Cosmic Burger

Credit: NASA, ESA, and The Hub­ble Her­itage Team (STScI/AURA)

Would you like fries with that giant cos­mic ham­burger? Gomez’s Ham­burger is a strange plan­e­tary neb­ula that looks like a ham­burger but it’s actu­ally a sun-like star near­ing the end of its life. The cen­tral star, which we can­not see in this image, expelled large amounts of gas and dust and may one day develop a more famil­iar col­or­ful, glow­ing plan­e­tary nebula.

We can play with our food here and you should explore the image. The buns are made up of light reflect­ing off dust clouds. A dark band of dust in the mid­dle makes up the ham­burger patty. Astronomers don’t quite know why this dark band has formed. It could be that the dark band, seen edge-on from Earth, is the shadow of a thick disk of dust being expelled from the equa­to­r­ial regions of the star as it spins rapidly.

Plan­e­tary neb­ula form when stars with masses sim­i­lar to our Sun reach the end of their lives. As fuel runs out to sus­tain nuclear fusion within the star’s core, it bal­loons in size to become a bloated red giant star. A red giant is hun­dreds of times big­ger around than the orig­i­nal star. Even­tu­ally, the star ejects its outer lay­ers into space leav­ing a hot core star called a white dwarf. As the bub­ble of gas and dust expands into space, ultra­vi­o­let radi­a­tion spilling from the cen­tral star causes the gas to glow.

We are see­ing Gomez’s Ham­burger in a spe­cial phase of its life. It hasn’t reached a true plan­e­tary neb­ula stage just yet. This period of its evo­lu­tion will last only a few thou­sand years. Soon the cen­tral star will become hot, blow­ing dust par­ti­cles out­ward and light­ing the inte­rior with ultra­vi­o­let light.

Gomez’s Ham­burger, located about 6,500 light-years from Earth toward the con­stel­la­tion Sagit­tar­ius, was dis­cov­ered on sky pho­tographs obtained by Arturo Gomez, an astronomer at the Cerro Tololo Inter-American Obser­va­tory in Chile.