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Explanation of Tables

Table 1: General list of PNe together with misclassified objects (according to galactic longitude)
PK designation: designation as in CGPN(1967) (see §2);
Name: name of the object as PN (see Table 7: Discovery Lists);
RA, DEC: rough coordinates (equinox 1950.0) having the accuracy 0.1$ ^{m}$, 1';
Discovery: discoverer of the object as PN (see Table 7: Discovery Lists) taken from CGPN(1967) (blank) or from S1-S6; discoverer of misclassified object (marked M) is given in parentheses; the supplement where the object was misclassified is also indicated.
Remarks: mainly independent discoveries, classif., identification, other names.

This general list contains not only real PNe (objects from Table 2), but also objects which were once classified as PNe but later removed from that list (objects from Table 3). The existing PK designation has been reserved for the given object only and is independent of its possible later new classification.

Table 2: List of PNe (according to right ascension)
PK designation (same as in Table 1);
Name (same as in Table 1);
RA, DEC: rough coordinates (equinox 1950.0) having an accuracy 0.1$ ^{m}$, 1';
Finding Charts: Plates Nos.1-119 (all objects given in S1-S6 and corrected charts of CGPN(1967));
RA, DEC: rough coordinates (equinox 2000.0) having an accuracy 0.1$ ^{m}$, 1';
PN G designation: taken from SECGPN or S1, also possible PNe and rejected objects from SECGPN, --not present objects;
Remarks: mainly different names for objects given in SECGPN or S1.

This is the actual list of PNe (till 1999). The name of the nebula is in most cases identical with the abbreviation of the person(s) who classified the object as a planetary nebula, or who gave the nebula his(their) own abbreviation. (For the abbreviations see Table 7: Index of discovery lists.) The exceptions are given in the CGPN(1967) or in the supplements.

There are 327 objects classified at present as ``possible planetary nebulae'' and denoted by * , added to the PK designation. These objects especially require further confirmation, which does not mean further observational data only, but also more precise theoretical consideration about what a planetary nebula is.
In the last column of this table and in the remarks the comparison with SECGPN is given. There are 63 objects included in this catalogue, which were rejected from SECGPN, and 101 objects which were classified there as possible planetaries. The objects rejected from SECGPN were mainly classified as symbiotic stars (n=35), peculiar em.-line stars (n=9) or they are objects where no em.-lines were observed (n=12). Our criteria for excluding objects from the list of PNe as SS are described in the former paragraph. As to the objects showing no em.-lines we are of the opinion that this situation is temporary only and that it may in principle change in the near future when better observational techniques will be used. On the contrary there are over 50 objects included in SECGPN and its S1 and not appearing in the main list of PNe in this catalogue. You can find a part of them as possible pre-PNe (Table 5) and possible post-PNe (Table 6). In general the difference between CGPN(2000) and SECGPN can be explained by the somewhat different classification criteria for PNe.

Table 3: List of misclassified PNe (according to right ascension)
PK designation (same as in Table 1);
Name (same as in Table 1);
RA, DEC: rough coordinates (equinox 1950.0) having an accuracy 0.1$ ^{m}$, 1';
Misclassified: in S1-S6;
Remarks: why the objects were misclassified.

This table contains objects once classified as PNe but removed from the list of PNe in S1-S6. In the remarks only rough reasons for misclassification are given; for more details see the corresponding supplement and the literature given there.

Table 4: Accurate coordinates of PNe (according to right ascension)
PK designation (same as in Table 1);
Name (same as in Table 1);
RA, DEC: accurate coordinates (for the given equinox) having an accuracy
(a) 0.01$ ^{s}$, 0."1 (b) 0.1$ ^{s}$, 1" (c) 1$ ^{s}$, 0.1'(mostly large objects);
Source: reference to the published literature or to the star catalogues;
Remarks: mainly concerning the individual coordinates and our measurements.

