The Red Rectangle Nebula, as its name implies, appears rectangular in shape and has a striking color along with an enormous X shape. And there is a star in the middle much like our Sun—or as it will be some 5 billion years in the future.
Because the star in question, named HD 44179, is in the process of dying, it is emitting gas and other material to form the spectacular nebula.
This is the sharpest image of it so far, and it shows the Red Rectangle actually forming an “X” shape, with lines connecting the arms like ladders. Similar images have been seen throughout the Milky Way and other galaxies for 30 years, but only now can we better understand it.
According to NASA, “the Red Rectangle is an unusual example of what is known as a proto-planetary nebula. These are old stars, on their way to becoming planetary nebulae. Once the expulsion of mass is complete a very hot white dwarf star will remain and its brilliant ultraviolet radiation will cause the surrounding gas to glow.”