From 1758 to 1782 Charles Messier, a comet-hunting French astronomer (1730 - 1817), sought
to catalog the location of deepsky objects that could easily be mistaken for
comets in small telescopes.
His list
contains a few more than 100 diffuse objects.
The actual number is controversial because of problems with identifying certain
objects. M40 may not exist at all, or at best is a dim double star pair. M102 is probably a duplicate
entry of M101.
Today the list is considered the sky's very best showpiece objects for deepsky
enthusiasts. All the objects can be seen with small amateur telescopes and many can be
seen with binoculars.
Click the thumbnails for larger displays of the images.