Many coordinates from the literature having accuracies (a) and (b) are listed in this table. For some objects only coordinates with the accuracy (c) were found in the literature; it is mainly a question of large nebulae without known and visible central stars. For about 800 objects the coordinates were improved (Kohoutek, Kühl, 1999) and measured on the Digitized Sky Survey with the accuracy (b) or exceptionally (c) for large objects. Let us mention that the coordinates given in various papers need not be independent of each other - the nature of the published coordinates was not indicated in all papers. Our aim was of course to use the original coordinates only.
Sometimes there are discrepancies in the individual coordinates. Larger discrepancies and probably typing errors are mentioned in the corresponding remarks.

The sources of coordinates can be divided into the following groups:
(a)  coordinates given already in CGPN(1967) (34 entries);
(b) coordinates from various papers 1969-1999 reported in Astronomy Astrophysics Abstracts (volume, paragraph, number); there is one paper which appeared between 1967 and 1969 and which was reported in AJB (Astronomisches Jahrbuch);
(c) coordinates given in the main catalogues (AC, AGK2, AGK3, GSC, HIPPARCOS, IRAS, LS, LSS, PPM, SAO).
As to the IRAS sources we distinguish three categories:
(a) sources which are identical with the optical objects (the difference between the optical and IRAS coordinates does not exceed about 20") - they are given in the main table;
(b) sources which are near the optical objects (the difference 20-60"). It is in principle possible that some of these IRAS sources are also identical with the optical objects, but the above difference exceeds the IRAS positional accuracy - such sources are given in the remarks;
(c) sources more than 60" away from the optical objects are not mentioned.

Table 5: Possible pre-PNe (according to right ascension)
Name;
RA, DEC: coordinates with various accuracies (equ. 1950.0);
Remarks and references.

The list of possible pre-PNe (n=334) contains objects being on the evolutionary way between late AGB stars and PNe. They are often IRAS sources with colours similar to PNe. Some of these objects are also called proto-PNe. This list is incomplete and the references give the orientation only; it does not appear in CGPN(1967).

Table 6: Possible post-PNe (according to right ascension)
Name;
RA, DEC: coordinates with various accuracies (equ. 1950.0);
Remarks and references.

The list of possible post-PNe (n=86) contains objects the central stars of which are on the evolutionary way between very old and large PNe and white dwarfs. This list is incomplete and the references give the orientation only; it does not appear in CGPN(1967).

Table 7: Index of discovery lists
This list gives the abbreviations of the names of the discoverers used for names of planetary nebulae in this catalogue (the catalogue CGPN(1967) as well as all supplements have been included).

We repeat - and this is our main rule - that that person is regarded as discoverer, who first denoted the object as a planetary nebula (and not who discovered the object generally).

The new planetary nebula receives the PK designation (given by the author of the catalogue), the IAU PN G designation (may be given by the discoverer himself) and the name, which is either
1) the common or generally used name of the object (NGC, IRAS, BD, ESO,...); or
2) the abbreviation of the name of the discoverer (or first two discoverers maximum) according to Table 7, and given by the author of the catalogue; or
3) the abbreviation or name proposed by the discoverer himself (sometimes the name from his internal list).

Our further main rule is that the discoverer receives only one single abbreviation which is the same in his different lists of planetary nebulae published in different papers. (Unfortunately there exist some exceptions mainly with regard to discoverer, to SECGPN or by error). Our procedure differs from that of SECGPN and its Supplement 1, where either different abbreviations appear for one discoverer (example: Weinberger - We, Wei, WKG - Weinberger, Kerber, Gröbner), or one abbreviation was given to different discoveres (example: St - Stephenson, 1978; StWr - Stock, Wroblewski, 1972; SwSt - Swings, Struve, 1940).


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Nächste Seite: Finding Charts Aufwärts: Contents Vorherige Seite: Objects Included and Omitted
Lubos Kohoutek
2001-04-02