Messier object
The Messier Catalog is a collection of 110 astronomical objects, mainly galaxies, star clusters and nebulae.
The objects of the catalog was compiled 1764-1782 by the French astronomer Charles Messier, after a first version of the catalog then in collaboration with his colleague Pierre Méchain. Most of the catalog objects were not previously been known.
The Messier catalog was and is of great practical importance. He was one of the starting points for the systematic study of galaxies, nebulae and star clusters, and assigned by him numbers remain the usual name of many important celestial objects.
Genesis
Charles Messier's research interest was the " comet hunting ." Until 1801 he had discovered the impressive number of 20 new comets. Looking for comets he came again and again to diffuse " spots" which, although looked like comets, unlike those but their position in the sky does not appreciably changed. This non-existent self-motion pointed out that there are objects far outside the solar system.
To avoid confusion and not to waste time in the further search for comets to these objects, Messier put in a catalog misty objects whose position and visible properties he listed. Catalog number 1, in today's speech " Messier 1" or M1, the Crab Nebula ( Crab Nebula, Crab Nebula) was in the constellation Taurus. The other objects were numbered in the order of their inclusion in the catalog. The Andromeda galaxy, a galaxy in the constellation Andromeda, for example, carries the designation M31.
The actual catalog ultimately contained the objects M1 - M103 and was published in three parts:
Today, the Messier catalog comprises additionally the objects M104 to M110. M104 was registered by Messier in his own handwritten copy of his catalog. The objects M105 to M109 were discovered by Méchain 1781 and 1782 and found in a letter to Johann Bernoulli mention. M108 and M109 Messier himself mentioned in his description of the object M97, but took them for unknown reasons not as independent objects in his catalog. All these objects were only later, 1921-1966, attributed by historians of science the Messier catalog, most likely found on the grounds that they had input into the planned, but never published fourth version of Messier's catalog.
The last ever published by Messier Objects In particular, but also some properties of the published catalog were later discovered by different astronomers (about William Herschel ) regardless of Messier's observations again.
Importance
The Messier catalog was not the first catalog of this kind, but the first such catalog, which was sufficiently complete and accurate to be used for practical observations. Even today, most of the objects in the catalog are mainly known among their Messier numbers.
At the time of the Messier catalog, the nature of the objects recorded there was unclear. The researches that were clarifying what it had with galaxies, nebulae and star clusters to be attended by the Messier catalog, the New General Catalogue and Index Catalogue of their output.
Among amateur astronomers and public observatories in the Messier Catalog is especially popular because the objects listed therein can be observed with relatively small telescopes or strong binoculars already. A special observation task in this case represent so-called Messier Marathon, during which each participant must observe in the course of a single night all Messier objects.
Errors and limitations
The catalog has at most one faulty entry: prevails among historians of science is no agreement, whether it is in Messier 102 at an incorrect second performance of the object Messier 101 or to an observation of the "Spindle Galaxy " NGC 5866, which acts as the M102 in modern versions of the catalog.
Furthermore, the Messier catalog has two entries that do not denote a planar objects, namely, Messier 40, actually the double star Winnecke 4, and Messier 73, a group of stars that is not secured for whether they belong together as an open star clusters.
A number of well-known today mist not be found in the Messier catalog, because they are too faint. These include the Horsehead Nebula and some brighter galaxies that later in the New General Catalogue (1888 ) and the Index Catalogue ( first version 1895, second version 1908) were performed. Also, some brighter objects like the double cluster h Chi in Perseus and the Hyades have no catalog entry.
Generally only the visible from the northern hemisphere of objects were considered in the Messier catalog; more precisely, it contains no objects south of declination -35 degrees.
List of Messier objects
Table of abbreviations in the object type column
Overview map
The following star map shows the location of the 110 Messier objects in the sky