Garden Spider

Credit: NASA, ESA, and K. Noll (STScI)

In the starry gar­dens of the con­stel­la­tion of Pup­pis, you’ll find this but­ter­fly or spider-looking neb­ula. NGC 2440 is a plan­e­tary neb­ula and is the remains of a star like our Sun. The cen­tral star cast off its outer lay­ers as it came to the point where it could no longer keep up nuclear fusion in its core. Nuclear fusion is what pow­ers a star, giv­ing out light, heat and other radi­a­tion. Ultra­vi­o­let light from the burned-out star, called a white dwarf, causes the gas around the star to glow. Find the white dot in the cen­ter of the nebula.

This dying star cre­ated a cocoon of gas and dust around itself. Even­tu­ally our Sun will burn out and cre­ate a neb­ula like this one; but not for another 5 bil­lion years. Some plan­e­tary neb­ula have uni­form rings around the star. NASA’s Hub­ble Space Tele­scope shows in this image that NGC 2440 is more jum­bled sug­gest­ing that it shed lay­ers in cycles. Each out­burst sent mate­r­ial in a dif­fer­ent direc­tion. Can you find the dusty lanes in the cloud point­ing back to the star?

Plan­e­tary neb­ula have noth­ing to do with plan­ets. In the 18th and 19th cen­tury, astronomers came across neb­ula that resem­bled the disks of dis­tant plan­ets. At that time, astronomers didn’t know that the neb­ula were the remains of dead or dying stars. Even­tu­ally, astronomers found that the Milky Way is lit­tered with these starry remains.

NGC 2440 lies about 4,000 light-years away toward the con­stel­la­tion Pup­pis. Pup­pis is a con­stel­la­tion in the south­ern sky and is Latin for the poop deck of a ship. The con­stel­la­tion was orig­i­nally part of the larger con­stel­la­tion Argo Navis, named after the ship of the myth­i­cal Jason and the Argonauts.