want to make night skies more black

Hello, last night I filmed the Aurora on my camera. I got some great footage, but the night skies have some artifacts that I would like to get rid of by making the blacks more black. I tried the colour grading presents and some of them are really good, but I loose some of the colours of the Aurora that I want to keep. I don't want to affect the native colours of the Aurora, I just want to affect the night sky behind it and bring out the stars that are within it out more and remove some of the red and blue artifacts but not loose the red within the Aurora itself.

Masking is out of the question because it moves so much, how can I use the Colour Board or whatever other colour adjustment setting to darken the skies. I want to make the blacks in like for example this screenshot of the top left to be more black and bring out the stars. Maybe bring out a bit more of the reds in the Aurora, but not at the expense of the black sky.

Can you help? Thank you!