Craters north of Grimaldi

[Nyctimene]

This morning, I took out the 80/400 grab-and-go frac for an unplanned moon session. The terminator was near Grimaldi, and I could make out a crater chain extending north of Grimaldi. The smallest one was Lohrmann, directly adjacent Hevelius, followed by Cavalerius, all of them perspectively distorted ovals due to the location near the lunar limb. The central mountains could be seen despite  the rather bad seeing. Further north, the sunlit rims of the craters Cardanus, Krafft, and Eddington just began to show up. Seleucus and Reiner were distinct features, as was the albedo phenomenon Reiner Gamma.

Observing Lohrmann brought back memories from 1977, when I bought a copy of his lunar atlas ("Mondkarte"), published (long after his early death with 44) 1874. Surveyor by profession, he based the drawings of his 25-sections map of nearly 1 m diameter on 79 precise positions, measured with a 122/1950 mm Fraunhofer refractor. Here's a picture to show the enthusiasm of this almost forgotten professional amateur. The crater bearing his name is just at the moon equator between Grimaldi (left) and Hevelius (right).

Stephan

[Paz]

A very nice map. I will look out for those craters neat Grimaldi. I've just come in from a shirt stint that included checking out the moon. Grimaldi (and Plato) stood out as  the darkest features for some reason.

[SilverAstro]

On 10/04/2017 at 16:57, Nyctimene said:

Observing Lohrmann brought back memories from 1977, when I bought a copy of his lunar atlas

Thanks for the interesting info., he is now on my agenda for the next lunation 

 

[Nyctimene]

Paz and Silver Astro,

thanks for your replies and likes; nice to see your interest in Lohrmann, who was characterized in the short biography by Joseph Ashbrook ("Astronomical scrapbook", Ch. 49) as "the first true mapper of the Moon". Paul Ahnert, Sonneberg Observatory, editor of the "Mondkarte", second edition 1963, measured some of Lohrmanns positions again  for their accuracy, and found values of –/+ 0,7mm max. deviation referring to the scale of the map - and Lohrmann's refractor had no clock drive, just manual slow motions!

There is access to the whole map of Lohrmann/Schmidt, have a look:

https://www.der-mond.org/mondkarte/historische-mondkarte-von-julius-schmidt/

You can even download  hi-res pictures.

Ahnert comments on Lohrmanns portrait: "To me he has always seemed a particularly sympathetic and attractive personality, and I believe,his portrait bears this out".

I'm glad, he now has found some worthy place here in this friendly and sympathetic forum.

 

Stephan

 

 

[johnfosteruk]

Great report Stephan, and what a wonderful map. I'll be paying him a visit next lunation and you have me browsing the internets hunting down "Mondkarte" to decorate the study wall!