Planetary nebula have one star at the center, but the twin jet nebula is characterized as a bipolar nebula because it has two stars which help give it the wings that have led to the nickname cosmic butterfly.
While the larger star is nearing death, its companion star has already crossed over to the other side becoming a small white dwarf, essentially the corpse of a star. The butterfly-like shape is likely caused by the motion between the two stars orbiting their common center of mass, according to NASA. The gas from the larger star forms the two lobes instead of taking on a spherical appearance.
The cosmic butterfly's wings are expected to continue to spread, according to NASA's measurements. It may look pretty, but this cosmic butterfly is vicious. The growing lobes are twin jets of gas streaming into space at more than 621,400 miles per hour.