Chris.B wrote:
Fist image shows tracking problems. All the stars show a clear but
minor 10 o'clock elongation.

Stars are round on the second and third images.Tightest on the second.
Focussing variations?

Your light track on the second image is resolved into 4 clearly
seperated round images if you enlarge the image. This suggests a
distant tumbling object with variable reflectivity I think. Or a
distant blinking object.

Chris.B

Edit: I meant to add that the trajectory of the object is not straight
but curves slightly upwards on the second image. The end of the track
is interesting. Seeming to curve steeply downwards and form a
fan-shaped spray of light towards the core. None of this appears on the
first or third images.

Do you have a larger second image we can look at to confirm this? :-)