ROAST ::

A few nights ago I took some more images of Markarian’s Chain, and while it wasn’t a great session (clouds), I did learn something about when to observe.

I took 210 photos with 30-second exposures, and the Mini rejected 14 of them — all due to satellites, mostly Starlinks I think.

Here’s a quick manual stack of the rejected frames:

They haven’t been demosaiced or aligned (hence the green tint); I just wanted to see the satellite tracks, all in a pretty small area of the sky.

What I learned was this: sessions should start as late as possible. I started imaging at 9:10pm, and finished at 23:12. All the failures happened before 22:22pm, by which time the sun had moved far enough below the horizon that the satellites weren’t illuminated any more — all those Starlinks are in low orbit.

Unfortunately, that means that in the summer (shorter nights) we’ll get many more trails. :-(