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Discoveries

The first object called planetary nebula was named more than two centuries ago (NGC 6720; Ch. Messier, A. Darquier, 1779). Due to the work of W. Herschel altogether 13 PNe were known at the end of the 18th century. In addition, further 65 PNe were found in the 19th century.

A substantial increase of new PNe can be registered since 1945 as a result of spectral surveys and of Schmidt cameras. (About 90% of known PNe have been discovered since 1945.) In the last decade the slight increase of new PNe is mostly due to observations in no-visual regions (mainly in infrared) and due to the use of CCD cameras, which are more sensitive than photographic plates. The following catalogues or lists (partly mentioned already in CGPN(1967)) are given below.

The distribution of the number of PNe discoveries is given in the following figure:

hh001.ps

Fig.5  Dicoveries of PNe until 2000 in the respective decade.



Catalogue or list Number of Number of
  PNe miscl. PNe
Curtis (1918)   102    
Vorontsov-Velyaminov, Parenago (1931)   121    
Vorontsov-Velyaminov (1948)   288    
Vorontsov-Velyaminov (1962)   591    
Perek, Kohoutek (1967) - CGPN(1967) 1036    
Kohoutek (1978-2000) - Supplements 1-6 to CGPN(1967)   721   247
Acker et al. (1992) - SECGPN 1143 *) 330
    347 **)  
Acker et al. (1996) - Supplement 1 to SECGPN   242 *)  
    142 **)  
This catalogue - CGPN(2000) 1510   245

*)   true or probable
**)  possible




next up previous
Nächste Seite: Individual distances Aufwärts: Elementary Statistics Vorherige Seite: Coordinates and finding charts
Lubos Kohoutek
2001-04-02