to an
undisturbed sphere than the final IRS system for present epochs.
This follows from the comparison of preliminary PPM South with
provisional HIPPARCOS results (Lindegren, 1992).
0 Therefore we decided to apply no changes at all to the
preliminary system. The plots of Lindegren (1992) thus give a
good indication of the regional deviations of the PPM system from
a perfect coordinate sphere for present epochs. They also show
that the PPM system is indeed very close to the FK5 system, both
on the southern and on the northern celestial hemisphere.
0 The transition from FK4 system to FK5 system followed exactly the
same procedure as was used in the construction of FK5 (Fricke et
al., 1988).
- Step 9: Introduction of FK5 data for FK5 stars
0 For the stars contained in FK5 Part I (the Basic Fundamental
Stars) and in FK5 Part II (the Bright Extension Stars), PPM gives
the original FK5 data. These were introduced by simply copying
them from the machine-readable version of FK5.
- Step 10: Provision of cross-references and auxiliary data
0 In addition to the astrometric data PPM gives cross-references to
other star catalogues, magnitudes, spectral types and a number of
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flags for each star.
0 Cross-references were determined by different methods, ranging
from direct cross-identification (based on positions only) to
simply copying historic work done by others (in the cases of
catalogues having low positional accuracy such as DM and HD).
Cross-references are given explicitly for six catalogues: Bonner
Durchmusterung and Cordoba Durchmusterung (abbreviated DM), SAO
Catalogue, Henry Draper Catalogue (HD) and Cape Photographic
Durchmusterung (CPD). Three more cross-references are given
implicitly by flags (see chapter 7, explanation of the
machine-readable version):
0 Flag 'F' in byte 130 denotes the stars contained in FK5 (Part I
plus the Bright Extension).
0 The double star flag 'D' (byte 128) was created by
cross-referencing PPM with the Catalogue of Components of Double
and Multiple Stars (Dommanget, 1988).
0 The magnitudes given are mostly V magnitudes, copied from CPC-2.
They are indicated by flag 'V' in byte 131. V magnitudes from FK5
are given for the FK5 stars (flag 'F'). The magnitudes for the
remaining 33 000 stars of PPM South are an inhomogeneous
collection from various sources.
0 The majority of spectral types are HD data. Again, FK5 data were
copied for FK5 stars.
0 Various sorts of auxiliary information are given in the List of
Critical Comments and in the List of Remarks (see Chapters 5 and
6) and indicated by the 'C' and 'R' flags.
-
-
3. Properties of PPM South
===========================
-
Random errors
+ _____________
0 The table below shows a summary of the error budget of PPM South.
Each line of the table gives the following data for different
declination zones: The number of stars in the zone, the average
number of source positions per star, the average number of stars
per square degree, the average of the mean epochs (for right
ascension and declination), the average of the mean errors of
proper motion (for right ascension and declination) and the
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average of the mean errors of position at epoch 1990 (again for
right ascension and declination). Units are seconds of arc and
seconds of arc per century, respectively. At the bottom of the
table the corresponding values for SAOC are given for comparison.
0 Note that the accuracy of all PPM South is as high as that of the
High-Precision Subset of PPM (north).
-
Table 1: Error budget of PPM South
0 Zone No. No. Dens. mean ep. mean err. mean err.
stars obs. /sq.d. 1900+ prop. mot. pos. 1990
0 -2.5- -20 60657 5.6 10.2 62.3 62.1 0.28 0.28 0.11 0.11
-20 - -40 62048 6.6 10.3 63.8 62.4 0.32 0.31 0.11 0.11
-40 - -60 47121 5.8 10.5 60.5 60.4 0.31 0.32 0.12 0.12
-60 - -90 27353 7.0 10.2 58.6 60.9 0.27 0.30 0.11 0.11
0 total 197179 6.1 10.3 61.8 61.6 0.30 0.30 0.11 0.11
0 SAOC,south 126000 2.0 6.5 30 30 1.5 1.5 1.2 1.2
- Note that (on average) more than 6 measured positions are
available per star. This redundancy allowed us to discover (and
avoid) a large number of gross errors in the source catalogues.
It ensures that PPM South contains very few coarse errors for
stars with 4 or more positions (more than 90 percent of all
stars). For 1801 PPM South stars the redundancy was not
sufficient to resolve discrepancies between the source positions.
