APOD: Halo of the Cat's Eye (2020 Jun 07)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 5604
Joined: Fri Dec 04, 2009 3:27 am

APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by APOD Robot » Sun Jun 07, 2020 4:05 am

Image Halo of the Cat's Eye

Explanation: The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula. Made with data from the Nordic Optical Telescope in the Canary Islands, the composite picture shows extended emission from the nebula. Planetary nebulae have long been appreciated as a final phase in the life of a Sun-like star. Only much more recently however, have some planetaries been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50,000 to 90,000 years.

<< Previous APOD This Day in APOD Next APOD >>

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by orin stepanek » Sun Jun 07, 2020 10:44 am

catseye2_not_960.jpg
Reminds me of a beautiful flower, burst into bloom! :D
You do not have the required permissions to view the files attached to this post.
Orin

Smile today; tomorrow's another day!

User avatar
Ann
4725 Å
Posts: 13867
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by Ann » Sun Jun 07, 2020 2:18 pm

Color Commentator

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by neufer » Sun Jun 07, 2020 4:10 pm

APOD Robot wrote: Sun Jun 07, 2020 4:05 am
The Cat's Eye Nebula (NGC 6543)'s haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula.

This [NOT in the Canary Islands] composite picture shows extended emission from the nebula.
Art Neuendorffer

Sa Ji Tario

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by Sa Ji Tario » Sun Jun 07, 2020 4:48 pm

¿Can anyone explain what the spokes are like Japanese parasol rods seen in some images?

User avatar
Ann
4725 Å
Posts: 13867
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by Ann » Sun Jun 07, 2020 5:14 pm

neufer wrote: Sun Jun 07, 2020 4:10 pm
APOD Robot wrote: Sun Jun 07, 2020 4:05 am
The Cat's Eye Nebula (NGC 6543)'s haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula.

This [NOT in the Canary Islands] composite picture shows extended emission from the nebula.


Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Could frame thy fearful symmetry?

Ann
Color Commentator

ecdowney
Asternaut
Posts: 5
Joined: Mon Mar 12, 2007 4:54 am

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by ecdowney » Sun Jun 07, 2020 5:17 pm

If radius is proportional to time back, it looks like at first there was no rotation (outer third), then equal emission in all directions (middle third), and now leisurely rotation (inner third). Is this a correct interpretation? If so, what caused the change in rotation, perhaps asymmetric emission?

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by orin stepanek » Sun Jun 07, 2020 6:08 pm

neufer wrote: Sun Jun 07, 2020 4:10 pm
APOD Robot wrote: Sun Jun 07, 2020 4:05 am
The Cat's Eye Nebula (NGC 6543)'s haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula.

This [NOT in the Canary Islands] composite picture shows extended emission from the nebula.


I thaut I saw a putty-cat! I don't think that's Sylvester though! :shock:
Sylvester & Tweety today
>
th.jpg
Picture from image results
You do not have the required permissions to view the files attached to this post.
Orin

Smile today; tomorrow's another day!

ta152h0
Schooled
Posts: 1399
Joined: Mon Aug 29, 2005 12:46 am
Location: Auburn, Washington, USA

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by ta152h0 » Mon Jun 08, 2020 2:20 am

Earth is a product of accretion of particles over a long time. What makes the center of the Earth a fireball? pass the ice cold one
Wolf Kotenberg

User avatar
Ann
4725 Å
Posts: 13867
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by Ann » Mon Jun 08, 2020 4:09 am

ta152h0 wrote: Mon Jun 08, 2020 2:20 am Earth is a product of accretion of particles over a long time. What makes the center of the Earth a fireball? pass the ice cold one
Doesn't it have to do with radioactive decay in the large iron/nickel core of the Earth?

Ann
Color Commentator

User avatar
johnnydeep
Commodore
Posts: 3257
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by johnnydeep » Mon Jun 08, 2020 3:00 pm

Sa Ji Tario wrote: Sun Jun 07, 2020 4:48 pm ¿Can anyone explain what the spokes are like Japanese parasol rods seen in some images?
I don't seek "spokes" in this image of the cat's eye nebula, rather, there seem to be net-like filaments of denser gas. Not sure what causes that - perhaps magnetic fields? Or maybe it's just random density variations.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

User avatar
johnnydeep
Commodore
Posts: 3257
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by johnnydeep » Mon Jun 08, 2020 3:12 pm

Ann wrote: Mon Jun 08, 2020 4:09 am
ta152h0 wrote: Mon Jun 08, 2020 2:20 am Earth is a product of accretion of particles over a long time. What makes the center of the Earth a fireball? pass the ice cold one
Doesn't it have to do with radioactive decay in the large iron/nickel core of the Earth?

Ann
Yes, plus two other factors. From https://www.scientificamerican.com/arti ... s-core-so/ :
SCIENTIFIC AMERICAN wrote:There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements.
All three phenomena are pretty amazing to me: that there is heat STILL left over from when the Earth formed 4.5 gys ago; that there is any significant amount of FRICTION caused just by slowly sinking rock; and that the core is full of radioactive elements!

The upshot is that were the sun to go dark, we could still survive for quite a long while by digging deep enough. Or at least we would be nice and warm. There's still the not so minor matters of oxygen and food to worry about :-)
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

User avatar
johnnydeep
Commodore
Posts: 3257
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Halo of the Cat's Eye (2020 Jun 07)

Post by johnnydeep » Mon Jun 08, 2020 3:17 pm

ecdowney wrote: Sun Jun 07, 2020 5:17 pm If radius is proportional to time back, it looks like at first there was no rotation (outer third), then equal emission in all directions (middle third), and now leisurely rotation (inner third). Is this a correct interpretation? If so, what caused the change in rotation, perhaps asymmetric emission?
Interesting conjecture. I'm not sure the different appearances of the various layers reflects rotational speed. But, I think it would be true that as material was ejected, it would steal angular momentum from what remained causing it to rotate more slowly?
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}