APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Comments and questions about the APOD on the main view screen.
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APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by APOD Robot » Sun May 10, 2020 4:05 am

Image The Porpoise Galaxy from Hubble

Explanation: What's happening to this spiral galaxy? Just a few hundred million years ago, NGC 2936, the upper of the two large galaxies shown, was likely a normal spiral galaxy -- spinning, creating stars -- and minding its own business. But then it got too close to the massive elliptical galaxy NGC 2937 below and took a dive. Dubbed the Porpoise Galaxy for its iconic shape, NGC 2936 is not only being deflected but also being distorted by the close gravitational interaction. A burst of young blue stars forms the nose of the porpoise toward the right of the upper galaxy, while the center of the spiral appears as an eye. Alternatively, the galaxy pair, together known as Arp 142, look to some like a penguin protecting an egg. Either way, intricate dark dust lanes and bright blue star streams trail the troubled galaxy to the lower right. The featured re-processed image showing Arp 142 in unprecedented detail was taken by the Hubble Space Telescope last year. Arp 142 lies about 300 million light years away toward the constellation, coincidently, of the Water Snake (Hydra). In a billion years or so the two galaxies will likely merge into one larger galaxy.

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Ann » Sun May 10, 2020 5:28 am




















The Porpoise Galaxy? Isn't NGC 2936 more like a penguin than a porpoise? (Besides... a porpoise with one huge egg?)


Okay, so - which way is the cosmic penguin of NGC 2936 looking? Left or right?


















As I googled NGC 2936, the images where the NGC 2936 penguin is looking left won hands down. I think the one at right is my favorite. Yes, you got it, I love the colors, even if I certainly understand that the colors are not "realistic". There's no way that a galaxy full of old stars, like the "Egg" galaxy, NGC 2937, would be cyan-colored.

The only images of NGC 2936/2937 I could find where the penguin is looking right are actually all versions of the one by Raul Villaverde that is today's APOD.










On the other hand, I found images where the penguin was lying on its back, juggling its egg over its tummy.

I guess some penguins like to live dangerously! 🐧 :D

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by AVAO » Sun May 10, 2020 9:27 am

Wow. Great Picture!

For me, it looks as if the "dust body" in the foreground has almost completely separated from the "star body" in the background.
Does anyone have a physical explanation for this?


"If you are lost in space and time - stay cool - and do it with love!" Jac

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Ann » Sun May 10, 2020 9:47 am

AVAO wrote:
Sun May 10, 2020 9:27 am
Wow. Great Picture!

For me, it looks as if the "dust body" in the foreground has almost completely separated from the "star body" in the background.
Does anyone have a physical explanation for this?


"If you are lost in space and time - stay cool - and do it with love!" Jac
Some galaxies do seem to have come apart at their seams.

Wikipedia wrote:

AM 0644-741, also known as the Lindsay-Shapley Ring, is an unbarred lenticular galaxy, and a ring galaxy...

The ring is theorized to have formed by a collision with another galaxy, which triggered a gravitational disruption that caused dust in the galaxy to condense and form stars, which forced it to then expand away from the galaxy and create a ring...

Galactic simulation models suggest that the ring of AM 0644-741 will continue to expand for about another 300 million years, after which it will begin to disintegrate.
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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Eclectic Man » Sun May 10, 2020 12:06 pm

The photograph is superb, but it makes me sad. It is reasonable to assume that each stellar system has its own Oort Cloud, Kuiper belt, and possibly asteroid belt. The orbits of objects in these belts will have been as perturbed as those of the stars in the galaxy, and each and every planet orbiting a star will be pummelled by massive rocks and lumps of ice, reducing any planet-based life to primordial soup, or at best the equivalent of bacteria and tardigrades.

It puts our current problems with Covid-19 into some perspective.

mike hewitt

Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by mike hewitt » Sun May 10, 2020 12:49 pm

WOW!! Was that done on porpoise?

GeoXXXXX

Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by GeoXXXXX » Sun May 10, 2020 1:32 pm

Looks like a long-nosed dolphin!
Image
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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by orin stepanek » Sun May 10, 2020 2:29 pm

PorpoiseGalaxy_HubbleFraile_960.jpg

Wow! That Elliptical Galaxy really disrupting the Spiral; the ol bully! :evil:
It does look as though the Elliptical is not fazed by their passing by!
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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Chris Peterson » Sun May 10, 2020 2:35 pm

Eclectic Man wrote:
Sun May 10, 2020 12:06 pm
The photograph is superb, but it makes me sad. It is reasonable to assume that each stellar system has its own Oort Cloud, Kuiper belt, and possibly asteroid belt. The orbits of objects in these belts will have been as perturbed as those of the stars in the galaxy, and each and every planet orbiting a star will be pummelled by massive rocks and lumps of ice, reducing any planet-based life to primordial soup, or at best the equivalent of bacteria and tardigrades.

