...so. that moment i find this, and my first thought is.. "could it be that aurora borealis was made by by main pony OC?"..its, kinda said OC's talent/ability, after all. they just, form behind her at night if she flies high enough. not a clue why it happens. but then, does everything need an explanation?
This is a very beautiful picture that you have made. I really love the aurora lights that you made they are very beautiful indeed. I also love the little village or small area of Ponyville that is in the distance, it helps set a certain mood to the overall picture. Luna looks very pretty in this picture, I think that you made her cutie mark perfectly, I love how it glows, like an actual moon would. I would say more, but it would take a long time, so I will end saying that overall this picture is a very beautiful picture that has a lot going for it, keep up the incredible work!!
Interesting that those are her sister's mane colors/energy... it has been proposed that Celly's mane changed from pink to aurora when she took over the night, because the aurorae are only visible at night, but are created by ?alpha particles? from the sun hitting the atmosphere.
Or is it the output from the Crystal Palace/Heart?
I don't think I can describe this with words, but really... The way you drew her garb and CM and the beautiful constellations in her mane, to the beautiful sky and the cozy village lights, you really did an amazing job!