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APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Wed Aug 03, 2022 4:10 am
by APOD Robot
Image Halo of the Cat's Eye

Explanation: What created the unusual halo around the Cat's Eye nebula? No one is sure. What is sure is that the Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae on the sky. Although haunting symmetries are seen in the bright central region, this image was taken to feature its intricately structured outer halo, which spans over three light-years across. Planetary nebulae have long been appreciated as a final phase in the life of a Sun-like star. Only recently however, have some planetaries been found to have expansive halos, likely formed from material shrugged off during earlier puzzling 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 the Cat's Eye Nebula's halo to be 50,000 to 90,000 years.

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Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Wed Aug 03, 2022 12:41 pm
by orin stepanek
CatsHalo_Falls_2719.jpg
Fantastic; halo of Cat's Eye! 8-)
CatsEye_HubblePohl_960.jpg
Cat's eye nebula!
I love the Cat's Eye; A very nice nebula; but the Halo is even nicer!
It is so intricate; so delicate; like the very nicest doilies ever! better
than man can create! IMO! :mrgreen:

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Wed Aug 03, 2022 9:12 pm
by heehaw
When this happens to our Sun, which it will in ~5 billion years, I wonder if pictures of it will be pondered by 'people' on other worlds?

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 1:32 am
by De58te
heehaw wrote: Wed Aug 03, 2022 9:12 pm When this happens to our Sun, which it will in ~5 billion years, I wonder if pictures of it will be pondered by 'people' on other worlds?
I would think so. My great grandmother said to me in July 1969. "When she was born 75 years ago they were riding around by horse and buggy, and the Wright brothers hadn't invented the aeroplane yet! Now this week she witnessed a man land on the Moon!" If mankind can do that in less than 100 years, can you just imagine what they can do in 5 billion years! I feel positive that Earthlings will have discovered space travel by then and are living on planets around Alpha Centauri and other stars, and they will look surely back with nostalgia at the death of the Sun.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 1:42 am
by Chris Peterson
De58te wrote: Thu Aug 04, 2022 1:32 am
heehaw wrote: Wed Aug 03, 2022 9:12 pm When this happens to our Sun, which it will in ~5 billion years, I wonder if pictures of it will be pondered by 'people' on other worlds?
I would think so. My great grandmother said to me in July 1969. "When she was born 75 years ago they were riding around by horse and buggy, and the Wright brothers hadn't invented the aeroplane yet! Now this week she witnessed a man land on the Moon!" If mankind can do that in less than 100 years, can you just imagine what they can do in 5 billion years! I feel positive that Earthlings will have discovered space travel by then and are living on planets around Alpha Centauri and other stars, and they will look surely back with nostalgia at the death of the Sun.
I feel positive that humans will be long extinct by then. Technological civilizations have short lifetimes. The Universe is made for algae.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 4:06 am
by Ann
orin stepanek wrote: Wed Aug 03, 2022 12:41 pm Fantastic; halo of Cat's Eye! 8-) Cat's eye nebula!
I love the Cat's Eye; A very nice nebula; but the Halo is even nicer!
It is so intricate; so delicate; like the very nicest doilies ever! better
than man can create! IMO! :mrgreen:
Doily. Photograph by Kathy A. Graff.


Thanks for teaching me a new word, Orin! That's the drawback of not living in the country whose language you speak. There are a lot of little everyday items whose names and designations you don't pick up.

And soon, I fear, I will have forgotten "doily" again. Doily? What's that?

Ann

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 4:08 am
by Chris Peterson
Ann wrote: Thu Aug 04, 2022 4:06 am
orin stepanek wrote: Wed Aug 03, 2022 12:41 pm
Cat's eye nebula!
I love the Cat's Eye; A very nice nebula; but the Halo is even nicer!
It is so intricate; so delicate; like the very nicest doilies ever! better
than man can create! IMO! :mrgreen:

Thanks for teaching me a new word, Orin! That's the drawback of not living in the country whose language you speak. There are a lot of little everyday items whose names and designations you don't pick up.

And soon, I fear, I will have forgotten "doily" again. Doily? What's that?

Ann
Familiarity with doilies is likely related to being of a certain age, sufficient to have had a grandmother of a certain age.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 12:11 pm
by orin stepanek
Chris Peterson wrote: Thu Aug 04, 2022 4:08 am
Ann wrote: Thu Aug 04, 2022 4:06 am
orin stepanek wrote: Wed Aug 03, 2022 12:41 pm
Cat's eye nebula!
I love the Cat's Eye; A very nice nebula; but the Halo is even nicer!
It is so intricate; so delicate; like the very nicest doilies ever! better
than man can create! IMO! :mrgreen:

Thanks for teaching me a new word, Orin! That's the drawback of not living in the country whose language you speak. There are a lot of little everyday items whose names and designations you don't pick up.