They are indicated as unreliable by the 'P' or 'C' flags
mentioned above. We kept these stars in PPM South, because for
the majority of them the PPM data will still be correct to a few
tenths of an arcsec. And even the rest will be within a few
arcsec at most.
-
Source catalogues
+ _________________
0 More than 1 250 000 source positions (i.e. right ascensions and
declinations) entered into the least-squares adjustments for PPM
South. The following table lists the various groups of source
catalogues used and the total number of positions taken from each
group. More information on many of the catalogues as well as
bibliographic references are given in the book by Eichhorn
(1974).
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Table 2: Source Catalogues
0 Astrographic Catalogue 482 000
FOKAT-S 203 000
CPC-2 172 000
Yale zone catalogues 128 000
"AGK1" 126 000
CPC 62 000
Sydney SSC 22 000
CMC4, CMC5 20 000
SRS 19 000
Perth Cat. of Astrogr. Ref. St. 9 000
Melbourne Gen. Cat. 3 to 5 8 000
0 Total 1 251 000
0 Here, "AGK1" stands for the different catalogues of the "Catalog
der Astronomischen Gesellschaft, Zweite Abtheilung" and its South
American extension, the catalogues Cordoba A to D and La Plata A
to F.
- Numbering.
+ __________
0 The assignment of running numbers to the stars is a straightfor-
ward continuation of that for PPM (north). It starts with number
181732 for the first star and ends with number 378910. As in PPM
(north) the stars are arranged in bands of 10 degrees width in
declination. Within each of these bands they are ordered
according to right ascension. This arrangement was also used in
the SAO Catalogue.
0 As a side remark we mention that in Preliminary PPM South the
stars had running numbers starting with 500001. This was to
ensure that no confusion with the final PPM number can arise.
Furthermore, it ensures that any data taken from the preliminary
catalogue can be easily recognized as such.
-
Systematic Errors
+ _________________
0 We did our very best to ensure that PPM is on the system of FK5.
Such a goal, however, can be reached to a certain accuracy only.
We estimate that the residual systematic deviations between PPM
South and the FK5 system have a typical size of 0.05 arcsec for
the positions at mean epoch and of 0.2 arcsec per century for the
proper motions.
0 These numbers do not hold, however, for a few special groups of
objects: The very blue stars (spectral types B2 and earlier), the
very faint stars (fainter than about 11.5 in photographic
magnitude) and those very bright stars (brighter than about 7)
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that are not in FK5. Because these groups are very small by
number it was neither possible to check our preliminary system to
the desired accuracy, nor could we correct the individual source
catalogues to this system with the desired accuracy. So we just
do not know anything about possible systematic errors for these
small groups.
-
Missing bright stars
+ ____________________
0 PPM and PPM South are not intended to be an inventory of the sky,
but to provide a practical coordinate system on the sphere. This
is why no special efforts were taken to make them complete to
some limiting magnitude. Nevertheless, it would clearly be
advantageous if all bright stars were included. We plan,
therefore, to produce a supplementary star list, containing the
few hundred objects brighter than magnitude 8.0 which are missing
now.
-
Some Statistics
+ _______________
0 PPM South gives 125 420 SAOC numbers. This corresponds to more
than 99 percent of all SAOC stars in the celestial region covered
by PPM South. It gives 121 817 HD numbers, corresponding to
roughly 75 percent of all HD stars in the region. 190 061 stars
carry either a BD or a CoD number, 136 586 stars have a CPD
number and 151 018 have a spectral type.
0 There are 12 376 double star flags ('D'), 1724 problem cases ('P'
flags), 77 critical comments ('C' flags) and 33 less important
remarks ('R' flags). The 'R' flags refer to double star
companions and to variable stars mostly. They are not in any way
intended to be exhaustive or complete.
0 The number of FK5 stars ('F' flags) in PPM South is 1160. In
passing, we note that in PPM (north) inadvertantly no 'F' flags
and no FK5 data were given for two stars: FK5 3942 = PPM 161 and
FK5 1270 = PPM 178197.
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4. Practical usage
==================
0 PPM South gives positions for a standard epoch (J2000) and a
standard coordinate system (mean equator and equinox for J2000 in
the new IAU (1976) system of astronomical constants.
