|
The Messier objects are a set of over 100 astronomical objects first listed by French astronomer Charles Messier in 1771.〔 〕 Messier was a comet hunter, and was frustrated by objects which resembled but were not comets, so he compiled a list of them,〔 〕 in collaboration with his assistant Pierre Méchain, to avoid wasting time on them. The number of objects in the catalog reached 103 during his lifetime but a few more thought to have been observed by Messier have been added by other astronomers over the years. A similar list had been published in 1654 by Giovanni Hodierna, but had no impact and was probably not known to Messier.〔Birthday of a star cluster, ''Astronomy Now'', January 2011, page 20.〕 ==Lists and editions== The first edition covered 45 objects numbered M1 to M45. The total list published by Messier finally contained 103 objects, but the list "got an independent life" by successive additions by other astronomers, motivating the additions by side notes in Messier’s and Mechain’s texts indicating that either of them knew of the objects. The first such addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding Messier’s side note in his 1781 edition exemplar of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967.〔 〕 M102 was observed by Méchain, who communicated his notes to Messier. Later, it was admitted by Méchain himself that this object does not exist, and it was simply a re-observation of M101. Some sources mention the galaxy NGC 5866 as an identification for M102. Messier's final catalogue was included in the ''Connaissance des Temps for 1784'' (published in 1781).〔 〕〔 〕 These objects are still known by their "Messier number" from this list. Messier lived and did his astronomical work at the Hôtel de Cluny (now the Musée national du Moyen Âge), in France. The list he compiled contains only objects found in the sky area he could observe: from the north celestial pole to a celestial latitude of about −35.7°. Objects visible only from the southern hemisphere, such as the Large and Small Magellanic Clouds, were not observed nor listed. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Messier object」の詳細全文を読む スポンサード リンク
|