Charles Messier
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Charles Messier (June 26, 1730 – April 12, 1817) was a French astronomer who in 1774 published a catalogue of 45 deep sky objects such as nebulae and star clusters. The purpose of the catalogue was to help comet hunters (like himself) and other astronomical observers to distinguish between permanent and transient objects in the sky.
Messier was born in Badonviller (in the Lorraine région of France), the 10th of 12 children of catchpole Nicolas Messier and Francoise b. Grandblaise. Six of his brothers and sisters died young, and in 1741, his father died. Charles' interest in astronomy was stimulated by the appearance of a great 6-tailed comet in 1744 and by an annular Solar eclipse visible from his hometown on July 25, 1748.
In 1751 he entered the employ of the astronomer of the Navy, Joseph Nicolas Delisle, who instructed him to keep careful records of his observations. Messier's first documented observation was that of the Mercury transit of May 6, 1753.
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[edit] His catalogue
The first version of Messier's catalogue contained 45 objects and was published in 1774 in the 1771 journal of the Academy of Sciences in Paris. By the time the final version of the catalogue was published in 1781, the catalogue had grown to 103 'Messier Objects'. On several different occasions between 1921 and 1966, astronomers and historians discovered evidence of another seven deep-sky objects that were observed by Messier and/or his friend and assistant Pierre Mechain shortly after the final version was published. These seven objects, M104 through M110, are accepted by many astronomers as "official" Messier objects. The objects' designations, from M1 to M110, are still in use by professional and amateur astronomers today.
The catalog is not scientifically organized by object type or by location (as the later New General Catalogue would be). Nonetheless, the Messier catalog comprises examples of every known deep sky object, including galaxies, planetary nebulae, open clusters, and globular clusters. Because these objects were accessible to the relatively small aperture telescope (approximately 102 mm, or 4 inches) used by Messier to study the sky, they are among the most spectacular deep sky objects available to modern amateur astronomers using much better equipment. Furthermore almost all of the Messier objects are among the closest to our planet in their respective classes, which makes them heavily studied with professional class instruments that today can resolve very small and visually spectacular details in them. Professional astronomers still refer to objects by their Messier designation, and in amateur astronomy they are among the most frequently visited deep sky objects. The "Messier Marathon," includes the Crab Nebula (M1) to a small elliptical galaxy near Andromeda (M110). In Messier marathons, many amateur astronomers compete to view all 110 of these objects in a single dusk-to-dawn session, usually in March, when conditions are most favorable. Many of the Messier objects can be seen in binoculars or small 50 mm telescopes used as finders on larger telescopes. A few Messiers are naked eye objects: examples include a globular cluster, M13 in Hercules, and more readily, M31, the Andromeda Galaxy, as well as M42, the Orion Nebula, and M45, also known as the Pleiades or Seven Sisters.
Many of the objects in the Messier catalog were discovered by his assistant Pierre Mechain.
Two objects in the Messier catalog are not deep-sky objects but rather small groupings of stars that appeared nebulous and fuzzy through Messier's optics. The object designated M73 is an asterism, a Y-shaped figure of four stars, while M40 is nothing more than a double star in Ursa Major.
Another object, M102, may be the 10th magnitude galaxy NGC 5866 in Draco. This is a disputed object; a considerable body of scholarship indicates that this is a bookkeeping error and a double entry for M101, which lies 9 degrees almost due west. A dissenting view is that Messier correctly identified the object. The major alternate designation, universally accepted, is NGC 5866. Whatever the merits of this debate, NGC 5866 is winning a low-key popular struggle to assume the identity of M102. This is not due to any academic resolution of the issues, but because makers of computer databases for modern amateur telescopes and sky software for personal computers don't like to have a blank space in their Messier list and typically prefer not to send users back to M101. Here the goal is to maximize viewing pleasure regardless of scholastic accuracy. It is true that NGC 5866 is bright enough to have been identified by Messier's equipment and like the other Messier objects is readily viewed in small aperture or "back yard" instruments.
Some of the Messier objects have been so frequently photographed and reproduced that they are part of the popular culture. For example, the closing credit sequence of the 1960s show "The Outer Limits," included spooky music and a photograph of M104, an edge on galaxy bisected by a dark lane of dust. M104 is nicknamed "the Sombrero Galaxy." The naked eye object M45 also serves as the corporate logo for the Subaru corporation in Japan.
The Messier crater on the Moon and the asteroid 7359 Messier were named in his honor.
[edit] See also
[edit] Sources
- O'Meara, Stephen James (1998). Deep Sky Companions: The Messier Objects. Cambridge University Press.