0 To apply the catalogue as astrometric reference at a different
observational epoch, but still in the J2000 coordinate system,
proper motions must be taken into account. For most purposes a
simple linear formula (position difference equals epoch
difference times proper motion) is sufficient. But note that this
procedure will give inaccurate results close to the pole. Better
formulae are given e.g. by Murray (1983) and in the introduction
to FK5.
0 To apply PPM South as astrometric reference for a different
equator and equinox, but still in the IAU (1976) system of
astronomical constants, precession has to be taken into account.
The relevant formulae and numerical values are given e.g. by
Lieske (1979) and in the introduction to FK5.
0 Note that simply precessing from J2000 to B1950 will still not
give results in the old (FK4) astronomical coordinate system.
This differs from the new IAU (1976) system by a correction to
the precessional constant, a correction to the position of the
vernal equinox, by the treatment of elliptical aberration and by
complicated zonal corrections. In general, this adds up to about
an arcsec in position and several tenths of an arcsec per century
in proper motion. In the region between -60 and -80 degrees
declination the difference between the FK4 and the FK5 system is
especially large. It amounts to 1.6 arcsec in right ascension at
epoch 2000, and to about 1 arcsec/century for the proper motion
in right ascension.
0 In File 3 of the machine-readable version we therefore publish
positions and proper motions for equinox and epoch B1950 on the
system of FK4, as we did for PPM (north).
0 Application of proper motion and precession still gives mean
positions. In order to derive apparent positions for PPM objects
one has to apply nutation, aberration, stellar parallax, and
relativistic light bending, in addition (see e.g. Murray, 1983).
For most practical uses of PPM these effects can be ignored. But
PPM South contains a small number of stars with fairly large
parallaxes. They are not indicated in the catalogue.
0 For each star PPM South gives mean errors for right ascension and
declination at their respective mean epochs T. Standard error
propagation calculus can be used to calculate the mean error PPM
position for an epoch t different from the mean epoch: Denoting
the mean error of one coordinate at mean epoch by E(T), the mean
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error of proper motion by E(PM), the mean error of position at
epoch t is given by
0 2 2 2 2
E(t) = E(T) + E(PM) * (T-t)
0 Using more PPM stars in an application will usually give better
results because of the partial cancellation of the purely
accidental errors of the PPM data. However, this improvement
will never get beyond the systematic errors of PPM, as discussed
in the previous chapter.
-
-
5. List of Critical Comments on Individual Stars
================================================
0 The following list gives, for each star included: The PPM number
and a critical comment.
0 All stars included in this list carry the 'C' flag. Their
astrometric data should be regarded as unreliable.
- 187259 See remark to PPM 187260.
0 187260 Double star. Companion is PPM 187259. Components
may be mixed up.
0 198815 Northern component of ADS 9728. Proper motion
derived from 3 positions around 1900 and a re-
constructed one for the CPC-2 epoch. The position
of this star in Yale16 is wrong. CPC-2 contains
the southern component in duplicate.
0 206258 Seems to be double. Probably there is another
star a few arcsec to the south east.
0 209551 Double star SAO 147542 / SAO 147543. Components
possibly mixed up in photographic source
catalogues.
0 218925 Double star, photographic source catalogues
measured combined image.
0 219535 Western component of a 3 arcsec double. SAO data
grossly wrong due to mixing of components.
0 220938 Companion to PPM 220939
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0 220939 Companion to PPM 220938. Not properly resolved
in the photographic source catalogues.
0 221658 Double star ADS 7423. Bright component is SAO
155267. Fainter companion, about 9 mag, 5 arcsec
to the south. Not properly resolved in the
photographic source catalogues.
0 222456 Double star. Companion is PPM 222457.
Components may be mixed up.
0 232367 Double star. Companion is SAO 160197.
Components may be mixed up.
0 236431 Seems to be double, with a separation of 2 to 3
arcsec.
0 240280 Double star SAO 165078 / SAO 165077. Components
possibly mixed up in photographic source
catalogues.
0 241502 Double star ADS 16688. Separation around 5
arcsec. All photographic source catalogues
measured a combined image.
0 252684 Double star. Companion is PPM 252685. Components
may be mixed up.
0 252685 Double star. Companion is PPM 252684. Components
may be mixed up.
