another strange offset (Halifax)

Received another BGO image set for the Rosette mosaic project.

This request had the offset=135,85 centred on the star HIP31130. After the weird hop on 21 Jan, I wasn't sure what to expect...

All full size. Luminance, HA, and O3 chosen. All 60 seconds by 10 exposures.

So, the 135 RA offset is working as expected. It aligns with the other 135 images.

The 85 Dec offset is still strange. Now it is consistent with the 21 Jan image run: it elevated the same amount as the 50,85 image. But I don't understand why the 85 makes it go so far. 

Again, this leaves a huge gap...

FITS Liberator. GIMP. That gradient must be from the Moon...

Tons of stars! Caught the open cluster NGC 2252 to the north-east... Funny backwards question mark. Oh well.

What is the reference? I thought it was the long edge for a bit. 

Actually, I think that is it!

OK. Now I can redo the plan.

I'll let the human know...