Variable star and disk. Image 2 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 an active phase and material from the disk is falling onto the star, causing an increase in brightness and a loss of material from the disk. The surrounding nebula (a few light years across, not shown) was discovered because of this increase in brightness, shown in images R670/184-187. The star is about 1500 light years from Earth in the constellation of Orion.