It puts our current problems with Covid-19 into some perspective.
Look at the structure created by the interaction, and you can see how the tidal forces create distortion over very long distances. So large regions of the galaxy are subjected to very similar forces with very long-baseline gradients. What that means is that locally, regions will remain largely unchanged over a scale of many light years. Which means that most planetary systems will be largely unaffected.
Chris

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Cousin Ricky » Sun May 10, 2020 3:41 pm

It looks totally like a penguin.

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by johnnydeep » Sun May 10, 2020 4:50 pm

This porpoise looks more like a hummingbird to me.

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by AVAO » Sun May 10, 2020 7:24 pm

Ann wrote:
Sun May 10, 2020 9:47 am
AVAO wrote:
Sun May 10, 2020 9:27 am
Wow. Great Picture!

For me, it looks as if the "dust body" in the foreground has almost completely separated from the "star body" in the background.
Does anyone have a physical explanation for this?


"If you are lost in space and time - stay cool - and do it with love!" Jac
Some galaxies do seem to have come apart at their seams.

Wikipedia wrote:

AM 0644-741, also known as the Lindsay-Shapley Ring, is an unbarred lenticular galaxy, and a ring galaxy...

The ring is theorized to have formed by a collision with another galaxy, which triggered a gravitational disruption that caused dust in the galaxy to condense and form stars, which forced it to then expand away from the galaxy and create a ring...

Galactic simulation models suggest that the ring of AM 0644-741 will continue to expand for about another 300 million years, after which it will begin to disintegrate.
Ann
[/quote]

Thanks, I think you're right. The situation looks extremely similar. In both cases, I think we see a dive into the center of the nearby larger elliptical galaxy.

look at:
https://apod.nasa.gov/apod/ap180917.html
Image
Image

Jac
[/quote]

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by APODFORIST » Mon May 11, 2020 9:45 am

This image is very similar to what astronaut Dave Bowman in 2001: A Space Odyssey sees when he is pulled into new dimensions.
-> Stanley Kubrick was a genius.

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Eclectic Man » Mon May 11, 2020 11:46 am

Chris Peterson wrote:
Sun May 10, 2020 2:35 pm
Eclectic Man wrote:
Sun May 10, 2020 12:06 pm
The photograph is superb, but it makes me sad. It is reasonable to assume that each stellar system has its own Oort Cloud, Kuiper belt, and possibly asteroid belt. The orbits of objects in these belts will have been as perturbed as those of the stars in the galaxy, and each and every planet orbiting a star will be pummelled by massive rocks and lumps of ice, reducing any planet-based life to primordial soup, or at best the equivalent of bacteria and tardigrades.

It puts our current problems with Covid-19 into some perspective.
Look at the structure created by the interaction, and you can see how the tidal forces create distortion over very long distances. So large regions of the galaxy are subjected to very similar forces with very long-baseline gradients. What that means is that locally, regions will remain largely unchanged over a scale of many light years. Which means that most planetary systems will be largely unaffected.
Interesting argument. The late 'great bombardment' of the Earth was reputedly caused by a star passing close by to the solar system and perturbing the Oort Cloud and Kuiper belt, is it really the case that solar system objects are so closely bound to the star that distortions such as those seen in the Dolphin galaxy have little to no effect?

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Re: APOD: The Porpoise Galaxy from Hubble (2020 May 10)

Post by Chris Peterson » Mon May 11, 2020 1:33 pm

Eclectic Man wrote:
Mon May 11, 2020 11:46 am
Chris Peterson wrote:
Sun May 10, 2020 2:35 pm
Eclectic Man wrote:
Sun May 10, 2020 12:06 pm
The photograph is superb, but it makes me sad. It is reasonable to assume that each stellar system has its own Oort Cloud, Kuiper belt, and possibly asteroid belt. The orbits of objects in these belts will have been as perturbed as those of the stars in the galaxy, and each and every planet orbiting a star will be pummelled by massive rocks and lumps of ice, reducing any planet-based life to primordial soup, or at best the equivalent of bacteria and tardigrades.

It puts our current problems with Covid-19 into some perspective.
Look at the structure created by the interaction, and you can see how the tidal forces create distortion over very long distances. So large regions of the galaxy are subjected to very similar forces with very long-baseline gradients. What that means is that locally, regions will remain largely unchanged over a scale of many light years. Which means that most planetary systems will be largely unaffected.
Interesting argument. The late 'great bombardment' of the Earth was reputedly caused by a star passing close by to the solar system and perturbing the Oort Cloud and Kuiper belt, is it really the case that solar system objects are so closely bound to the star that distortions such as those seen in the Dolphin galaxy have little to no effect?
I'm sure that close passing stars can perturb the outer parts of stellar systems and cause periods of bombardment in those systems. I just don't think tidal distortions like we see here are likely to result in "rogue" stars in very many places, because stars largely travel together, and those that are only a few light years apart are going to experience virtually identical tidal forces, and will therefore move together.
Chris

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