Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

June 22, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

PKS285-02: A Young Planetary Nebula
Credit: R. Sahai & J. Trauger (JPL), WFPC2, HST, NASA

Explanation: How do planetary nebulae acquire their exquisite geometrical shapes? To investigate this, astronomers used the Hubble Space Telescope to image several young planetary nebulae. These nebulae are the outer envelopes of stars like our Sun that have recently been cast away to space, leaving behind a core fading to become a white dwarf. In this photograph in red H-alphacarbon that composes humans is thought to be created by red giant stars and ejected into the cosmos in planetary nebulae like PKS285-02. The complexity of this nebula leads some astronomers to hypothesize that these shells were created by high-speed, collimated outflows during a late phase of this star's evolution.

Tomorrow's picture: A Giant Neutrino Ball

< Archive | Index | Search | Calendar | Glossary | Education | About APOD >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.