The Additional Messier Objects

By /

The Additional Messier Objects

In addition to the 103 objects which were included in the final published

version of Charles Messier‘s

catalog,

he and his friend Pierre Mechain have

discovered others during the time when they compiled this listing, or shortly

(at most one year) later. More than a century later, astronomers have

decided to include these objects as additions in his list, with numbers

M104 thru M110.

M104 was discovered by Pierre Mechain on

May 11, 1781, and included by hand in Messier’s personal copy of his catalog

in the Connaissance des Temps for 1784. Camille Flammarion added it to

the Messier catalog in 1921. M104 is the only additional object which Burnham

accepts in his Celestial Handbook.

It is probably the decision of Camille Flammarion of 1921 to add M104 that

any of the additional objects were appended to Messier’s catalog.

M105,

M106, and

M107 were discovered by Pierre Mechain and

mentioned in his letter to Bernoulli, together with M104, in which he

disclaimed his M102 discovery (but see the

discussion of this subject). Mechain discovered

M105 on March 24, 1781, “near M95 and M96, … four or five days after the

other two.” M106 was found by him in July 1781, M107 in April 1782. Herewith,

globular cluster M107 was the last Messier object ever discovered.

M108 and

M109 were first seen by Pierre Mechain and

are mentioned in Messier’s original description of M97 in his final printed

version of the catalog. Apparently, Mechain saw these two object in the same

night as M97, on February 16, 1781, and Messier seems to have seen them also

on March 24, 1781 when he measured M97 and created the description –

according to the text of the description.

Nevertheless, Kenneth Glyn Jones states that M108 and M109 were discovered

“in 1781 or 1782”. These two objects were included into the catalog in 1953

by Owen Gingerich.

M110 was finally added by Kenneth Glyn Jones

in 1966. This one was discovered by Charles Messier on August 10, 1773, and

painted in his drawing of the Andromeda galaxy M31 (which also includes the

other companion galaxy, M32), published in 1807.

Since the first addition of M104, it is disputed if such a procedure makes

sense, as historically, Messier has only numbered 103 of the objects.

Burnham, e.g., only accepts M104 and disregards the others.

Besides the reasons given above for each object, the general argument holds

that they were known to Messier and Mechain.

Also, Messier’s list together with these objects summarizes most

deepsky objects north enough to view them from the latitude of Paris,

and known before Herschel’s survey.

Moreover, these objects are now wellknown by their “M” numbers, especially

among amateurs, so that it seems appropriate to accept these additions.

Scroll to Top