0 252900 Close companion to SAO 174237. SAO 174237 is not
in PPM, is about 1 mag brighter than PPM 252900 and
situated about 5 arcsec to the north of PPM 252900.
0 254989 Seems to be double. Separation 3 to 4 arcsec.
SAO proper motion grossly wrong.
Components mixed up in the source catalogues.
0 259116 Double star. Companion is PPM 259117. Components
may be mixed up.
0 259117 See remark to PPM 259116.
0 261849 Double star, photographic source catalogues
measured combined image.
0 263277 South-eastern component of a 4 arcsec pair
having roughly equal magnitudes.
0 263375 Double star. Companion is PPM 263376. Components
may be mixed up.
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0 263376 Double star. Companion is PPM 263375. Components
may be mixed up.
0 265426 Double star. Companion is SAO 159864. Components
may be mixed up.
0 266532 May be double. Suspected separation 2 to 3 arcsec
in right ascension.
0 266613 Double star. Companion is SAO 185199. Components
may be mixed up.
0 268784 Double star. Companion to PPM 268785. SAO 187168.
SAO data wrong due to mixing of components.
0 268785 Double star. Companion to PPM 268784. SAO 187168.
SAO data wrong due to mixing of components.
0 268984 Double star. Companion is PPM 268985. Components
may be mixed up.
0 268985 See remark to PPM 268984.
0 275452 Double star. Companion is SAO 192230. Components
may be mixed up.
0 278376 Double star. Companion is SAO 193927. Components
may be mixed up.
0 283089 Double star. Companion is SAO 197176. Components
may be mixed up.
0 283868 Double star. Companion is PPM 283869. Components
may be mixed up.
0 283869 See remark to PPM 283868.
0 286548 This is SAO 200445, the brighter, north-eastern
component of a double. The companion is
SAO 200444. Separation about 8 arcsec.
0 286920 Double star. Companion is SAO 200759. Components
may be mixed up.
0 291906 Double star, photographic source catalogues
measured combined image.
0 293743 Double star. Companion is SAO 206544. Components
may be mixed up.
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294532 Double star. Companion is PPM 294533. Components
may be mixed up.
0 294533 See remark to PPM 294532.
0 294735 Double star. Companion is PPM 294737. Components
may be mixed up.
0 294872 Double star. Companion is SAO 207516. Components
may be mixed up.
0 297036 Double star Co 222. Magnitudes 8 and 9, separation
about 3.5 arcsec in p.a. 120 degrees. Photographic
source catalogues measured combined images.
0 297085 Double star, photographic source catalogues
measured combined image
0 297133 Seems to be double, with a separation of 2 to 3
arcsec.
0 298436 See remark to PPM 298437.
0 298437 Double star. Companion is PPM 298436. Components
may be mixed up.
0 310971 Double star. Companion is PPM 310972. Components
may be mixed up.
0 310972 Double star. Companion is PPM 310971. Components
may be mixed up.
0 312674 Double star. Companion is SAO 219509. Components
may be mixed up.
0 313226 Double star, identity of components unclear.
Therefore the proper motion, both in PPM and
in SAO, may be wrong.
0 314660 Double star. Companion is SAO 221478. Components
may be mixed up.
0 320653 Double star. Companion is SAO 225845. Components
may be mixed up.
0 322346 See remark to PPM 322347.
0 322347 In star cluster NGC 6231.
Double star. Companion is PPM 322346. Components
may be mixed up.
0 323229 Double star. Companion is SAO 228247. Components
may be mixed up.
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0 323811 See remark to PPM 323812.
0 323812 Double star. Companion is PPM 323811. Components
may be mixed up.
0 326265 Double star. Companion is SAO 230259. Components
may be mixed up.
0 328272 Double star, the companion is PPM 328273.
Not well separated, some photographic
source catalogues measured combined images.
0 328273 See remark to PPM 328272.
0 330419 Seems to be a close double, components mixed up.
0 335814 Double star. Companion is PPM 335815. Components
may be mixed up.
0 335815 See remark to PPM 335814.
0 339408 Eta Carinae complex
0 342157 Double star. Companion is SAO 241075. Components
may be mixed up.
0 343102 Double star. Companion is SAO 241950. Components
may be mixed up.
0 345433 Double star. Companion is SAO 227281. Components
may be mixed up.
