Catharina sunset crater ray

[Nyctimene]

Was out, unplanned once more, for a lunar observation this morning from 03.15 to 04.30 CET, with the 5.1" f/5 Skywatcher Heritage Flextube. Seeing was not the best, but improved to average during the session. I started with the rilles system Rimae Bürg, in Lacus Mortis, just under the terminator. Dorsa Smirnov and Lister were conspicuous. The faint structure of Lamont, that I had observed first this year in March, was more distinct this time, and I found Pbyrne's annotation to my post of  March 8th here ("looks like a spider, that has been stepped on") really striking. Rimae Hypatia, Ariadaeus and Hyginus were prominent, whereas Rimea Triesnecker were more difficult and only observable in seconds of good seeing. Catena Abulfeda showed it's craterlets of different size readily at 183x mag. Finally, I observed a crater ray phenomenon on the floor and eastern crater wall of Catharina. The spike/wedge of light extended on the crater's floor from the middle to the east, broadening, and rising up the inner crater wall - an unexpected and beautiful sight, not much behind the Hesiodus ray. Pleased, and so to bed. I was glad to be able to reconfirm my impression by looking the data up here (an excellent resource of crater ray phenomena; and spot on!):

http://www.lunar-occultations.com/rlo/rays/rays.htm

Always something new to spot on the moon!

Thanks for reading

Stephan

 

 

[cloudsweeper]

Nice read, Stephan - just what I need while it's wall-to-wall cloud here lately.  And Yes, the Moon always has something to please!

Doug.