Rotten Eggs

Credit: ESA & Valentin Bujarra­bal (Obser­va­to­rio Astro­nom­ico Nacional, Spain)

Stars like our Sun will die one day when they have used up all of their hydro­gen and helium fuel for nuclear fusion. For our Sun, that day is four bil­lion years in the future but all around the galaxy, astronomers find other stars mov­ing through that stage of star life. The Rot­ten Egg Neb­ula, shown in this NASA/ESA Hub­ble Space Tele­scope image, is a plan­e­tary neb­ula in the making.

Plan­e­tary neb­ula form when stars run out of gas and they can­not keep up nuclear fusion in their cores. Fusion is the power source of stars includ­ing our Sun. When this hap­pens, the dying stars blow off their outer lay­ers, cre­at­ing an expand­ing bub­ble of gas and dust. In the case of the Rot­ten Egg Neb­ula, this process is just start­ing with most of the mate­r­ial trav­el­ing in oppo­site direc­tions. The cen­tral star is hid­den but most of its mass has been blown away and is trav­el­ing in the yellow-colored gas and dust bub­ble. The yel­low gas is blow­ing very fast, more than one and a half mil­lion kilo­me­ters per sec­ond. Most of the star’s mass is con­tained in the yellow-colored gas and dust bubble.

Look for the blue wave at the left of the cen­tral star. The blue light is caused by the glow of hydro­gen and nitro­gen atoms as they slam into the slow mov­ing mate­r­ial that sur­rounds the star. This image shows for the first time these struc­tures pre­dicted by scientists.

The Rot­ten Egg Neb­ula is named because it con­tains a large amount of sul­fur com­pounds. It would be a very smelly neb­ula if one could smell in space. It is bet­ter known as the Cal­abash Neb­ula because of its odd shape. The neb­ula is about 1.4 light-years long. It is located in an open star clus­ter about 5,000 light-years away from Earth toward the con­stel­la­tion Pup­pis.