Hubble watches cosmic 'butterfly' emerge

larger   Nebula CRL 618

(CNN) -- A newly released image from the Hubble Space Telescope reveals unprecedented detail within a rare astronomical "butterfly."

The intriguing proto-planetary nebula CRL 618 is changing so rapidly that astronomers have been able to make direct observations of its cosmic evolution over the past 20 years, according to the European Space Agency (ESA).

The Hubble's sharp vision reveals a previously unknown richness of detail, the ESA said.

CRL 618 is an example of the transition taking place in the later stages of the life of a star similar to the sun after it has lost most of its mass and before it emerges as a fully-fledged butterfly-like planetary nebula, astronomers said.

	INTERACTIVE
Cult 3D model of Hubble Space Telescope
	MESSAGE BOARD
Stargazing

The Hubble observations reveal complex jet-like features protruding at different angles from the poles -- telltale signs of massive outflows of material spewing out at incredible speeds, astronomers said. Outflow speeds of more than 700,000 km/h (434,000 mph) have been measured in earlier observations.

Proto-planetary nebulae represent the transition phase between the last stages of a red giant star's life and the later planetary nebula phase, where most of the star's mass has been ejected, astronomers said.

While proto-planetary nebulae are useful for testing theories of the origin and evolution of planetary nebulae, the CRL 618's enigmatic structure remains a puzzle to astronomers and challenges existing theories.

This Hubble image shows that as material is ejected it forms complex shapes and symmetries, rather than the spherical structure simple theories predict. The powerful processes that created those formations have yet to be explained.

The Hubble Space Telescope is a project of international co-operation between NASA and ESA.

Hubble shows mystery object in new light
August 31, 2000
Hubble images reveal details of comet's breakup
August 10, 2000
Hubble investigates mystery of a dying star
August 3, 2000
Comet erupts violently as Hubble watches
July 28, 2000

Space Telescope Science Institute
Spacelink - Hubble Space Telescope
NASA K-12 Internet: Live from the Hubble Space Telescope
NASA
European Space Agency

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.