Messiercertificate
Visually
I got my Messiercertificate on 12.04.1991. Finally I had seen all Messierobjects and registered in the observation book (at that time still a computer endless form).
Here is the excerpt from the observation book, logging the last Messier object:
12.04.91, 21h00m, Schnaittach, 12.5 “, Seeing 7, Trans 3-4, fst. = 5.5m, hazy night with light pollution in the south and west, with Jürgen L., Dieter P., Manfred S., Site: Schnaittach
M83 NGC5236 Gx, Hya, 0h46m, 66x, last Messier object which was missing.
Photographically
On 27.08.2003 I finally had photographed all Messierobjects
Messier in Paris
The pictures below have been taken during a holiday in 2004 in Paris.
Messier’s observatory, the former observatory the navy (Hotel de Cluny) 
Me at Messier’s grave on the cemetery Pere-Lachaise 
Messier’s grave on the cemetery Pere-Lachaise 
Messier’s observatory, the former observatory the navy (Hotel de Cluny)
Messiermarathon
Messiermarathon Wettersberg 1993
At a certain time in the spring, it is possible to observe all Messier objects in one night. What is important is a unobstructed view and excellent observation conditions, especially on the horizon. On 19.03.1993 Klaus Veit, Ronald Stoyan and I tried a Messiermarathon. The observation conditions were very good in that night.
Observation excerpt:
19-20.03.93, 18h30m-6h00m, Wetterberg, 12.5 “, fstpol. = 6.3-6.5m, observers: Klaus Veit (98 objects) and Ronald Stoyan (103 objects), Thomas Jäger (101 objects)
Agreement:
M24 = Small Sagittarius Star Cloud
M40 = double star Winnecke4
M91 = NGC4548, M102 = NGC5866, M110 = NGC205
I left: M74, M54, M70, M69, M55, M75, M72, M73, M30
Messiermarathon Fränkische Schweiz
Original protocol part 1 
Original protocol part 2 
Original protocol part 3 
Me, my car, at dusk after the messier marathon 
10″ Newton
More than 18 years have passed since my first Messier marathon. On Saturday, 4.04.2011, Ronald Stoyan, Klaus Veit and I again did a Messiermarathon. Other observers were Stefan S. and Klaus T. Everyone participated in the Messier marathon.
Telescope: 10 “Dobson on equatorial platform
Location: Fränkische Schweiz
Not seen were: M74, M54, M70, M69, M55, M75, M72, M73, M73, M30
Messier Marathon Roadmap was created by Ronald Stoyan.