0 350797 Double star Dunlop 246, SAO 247739 and SAO
247738. Magnitudes 6 and 7, separation about
9 arcsec in p.a. 260 degrees. Photographic
source catalogues measured combined images.
0 352179 Double star. Companion is PPM 352180. Components
may be mixed up.
0 352180 Double star. Companion is PPM 352179. Components
may be mixed up.
0 354885 30 Doradus nebula and cluster, NGC 2070
0 358676 Double star. Companion is SAO 251382. Components
may be mixed up.
0 367144 Globular cluster Dunlop 62, NGC 362.
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-
- 6. List of Remarks on Individual Stars
======================================
0 The following list gives, for each star included: The PPM number
and a remark. In contrast to the Critical Comments these remarks
are not of direct relevance to astrometry.
0 All stars included in this list carry the 'R' flag.
0 184482 Omikron Ceti, 2-10 mag
0 188303 Sigma Ori A, 4.0-6.0 mag
0 191848 T Hya, 7.3-13.8 mag
0 198814 Southern component to PPM 198815. 5 measured
positions, somewhat discordant in declination.
0 218852 Spectral type K5 + M3ep
0 219584 Northern component of ADS 6553. Companion of
similar brightness 5 arcsec to the south.
0 223226 U Hya, 4.8-5.9 mag
0 223323 The cross-identifications given are from SIMBAD
data base. But according to SAOC this star is
BD -13 3193 = HD 92677.
0 225675 R Crv, 5.9-14.0 mag
0 236273 Double star ADS 12699; a fainter companion
lies about 5 arcsec to the north west.
0 239702 Double star. The companion is SAO 164830,
about 5 arcsec to the north east.
0 243352 Double star. Companion is SAO 166652, 5 arcsec
to the north.
0 259064 SAO 179935, brighter component of double ADS 8183.
The fainter component is PPM 259065.
0 259065 Companion to PPM 259064 = SAO 179935.
SAO data grossly wrong due to mixing of components.
0 283489 Double star. Companion is SAO 197558.
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0 295347 SU Sco, 11.5-14 mag
0 311594 variable, 3.4-6.2 mag
0 320951 Double star. Companion is SAO 226131.
0 321275 Double star. Companion is SAO 226443.
0 329505 Double star. Companion is SAO 231718.
0 339070 YZ Car, 9.0-10.7 mag
0 339090 UX Car, 8.1-9.1 mag
0 339405 SV Vel, 8.8-10.8 mag
0 344085 U Nor, 8.6-9.2 mag
0 349722 Double star. Companion is SAO 247198.
0 352298 Double star. Companion is SAO 248345.
0 354005 Double star. Companion is SAO 248985.
0 356979 SAO proper motion for this star is grossly wrong.
0 357553 Double star. Companion is SAO 250696.
0 358986 Southern component of an 8 arcsec pair.
0 359025 UU Mus, 9.4-10.3 mag
0 365147 Y Pav, 5.7-8.5 mag
0 377688 Double star. Companion is SAO 257158.
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7. Explanation of the machine-readable version of PPM South
===========================================================
0 The machine-readable version of PPM South contains 3 physical
files.
0 The three files are:
0 - File 1: The text of this introduction to PPM South
0 - File 2: The catalogue as an easily readable table, 197179 records,
in the same format as PPM (north).
0 - File 3: The catalogue in the format in which the preliminary
version of PPM (north) was delivered in 1988.
0 The remainder of this chapter gives very short descriptions of
these three files. It describes the formats of the files together
with a short description of the contents.
- The tables defining the individual files give the following
information for each data item:
0 - name of the item (mnemonic)
- position of the item within each record (first and last byte)
- FORTRAN format
- explanation
- maybe a remark
0 In addition there is information on record length etc. at the top
of each table.
- File 1: The Introduction to PPM South
+ _____________________________________
0 This is a text file, given in exactly the same format as the
printed Introduction to PPM South. Record length is 133 bytes,
but only 76 bytes are actually used (the remaining being always
blank). This file can be used to produce printed versions of the
introduction on any printer able to interpret the paper feed
characters '1' (form feed), ' ' (single line feed), '0' (double
line feed), '-' (triple line feed) and '+' (no line feed). Page
headings, page numbering etc. appear as in the printed
introduction. Just submit the file to your printer. The printed
pages contain 66 lines at maximum.