And soon, I fear, I will have forgotten "doily" again. Doily? What's that?

Ann
Familiarity with doilies is likely related to being of a certain age, sufficient to have had a grandmother of a certain age.
Yup; I am an old fart! doilies were fanciful during their time! :mrgreen:

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 2:06 pm
by johnnydeep
Chris Peterson wrote: Thu Aug 04, 2022 1:42 am
De58te wrote: Thu Aug 04, 2022 1:32 am
heehaw wrote: Wed Aug 03, 2022 9:12 pm When this happens to our Sun, which it will in ~5 billion years, I wonder if pictures of it will be pondered by 'people' on other worlds?
I would think so. My great grandmother said to me in July 1969. "When she was born 75 years ago they were riding around by horse and buggy, and the Wright brothers hadn't invented the aeroplane yet! Now this week she witnessed a man land on the Moon!" If mankind can do that in less than 100 years, can you just imagine what they can do in 5 billion years! I feel positive that Earthlings will have discovered space travel by then and are living on planets around Alpha Centauri and other stars, and they will look surely back with nostalgia at the death of the Sun.
I feel positive that humans will be long extinct by then. Technological civilizations have short lifetimes. The Universe is made for algae.
I took the original question to be about whether a "people", that is, a technological civilization not related to humans, living on some other planet orbiting some other star, would be seeing our Sun explode and "pondering" upon it. I think that is a much(*) more likely scenario than that we humans will be around in 5 Gy to be able to do the same. Of course, even if "we humans" are still around then, we won't be anything like what we are now!

(*) - As for how likely there are - or ever were, or ever will be - ANY other advanced technological civilizations in the universe besides us, that is a very debatable topic. :ssmile: For purely romantic reasons, I'd like to believe that "we are not alone", but it's pretty hard to draw any conclusions from a single data point.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 2:09 pm
by Chris Peterson
johnnydeep wrote: Thu Aug 04, 2022 2:06 pm
Chris Peterson wrote: Thu Aug 04, 2022 1:42 am
De58te wrote: Thu Aug 04, 2022 1:32 am

I would think so. My great grandmother said to me in July 1969. "When she was born 75 years ago they were riding around by horse and buggy, and the Wright brothers hadn't invented the aeroplane yet! Now this week she witnessed a man land on the Moon!" If mankind can do that in less than 100 years, can you just imagine what they can do in 5 billion years! I feel positive that Earthlings will have discovered space travel by then and are living on planets around Alpha Centauri and other stars, and they will look surely back with nostalgia at the death of the Sun.
I feel positive that humans will be long extinct by then. Technological civilizations have short lifetimes. The Universe is made for algae.
I took the original question to be about whether a "people", that is, a technological civilization not related to humans, living on some other planet orbiting some other star, would be seeing our Sun explode and "pondering" upon it. I think that is a much(*) more likely scenario than that we humans will be around in 5 Gy to be able to do the same. Of course, even if "we humans" are still around then, we won't be anything like what we are now!

(*) - As for how likely there are - or ever were, or ever will be - ANY other advanced technological civilizations in the universe besides us, that is a very debatable topic. :ssmile: For purely romantic reasons, I'd like to believe that "we are not alone", but it's pretty hard to draw any conclusions from a single data point.
I very much doubt we're alone. But I don't imagine it's likely that any other (brief) technological species that happen to overlap our own (brief) technological species are close enough to detect. If the like of us only last a few thousand years, which seems likely, there can't be many at any one time.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 2:26 pm
by johnnydeep
Chris Peterson wrote: Thu Aug 04, 2022 2:09 pm
johnnydeep wrote: Thu Aug 04, 2022 2:06 pm
Chris Peterson wrote: Thu Aug 04, 2022 1:42 am

I feel positive that humans will be long extinct by then. Technological civilizations have short lifetimes. The Universe is made for algae.
I took the original question to be about whether a "people", that is, a technological civilization not related to humans, living on some other planet orbiting some other star, would be seeing our Sun explode and "pondering" upon it. I think that is a much(*) more likely scenario than that we humans will be around in 5 Gy to be able to do the same. Of course, even if "we humans" are still around then, we won't be anything like what we are now!

(*) - As for how likely there are - or ever were, or ever will be - ANY other advanced technological civilizations in the universe besides us, that is a very debatable topic. :ssmile: For purely romantic reasons, I'd like to believe that "we are not alone", but it's pretty hard to draw any conclusions from a single data point.
I very much doubt we're alone. But I don't imagine it's likely that any other (brief) technological species that happen to overlap our own (brief) technological species are close enough to detect. If the like of us only last a few thousand years, which seems likely, there can't be many at any one time.
Yup, the overlapping time window problem is very real. But we still have only one data point for how long advanced civilizations last, namely us at our present state of development. I don't really consider past "advanced" civilizations to be examples since they weren't as advanced as we are technologically, but that could just be personal bias speaking. We could very well be more likely to annihilate ourselves sooner than any past civilization did.

