MyCn18: An Hourglass Nebula
Explanation:
The sands of time are running out for the central star
of this hourglass-shaped
planetary nebula.
With its
nuclear fuel
exhausted, this brief, spectacular, closing phase of a
Sun-like
star's life
occurs as its outer layers are ejected - its core becoming a cooling, fading
White Dwarf.
Astronomers have recently used the
Hubble Space Telescope (HST)
to make a series of
images of
planetary nebulae, including
the one above.
Here, delicate rings of colorful glowing gas
(nitrogen-red, hydrogen-green, and oxygen-blue)
outline the tenuous walls of the "hourglass".
The unprecedented sharpness of the HST images has
revealed
surprising details
of the
nebula ejection process
and may help resolve the outstanding mystery
of the variety of complex
shapes and symmetries of planetary nebulae.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
