Portal:Astronomy/Picture/Week 47 2006

NGC 2346 is an unusually shaped planetary nebula. The cause of its shape is the binary system at its centre: when one of the two stars evolved into a red giant, it engulfed its companion, which stripped away a ring of material from the larger star’s atmosphere. When the red giant’s core was exposed, a fast stellar wind inflated two ‘bubbles’ from either side of the ring.