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-
File 2: PPM South as an easily readable table
+ _____________________________________________
0 This is the main file giving the catalogue proper. Record length
is 133 bytes. The stars are arranged in bands of 10 degrees width
in declination. Within each of these bands they are ordered
according to right ascension. This arrangement was also used in
the SAO catalogue. You can use this file to produce a rough
printed version of PPM South by just submitting it to a printer
capable of printing 133 characters per line. No page headings,
form feed characters etc. are included, of course.
0 PPM 2 - 7 I6 designation of the star in PPM South
starting with No. 181732, see chapter 3.
DM 10 - 18 A9 designation of the star in the Bonner
Durchmusterung (for zones from -02
to -22 degrees) or in the Cordoba Durch-
musterung (zones -23 to -89 degrees).
Mag 20 - 23 F4.1 magnitude, see chapter 3.
Sp 25 - 26 A2 spectral type, see chapter 3.
R.A. 28 - 39 F2.0,1X,F2.0,1X,F6.3
Right Ascension for the equinox and epoch
J2000.0, on the system of FK5, given in
hours, minutes and seconds of time.
Sign 42 - 42 A1 Sign of declination ('+' or '-').
Dec. 43 - 53 F2.0,1X,F2.0,1X,F5.2
Declination for the equinox and epoch
J2000.0, on the system of FK5, given in
degrees, minutes and seconds of arc.
PMA 56 - 62 F7.4
proper motion in right ascension for epoch
and equinox J2000.0, on the system of FK5,
given in seconds of time per Julian year.
PMD 64 - 69 F6.3
proper motion in declination for epoch and
equinox J2000.0, on the system of FK5,
given in seconds of arc per Julian year.
N 71 - 72 I2
number of individual published positions
used for the derivation of the position
and proper motion given
SA 74 - 75 F2.0
mean error of right ascension at the mean
epoch of right ascension, multiplied by the
cosine of declination, given in units of
0.01 seconds of arc.
SD 77 - 78 F2.0
mean error of declination at the mean epoch
of declination, given in units of
0.01 seconds of arc.
SPMA 80 - 83 F4.1
mean error of the proper motion in right
ascension, multiplied by the cosine of
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declination, given in units of 0.001 seconds
of arc per Julian year
SPMD 85 - 88 F4.1
mean error of the proper motion in declination
given in units of 0.001 seconds of arc per
Julian year
EPA 90 - 94 F5.2
weighted mean epoch of the measured positions
used for the derivation of R.A. and PMA,
given in years since 1900.0
EPD 96 - 100 F5.2
weighted mean epoch of the measured positions
used for the derivation of Dec. and PMD,
given in years since 1900.0
SAO 102 - 107 I6 designation of the star in the SAO
Catalogue
HD 109 - 114 I6 designation of the star in the Henry
Draper Catalogue
CPD 117 - 125 A9 designation of the star in the Cape
Photographic Durchmusterung
Flags 127 - 131 5A1 Five flags - possible values:
127 P problem case, preferably not to be
used as astrometric reference star.
127 C a critical comment is given in the
List of Critical Comments. Not to be
used as astrometric reference star.
128 D double star, preferably not to be
used as astrometric reference star.
129 - Not used, void for consistency with
PPM (north).
130 F member of FK5, mostly bright stars,
original FK5 data are given.
131 R a remark is given in the List of
Remarks on Individual Stars.
131 V the magnitude is a photographic V
magnitude copied from CPC-2.
0 Be careful not to miss the sign of the declination (byte 42)
while transforming this formatted file into a numeric file on
your computer.
- File 3: The catalogue in the format of the preliminary PPM
+ __________________________________________________________
0 File 3 gives a version of PPM South for equinox and epoch
B1950.0, FK4 system (see items RA50, Dec50, PMA50 and PMD50 in
the table below). It contains the J2000.0 version also. This file
was added for the convenience of those users that received the
preliminary PPM (north) on tape. To transfer File 3 to their home
computer they can use exactly the same reading routine as for the
preliminary PPM (north).
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-
Record length is 138 bytes.
