In a blogpost from 2017 on this website, there is a photo of the Orion Nebula (taken with 8" telescope and captured on DSLR). The brightest stars in this image have trails of light shooting out, 4 of them, at right angles. I don't know what these are called so I'm calling them "artifacts." (But what is the name for this?). What causes this? Is it considered a negative or a desired effect? Is it controllable? In some photos they appear and in others, they do not (e.g., there is another image later in that same blog post where some stars are really big and bright but this effect is not present). I think they enhance the image, give it a sort of grandeur and impact. But in reality, this is not what the star looks like, it's a single point of light. So... how do you feel about this when it appears in an image, is it desirable and is it controllable?