De Cheseaux's List of 21 "Nebulae" -

De Cheseaux’s List of 21 “Nebulae”

The Swiss astronomer and mathematician Philippe Loys de Cheseaux (1718-51)

became known because of his discovery and observations of the famous comet of

December 1743 to March 1744, which became very brilliant, exposed six tails,

and also impressed 13-year-old Charles Messier in his Lorrainian hometown.

About in 1746, he also observed several clusters and “nebulous stars”, and

compiled a catalog of their positions.

According to Kenneth Glyn Jones, 8 of them were original discoveries:

IC 4665 (No. 2, maybe doubty),

NGC 6633 (No. 3),

M16 (No. 4),

M25 (No. 5),

M35 (No. 12, but this one might have seen before

by John Bevis in England),

M71 (No. 13),

M4 (No. 19), and

M17 (No. 20).

Moreover, he independently re-discovered

M6 (No. 1),

NGC 6231 (No. 9, together with stars z1

and z2 Scorpii)

and M22 (No. 17).

De Cheseaux’s list was given to Reaumur, who presented it to the French Academy

of Sciences on August 6, 1746, but it was not otherwise published.

It was investigated by Bigoudan in 1884 and became more wellknown only then.

A list of identifications of De Cheseaux’s objects follows:


de Cheseaux    Messier/NGC/IC      Remarks



  No.  1       M 6                 (!)

  No.  2       IC 4665 ?            ! 

  No.  3       NGC 6633             !

  No.  4       M16                  !

  No.  5       M25                  !

  No.  6       NGC 869, h Per

  No.  7       NGC 884, Chi Per

  No.  8       M 8

  No.  9       NGC 6231+z1,z2 Sco  (!)

  No. 10       M 7

  No. 11       M44

  No. 12       M35                  !?

  No. 13       M71                  !

  No. 14       M11

  No. 15       M31

  No. 16       M42

  No. 17       M22                 (!)

  No. 18       NGC 5139, Omega Cen

  No. 19       M 4                  !

  No. 20       M17                  ! 

  No. 21      [M13] - not seen