0 2 - 4 A3 3 characters 'PPM'
PPM 5 - 10 I6
Mag 11 - 16 F6.1
Sp 19 - 20 A2
Flag 22 - 22 A1 problem flag, see description of File 2,
byte 127
RA50 24 - 38 D15.8 radians
Right ascension for equinox and
epoch B1950, FK4 system
Dec50 40 - 54 D15.8 radians
Declination for equinox and epoch
B1950, FK4 system
PMA50 56 - 67 D12.5 radians/tropical century
Proper motion in R.A. for equinox and
epoch B1950, FK4 system
PMD50 69 - 80 D12.5 radians/tropical century
Proper motion in Dec. for equinox and
epoch B1950, FK4 system
R.A. 82 - 96 D15.8 radians
Right ascension for equinox and
epoch J2000, FK5 system
Dec. 98 - 112 D15.8 radians
Declination for equinox and
epoch J2000, FK5 system
PMA 114 - 125 D12.5 radians/julian century
Proper motion in R.A. for equinox
and epoch J2000, FK5 system
PMD 127 - 138 D12.5 radians/julian century
Proper motion in Dec. for equinox
and epoch J2000, FK5 system
-
-
References.
===========
0 Boss, B. (1936): General Catalogue of 33342 Stars for the Epoch
1950. Vols. I to V. Carnegie Institution of Washington,
Washington 1936.
0 Bystrov, N.F., Polozhentsev, D.D., Potter, Kh.I., Zalles, R.F.,
Zelaya, J.A. and Yagudin, L.I. (1989): On the
FOKAT catalog. Astron. Zh. 66, 425.
0 CMC (1985-1991): Carlsberg Meridian Catalogue La Palma,
Numbers 1 to 5. Copenhagen University Observatory,
Royal Greenwich Observatory and Real Instituto y
1
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Observatorio de la Armada, San Fernando.
0 Corbin, T. (1991): International Reference Stars Catalog,
Washington, US Naval Observatory, 1991.
0 Eichhorn, H. (1974): Astronomy of Star Positions, Frederick
Ungar Publ. Co., New York.
0 Fricke, W., Schwan, H., Lederle, T. (1988): Fifth Fundamental
Catalogue (FK5). Part I. The Basic Fundamental Stars.
Veroeff. Astron. Rechen-Institut Heidelberg Nr.32.
0 IAU (1976): IAU Transaction XVI B, Reidel Publ., Dordrecht 1977.
0 Lieske, J. (1979): Precession matrix based on IAU(1976) system
of astronomical constants, Astron. Astrophys. 73, 282.
0 Murray, C.A. (1983): Vectorial Astrometry, Adam Hilger Ltd.,
Bristol, UK.
0 Roeser, S. The System of the PPM Catalogue. Proc. IAU-Symp. 141
Inertial Coordinate System on the Sky. Ed.: J.H. Lieske
and V.K. Abalakin. p. 469. Kluwer,Dordrecht, 1990.
0 Roeser, S., Bastian, U. (1991): PPM Star Catalogue, Astronomi-
sches Rechen-Institut, Heidelberg, Vols. I and II, printed
by Spektrum Akademischer Verlag, Heidelberg
0 Roeser, S. et al. (1993): The Construction of PPM South, in
preparation.
0 Smith, C.A., Corbin, T.E. Hughes, J.E., Jackson E.S.,
Khrutskaya, E.V, Polozhentsev, A.D., Polozhentsev, D.D,
Yagudin, L.I., Zverev, M.S. (1989): The SRS catalog
of 20488 star positions: culmination of an international
cooperative effort, in: IAU Symp. No. 141, Inertial
Coordinate System on the Sky, Leningrad, Oct. 17-21,
1989.
0 Yagudin, L.I. et al. (1993): The FOKAT-S Star Catalogue, in
preparation.
0 Zacharias, N., de Vegt, C., Nicholson, W., Penston, M., 1992:
CPC-2 - the Second Cape Photographic Catalogue.
Astron. Astrophys. 254, 394.
1
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Acknowledgements
================
0 This work was supported by Deutsche Forschungsgemeinschaft,
Academy of Sciences of the USSR, Russian Academy of Sciences
and Ukrainian Academy of Sciences in the framework of the
collaboration project "Astrometric Star Catalogues".
0 We gratefully acknowledge help from our colleagues Wayne Warren,
Heiner Schwan, Maria Erbach and Eberhard Roehl.
© UDS/CNRS