zorg.ch
16:14 Uhr
Events
Forum
Games
Wetten
Rezepte
Tauschbörse
Books
Space
User
Übersicht
Astronomy Picture of the Day
MyCn18: An Hourglass Planetary Nebula
Bild Note: 4
(1 Vote)
⏴ previous
Bild Upload von 18.02.2016 21:43
next ⏵
zorg.ch
#113295
by
[z]Barbara Harris
@
08.08.2011 00:00
- nach oben -
MyCn18: An Hourglass Planetary 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
. In 1995, astronomers 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
that are
helping to resolve
the outstanding mysteries of the
complex shapes and symmetries of planetary nebulas
.
Credit & Copyright