Koehler's Deepsky Catalog

Johann Gottfried Koehler's Deepsky Catalog

On December 17, 1778, Johann Gottfried Koehler communicated to Bode a list of 20 nebulous objects, which was published in the "Astronomisches Jahrbuch" for 1782 (Koehler and Bode, 1779). The original list contains one original discovery (of M67), the article in the Jahrbuch two further apparently original findings, of M59 and M60, as well as three other, presumably original discoveries. As Koehler gives no further detail, identification is tentative: Kenneth Glyn Jones (1969) finds they cannot be identified because "there are far to many bright nebulae near the northern wing of Virgo," but Wolfgang Steinicke proposes that these may be M84, M86, and M87, as they are the 3 most prominent "nebulae" in that region of the Virgo Cluster. All three proposed objects have been independently discovered two years later (March 18, 1781) by Charles Messier, alternatively their original discoverer.
In addition, an apparent independent finding by Koehler of M3 was announced in the "Jahrbuch" for 1785 (Koehler and Bode, 1782).

We also have the original Koehler catalog online.

No.     ID

 1      M22
 2      M28
 3      M8
 4      M10
 5      M12
 6      M27
 7      M71
 8A     M81
 8B     M82
 9      Asterism? (Sigma1, Sigma2 and Rho UMa)
10      M36
11      M38
12      Asterism (63, 64, 65 and 66 And)
13      M5
14      M2
15      M15
16      ?
17A     ? M51?
17B     ? M51B?
18      M13 (?)
19  !   M67
20      M11 (?)

    !   M59
    !   M60
    !?  M84
    !?  M86
    !?  M87

        M3   (addition of June 17, 1782)

The descriptions and drawings of Koehler's numbers 9, 12, and 16 are too inacurate for a safe identifiation of these objects; most of the drawings are completely useless for this purpose. Kenneth Glyn Jones (1969) identified No. 9 and 12 as probable asterisms, states that No. 16 is too unsafe for identification (the position is near the star 3 Vul in the Milky Way). Also according to Glyn Jones, No. 17 (17A and 17B) is left unclear, but he gives the speculation that this might be M51, a speculation that is augmented by the statement that it is a "double nebula"; if so, would include both M51(A) and M51B - in this case, it may well be that Koehler was the original discoverer of M51B = NGC 5195.

In addition to the objects listed, Bode announces that on May 5, 1779, Koehler had found "three other somewhat nebulous stars in the area of the northern shoulder of Virgo, at quite a distance of each other;" i.e., in the region of the Virgo Cluster. However, these are not specified to any detail, and therefore cannot be identified.

References

Johann Gottfried Koehler and Johann Elert Bode, 1779. Beobachtung des Kometen vom Jahr 1779 und Entdeckung einiger neuer Nebelsterne, vom Hrn. Inspector Koehler, vom Hr. Bode mitgetheilt [Observation of the comet of the year 1779 and discovery of some new nebulous stars, by Mr. Inspector Koehler, communicated by Mr. Bode]. Astronomisches Jahrbuch oder Ephemeriden für das Jahr 1782. nebst einer Sammlung der neuesten in die astronomischen Wissenschaften einschlagenden Beobachtungen, Nachrichten, Bemerkungen und Abhandlungen [Astronomical Yearbook or Ephemerides for the Year 1782, besides a collection of the newest observations, news, remarks and treatises impacting into the astronomical sciences]. Berlin, 1779, pp. 151-157 [Bibcode: 1779AJBer1782..151K] (here: pp. 155-7). Available online at MDZ -- Koehler catalog at MDZ. Translation of the Koehler catalog available online.
The corresponding figure with Koehler's drawings is printed in the consequent volume of Astronomisches Jahrbuch, Table 1: "Zum Astron. Jahrbuch 1782. IIte Abth. Seite 155 und 156 gehörig." Astronomisches Jahrbuch oder Ephemeriden für das Jahr 1783.., Berlin, 1780, p. 213, Tab. 1 [Bibcode: 1780AJBer1783..213.] Available online. Available online at MDZ.
Johann Gottfried Koehler and Johann Elert Bode, 1782. Beobachtung eines Nebelflecks beym Bootes, von Herrn Inspector Köhler. Aus einem Schreiben desselben vom 17. Jun. 1782 [Observation of a nebulous patch at Bootes, by Mr. Inspector Koehler. From a letter of the same of Jun. 17, 1782]. Astronomisches Jahrbuch oder Ephemeriden für das Jahr 1785. nebst einer Sammlung der neuesten in die astronomischen Wissenschaften einschlagenden Abhandlungen, Beobachtungen und Nachrichten. Berlin, 1782, pp. 230-231 [Bibcode: 1782AJBer1785..230K]. Translation available online. Available online at MDZ
Kenneth Glyn Jones, 1969. The Search for the Nebulae -- VI. Journal of the British Astronomical Association, Vol. 79, No. 3 (1969), pp. 213-222. Here pp. 219-222. [ADS: 1969JBAA...79..213J]. Reprinted in: The Search for the Nebulae. Chalfont St. Giles, 1975 [ADS: 1975sene.book.....J].

More Deepsky Observing lists

History of the Discovery of the Deepsky Objects

Some other historical catalogs

Hartmut Frommert
Christine Kronberg
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Last Modification: July 7, 2026
Former Definitive Version: September 12, 2006