Butterfly Wings

Credit: Mas­simo Sti­avelli (STScI), and NASA

This butterfly-wing shaped neb­ula is larger than the solar sys­tem. NGC 2346 shows the last gasp of a binary star sys­tem. The two stars at the cen­ter of the neb­ula are so close that they orbit each other every 16 days. They are so close together that even the huge and pow­er­ful Hub­ble Space Tele­scope can­not tell them apart. Astronomers believe that one of the stars grew to become a red giant and actu­ally swal­lowed its part­ner. Then the two became even closer together before parts of the stars were thrown off into space. At first this star stuff made of gas and dust moved out in a bub­ble. But sci­en­tists think that one of the stars devel­oped a fast solar wind caus­ing the but­ter­fly wings to form.

NGC 2346 plan­e­tary neb­ula is about 2,000 light years away toward the con­stel­la­tion Mono­c­eros, the unicorn.