Complex sentence: Long and very long exposures taken at night can be combined to create timelapse animations, star trails, or using astrophotography processing techniques to create images of objects in the night sky like nebulae and galaxies.
Split into simpler sentences: Long and very long exposures taken at night can be combined to create time-lapse animations, including star trails. Astrophotographers can use processing techniques with such exposures to create images of deep-sky objects in the night sky, like nebulae and galaxies.