Variable star and disk. Image 1 of 4. Artwork of the young star at the tip of McNeil's Nebula. Surrounding the star is a protoplanetary disk. McNeil's Nebula is a variable nebula that was discovered in January 2004. It is variable because the young star at its tip varies in brightness. Here, the star is in a quiet phase and it is not interacting with the surrounding disk of material. The surrounding nebula (a few light years across, not shown) was discovered when this star increased in brightness, probably due to material from the disk impacting the star. This is shown in images R670/184-187. This star is about 1500 light years from Earth in the constellation of Orion.