by APOD Robot » Tue Oct 03, 2023 4:07 am
MyCn 18: The Engraved Hourglass Planetary Nebula
Explanation: Do you see the hourglass shape -- or does it see you? If you can picture it, the rings of
MyCn 18 trace the outline of an hourglass -- although one with an unusual eye in its center. Either way, 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 featured here. Pictured, 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 Hubble 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 like MyCn 18.
[url=https://apod.nasa.gov/apod/ap231003.html] [img]https://apod.nasa.gov/apod/calendar/S_231003.jpg[/img] [size=150]MyCn 18: The Engraved Hourglass Planetary Nebula[/size][/url]
[b] Explanation: [/b] Do you see the hourglass shape -- or does it see you? If you can picture it, the rings of [url=https://en.wikipedia.org/wiki/Engraved_Hourglass_Nebula]MyCn 18[/url] trace the outline of an hourglass -- although one with an unusual eye in its center. Either way, the sands of time are running out for the central star of this hourglass-shaped [url=https://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url]. With its [url=https://www.nasa.gov/directorates/spacetech/game_changing_development/Nuclear_Thermal_Propulsion_Deep_Space_Exploration]nuclear fuel[/url] exhausted, this brief, spectacular, closing phase of a [url=https://science.nasa.gov/sun/]Sun[/url]-like [url=http://apod.pl/htmltest/gifcity/msblues.html]star's life[/url] occurs as its outer layers are ejected - its core becoming a cooling, fading [url=https://apod.nasa.gov/apod/ap000910.html]white dwarf[/url]. In 1995, astronomers used the [url=https://apod.nasa.gov/apod/ap010806.html]Hubble Space Telescope[/url] (HST) to make a series of images of [url=https://esahubble.org/wordbank/planetary-nebula/]planetary nebulae[/url], including the one featured here. Pictured, delicate rings of colorful glowing gas ([url=https://periodic.lanl.gov/7.shtml]nitrogen[/url]-red, [url=http://www.youtube.com/watch?v=lFptgQ8GA_U]hydrogen[/url]-green, and [url=http://education.jlab.org/itselemental/ele008.html]oxygen[/url]-blue) outline the tenuous walls of the [url=https://en.wikipedia.org/wiki/Hourglass]hourglass[/url]. The unprecedented sharpness of the Hubble images has revealed [url=https://ui.adsabs.harvard.edu/abs/2018PASA...35...27M/abstract]surprising details[/url] of the [url=https://apod.nasa.gov/apod/ap200630.html]nebula ejection process[/url] that are helping to resolve the outstanding mysteries of the [url=http://faculty.washington.edu/balick/pPNe/]complex shapes and symmetries of planetary nebulas[/url] like MyCn 18.
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