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Hubble's view of planetary nebula NGC 2440

Our Milky Way Galaxy is littered with these stellar relics, called planetary nebulae even if the objects have nothing to do with planets. Eighteenth- and nineteenth-century astronomers called them in this way because - when watching them through small telescopes - they resembled the disks of the distant planets Uranus and Neptune.  
 

	NGC 2440 region

The planetary nebula in this image is called NGC 2440. The white dwarf at the centre of NGC 2440 is one of the hottest known, with a surface temperature of more than 200 000 degrees Celsius. The nebula's chaotic structure suggests that the star shed its mass episodically.

During each outburst, the star expelled material in a different direction. This can be seen in the two bowtie-shaped lobes. The nebula also is rich in clouds of dust, some of which form long, dark streaks pointing away from the star. NGC 2440 lies about 4 000 light-years from Earth in the direction of the constellation Puppis.
 
 

Zooming on NGC 2440

The material expelled by the star glows with different colours depending on its composition, its density and how close it is to the hot central star. Blue samples helium; blue-green oxygen, and red nitrogen and hydrogen. The image was taken on 6 February 2007 with Hubble’s Wide Field Planetary Camera 2.
 
 

	Panning on NGC 2440

Notes for editors
 
The Hubble Space Telescope is a project of international cooperation between NASA and ESA.
 
 
For more information
 
Lars Lindberg Christensen, Hubble/ESA, Garching, Germany
Email: lars @ eso.org

Keith Noll, Space Telescope Science Institute, Baltimore, USA
Email: noll @ stsci.edu

Ray Villard, Space Telescope Science Institute, Baltimore, USA
Email: villard @ stsci.edu