What is the Messier List and Who was Messier?

What is the Messier List and Who was Messier?

Messier poster SEDS.jpg

Messier poster by Hartmut Frommert at SEDS

What is the Messier List?

The Messier List is a compilation of 110 deep space objects. This list is very popular with amateur astronomers that are starting out observing deep space objects. It is considered to be the first list of objects that backyard astronomers should attempt to view. 


What telescope do I need to see the objects?

Charles Messier observed all the objects with a telescope less powerful than a modern 60mm (2.4 inches) aperture refractor telescope but he had the benefit of very dark skies. Today the Messier list is considered to be observable with a 4 inch (100mm) telescope. A telescope of this size will allow you to see the objects but many will lack details and appear more like fuzzy patches. A good pair of 10x50 binoculars will allow you to see many of the objects on the list.


What types of objects can I see?

The Messier list was compiled to prevent Charles Messier from mistaking comets, which change position in the sky, with deep space objects, that remain fixed in position in the sky. Messier was a comet hunter, so the deep space objects that he listed, and was trying to avoid mistaking for comets, tended to appear like comets in his telescope. For this reason the list contains mostly small, fuzzy and quite dim objects. These include nebulae, planetary nebulae, globular star clusters, open star clusters and galaxies.

There are however a few anomlies in the list. For example, the Orion nebula and the Pleiades are included. These can't really ever be mistaken for comets. Messier included these, M43 and the equally un-comet like Praesepe star cluster all on the same night. Maybe it was a lapse or maybe it was to bring the list to 45 objects and therefore, exceed the 42 listed objects in Lacaille's list of 1755.

The list also contains some other unusual objects like the Milky Way star cloud (M24) and a double star (M40).


Who was Messier?

Charles Messier.jpg

Charles Messier was a comet hunter and astronomer born 26 June 1730 and died 12 April 1817. He lived in Paris and created his list using a small telescope by todays standards from under the beautifully dark skies of Paris. A feat that would not be possible with todays light pollution.

Messier lost his Father when he was 11 years old and 6 of his 11 siblings. Shortly after his father's death he observed the great six-tailed comet in 1744 and then an annular solar eclipse in 1748. Three years later he was working for an astronomer.

The first edition of the Messier list was published in 1774 and contained 45 non-comet objects and the final version was published in 1781 containing 103 objects. So why are there 110 objects today? 

In 1966 the list gained another 7 objects to make the modern total of 110. This was because historians discovered that Messier and his assistant Mechain had discovered more objects that didn't make it into the final publication.

Charles Messier eventually discovered 13 comets in his career.


Now try going on to the Caldwell List

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