I bought a 'nebula filter' at some great cost and the attached was the result of four, two minute exposures on a recent clear night. I'm clearly struggling with getting the optimal exposure and Iso gain setting on my DSLR but the Orion Nebula came out fairly convincingly. There's plenty of detail in the main nebula that I don't see on the straight snapshot with similar (obvs lower) exposures so I 'believe the picture. So what is going on around the star down and to the right (Hatsia?)? There's a definite disc around it which is not present on other stars of equal apparent magnitude. Looking at similar images I have of the Pleiades, I can see the same effect on some stars but not on others. What's the opinion as to what the image is showing?