NGC2440-a

NGC 2440

NGC 2440 is another planetary nebula ejected by a dying star, but it
has a much more chaotic structure than NGC 2346. The central star of
NGC 2440 is one of the hottest known, with a surface temperature near
200,000 degrees Celsius. The complex structure of the surrounding
nebula suggests to some astronomers that there have been periodic
oppositely directed outflows from the central star, somewhat similar
to that in NGC 2346, but in the case of NGC 2440 these outflows have
been episodic, and in different directions during each episode. The
nebula is also rich in clouds of dust, some of which form long, dark
streaks pointing away from the central star. In addition to the bright
nebula, which glows because of fluorescence due to ultraviolet
radiation from the hot star, NGC 2440 is surrounded by a much larger
cloud of cooler gas which is invisible in ordinary light but can be
detected with infrared telescopes. NGC 2440 lies about 4,000
light-years from Earth in the direction of the constellation Puppis.

The Hubble Heritage team made this image from observations of NGC 2440
acquired by Howard Bond (STScI) and Robin Ciardullo (Penn State).

Image Credit: NASA/The Hubble Heritage Team (AURA/STScI).