But in the case of some other civilization detecting our Sun exploding, we get multiple time windows to overlap with since the speed of light is not infinite! That is, the light from our Sun exploding gets many chances to reach different windows at different distances from us as it travels ever farther outward.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 2:32 pm
by Chris Peterson
johnnydeep wrote: Thu Aug 04, 2022 2:26 pm
Chris Peterson wrote: Thu Aug 04, 2022 2:09 pm
johnnydeep wrote: Thu Aug 04, 2022 2:06 pm

I took the original question to be about whether a "people", that is, a technological civilization not related to humans, living on some other planet orbiting some other star, would be seeing our Sun explode and "pondering" upon it. I think that is a much(*) more likely scenario than that we humans will be around in 5 Gy to be able to do the same. Of course, even if "we humans" are still around then, we won't be anything like what we are now!

(*) - As for how likely there are - or ever were, or ever will be - ANY other advanced technological civilizations in the universe besides us, that is a very debatable topic. :ssmile: For purely romantic reasons, I'd like to believe that "we are not alone", but it's pretty hard to draw any conclusions from a single data point.
I very much doubt we're alone. But I don't imagine it's likely that any other (brief) technological species that happen to overlap our own (brief) technological species are close enough to detect. If the like of us only last a few thousand years, which seems likely, there can't be many at any one time.
Yup, the overlapping time window problem is very real. But we still have only one data point for how long advanced civilizations last, namely us at our present state of development. I don't really consider past "advanced" civilizations to be examples since they weren't as advanced as we are technologically, but that could just be personal bias speaking. We could very well be more likely to annihilate ourselves sooner than any past civilization did.

But in the case of some other civilization detecting our Sun exploding, we get multiple time windows to overlap with since the speed of light is not infinite! That is, the light from our Sun exploding gets many chances to reach different windows at different distances from us as it travels ever farther outward.
Well, the demise of the Sun isn't going to be very impressive. Not a supernova, so most likely something that will only be observable from within our own galaxy, and likely only parts of the galaxy. So that drops the observation window down to something on the order of 100,000 years, which probably isn't much different from zero when considering advanced technological observers.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Thu Aug 04, 2022 3:24 pm
by johnnydeep
Chris Peterson wrote: Thu Aug 04, 2022 2:32 pm
johnnydeep wrote: Thu Aug 04, 2022 2:26 pm
Chris Peterson wrote: Thu Aug 04, 2022 2:09 pm

I very much doubt we're alone. But I don't imagine it's likely that any other (brief) technological species that happen to overlap our own (brief) technological species are close enough to detect. If the like of us only last a few thousand years, which seems likely, there can't be many at any one time.
Yup, the overlapping time window problem is very real. But we still have only one data point for how long advanced civilizations last, namely us at our present state of development. I don't really consider past "advanced" civilizations to be examples since they weren't as advanced as we are technologically, but that could just be personal bias speaking. We could very well be more likely to annihilate ourselves sooner than any past civilization did.

But in the case of some other civilization detecting our Sun exploding, we get multiple time windows to overlap with since the speed of light is not infinite! That is, the light from our Sun exploding gets many chances to reach different windows at different distances from us as it travels ever farther outward.
Well, the demise of the Sun isn't going to be very impressive. Not a supernova, so most likely something that will only be observable from within our own galaxy, and likely only parts of the galaxy. So that drops the observation window down to something on the order of 100,000 years, which probably isn't much different from zero when considering advanced technological observers.
Good point.

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Fri Aug 05, 2022 5:12 am
by MarkBour
Chris Peterson wrote: Thu Aug 04, 2022 1:42 am ... The Universe is made for algae.
How about whales?

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Fri Aug 05, 2022 12:12 pm
by johnnydeep
MarkBour wrote: Fri Aug 05, 2022 5:12 am
Chris Peterson wrote: Thu Aug 04, 2022 1:42 am ... The Universe is made for algae.
How about whales?
Yes, whales are made for algae too :wink:

Re: APOD: Halo of the Cat's Eye (2022 Aug 03)

Posted: Sat Aug 06, 2022 5:46 pm
by MarkBour
johnnydeep wrote: Fri Aug 05, 2022 12:12 pm
MarkBour wrote: Fri Aug 05, 2022 5:12 am
Chris Peterson wrote: Thu Aug 04, 2022 1:42 am ... The Universe is made for algae.
How about whales?
Yes, whales are made for algae too :wink:
:lol2: