it is a quite stunning picture of "some" night sky
i really do not have any visual or technique critique to offer other then that you made the wrong part bright immanent that you look on the night sky.. would a bright nebula show allot of stars around it or would the sky around it show allot of stars.. if you think about it do you see allot of stars around the moon? even so i might have gotten the picture wrong and that it is not a nebula at all but maybe the center of the milky-way? and that the stars you see are infact a binary system of allot more then 2stars or even really close planets. other that that it is quite stunning in vision impact and technique and even thou the nebula was a quite boring colour it is still REALLY realistic to the colour you see when you look at our center and even thou it melds with the purple so well that it does not look "boring" but quite natural and mild to the eye in it's totality.
about the originality it is a night sky we all seen it way to many times but few menage to make it pleasant to the eye and least of all interesting to look at witch you did quite well.
one last thing.. the 2 comets on the right sight of the painting i do think it would look better with maybe only one of them and not quite as bright as they are now.