Painted Saturn

Credit: ESA/Hub­ble & NASA

Look­ing like a painted Sat­urn, NGC 6886 looks more like a planet than a star at then end of its life.

Explore a tiny plan­e­tary neb­ula in this NASA/ESA Hub­ble Space Tele­scope image. What sto­ries do you see in this image? Also explore Hub­ble images of the week at the Euro­pean Space Agency’s web­site.

Star death for mid-sized stars like our Sun is a long process. Hub­ble cap­tured this dying star just at the begin­ning of the end of its life. The star that cre­ated NGC 6886 is thought to have been sim­i­lar to our Sun. After liv­ing for more than eight bil­lion years, stars of this size burn up their sup­ply of hydro­gen fuel. The star bal­loons to great size and becomes a red giant. Any inner plan­ets that may have accom­pa­nied the star are incin­er­ated. Over time, the outer lay­ers of this star expand and cool cre­at­ing an expand­ing bub­ble of gas and dust around the star. Even­tu­ally, only the white-hot core of the star is left. This white dwarf will slowly cool over bil­lions of years. In the mean­time, the star unleashes a tor­rent of ultra­vi­o­let radi­a­tion that makes the bub­ble glow. A plan­e­tary neb­ula is born. Our Sun will likely form a plan­e­tary neb­ula in another four bil­lion years or so.

Plan­e­tary neb­u­lae have noth­ing to do with plan­ets. Astronomers in the 17th and 18th cen­turies, in their quest to find more plan­ets, found objects that through their tele­scopes resem­bled the plan­ets Uranus and Nep­tune. It wasn’t until the late 19th cen­tury that astronomers dis­cov­ered their true nature as dying stars.

NGC 6886 is found about 23,000 light years from Earth toward the small con­stel­la­tion Sagitta, the arrow. Sagitta is one of the orig­i­nal 48 con­stel­la­tions charted by Ptolemy dur­ing the sec­ond cen­tury AD.