[avandonk]

The blue 'haze' around the bright stars could be due to a combination of scatter from the objective and or the LPS filter. Atmospheric scatter could also contribute. When stars are this bright even a tiny percentage of reflections from the bright source show up. Even multiple reflections can then be an artefact.

This is always a problem with bright objects and long exposures. This can be easily checked by offsetting the object and see if the artefact occurrs the same distance on the opposite side of the optics axis if due to the optic. If due to filters etc closer to the sensor the artefact will be offset slightly away from center from the object that causes it.

If it is atmospheric it will simply follow the object.

Is a sunset any less beautiful if you consider it is due to atmospheric Rayleigh scattering and therefore an artefact?

This is only a problem if you start to think it is real. Just google Baxendell's Unphotographable Nebula for a classic case of an artefact mistaken for a real object. Canals on Mars is another that comes to mind. These were both visual artefacts.

The old axiom of believe nothing of what you hear and only half of what you see serves as a good warning when looking for the "Truth".

Bert