Moon. Best 60% of 68 images, 0.17 sec, OIII filter
Crop of Mare Imbrium
There are two distinctive craters in Mare Imbrium, Helicon and Le Verrier.
I had a look at the smaller craters Le Verrier A, B, C etc, to see the smallest ones I could detect.
Le Verrier X is 3km across
There is a 3.6 km crater just below Le Verrier which I can also just about make out.
(image from Wikipedia)
The Moon was 362133km away at the time of the image.
A 3km crater subtends an angle of 1.7 arc seconds at this distance.
The images are at 0.87arc seconds per pixel, so it looks like I will struggle to detect anything much smaller than Le Verrier X.
Quasar PS1 J161737.78+595020.1
This is now the most distant object I have imaged.
It has a redshift of 4.351 which puts it at 12.299 billion light years.
This is the time of light travel - universe expansion means the quasar is now at 24.572 billion light years distance from us.
Astrometry confirms the objects location:
Supernova in M85
I had retired for the night and then saw on Twitter that there was a reported supernova in galaxy M85.
The sky was cloudy, mostly thin high level stuff and I could only get two 600 second images.
The SN was visible, only just.
The magnitude was 17.0
It has since been classified as a type 1a supernova