APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

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APOD Robot
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APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby APOD Robot » Tue Feb 06, 2018 5:06 am

Image Galaxy NGC 474: Shells and Star Streams

Explanation: What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex and unexpected given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause of the shells is currently unknown, but possibly tidal tails related to debris left over from absorbing numerous small galaxies in the past billion years. Alternatively the shells may be like ripples in a pond, where the ongoing collision with the spiral galaxy just above NGC 474 is causing density waves to ripple through the galactic giant. Regardless of the actual cause, the featured image dramatically highlights the increasing consensus that at least some elliptical galaxies have formed in the recent past, and that the outer halos of most large galaxies are not really smooth but have complexities induced by frequent interactions with -- and accretions of -- smaller nearby galaxies. The halo of our own Milky Way Galaxy is one example of such unexpected complexity. NGC 474 spans about 250,000 light years and lies about 100 million light years distant toward the constellation of the Fish (Pisces).

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Boomer12k
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Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby Boomer12k » Tue Feb 06, 2018 7:22 am

Awesome....looks like a clear, plastic webcamera.... "The Webcam Galaxy"... :lol2:

IT also looks like another small galaxy has passed just "beneath" it...the bluer part... it looks like it was going over the top of, or just in front of the main part, and was disrupted.... parts, left and right, appear to be "dropping inward" towards the main part....it may be a small satellite has been "captured"....

nice job....

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NCTom

Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby NCTom » Tue Feb 06, 2018 12:01 pm

Fascinating picture, but my ignorance really comes through on understanding some of the visual effects. Star spikes are one thing, but so many halos around our galactic stars? Something about the image just looks different. I checked the CFHT site and this is a July 2013 calendar shot, but it gave no details I could find about the tech side.

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Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby neufer » Tue Feb 06, 2018 7:21 pm

Click to play embedded YouTube video.
Art Neuendorffer

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Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby Spicy Meatball » Tue Feb 06, 2018 9:35 pm

Am i the only one who sees the galaxy looking like an orb with a blue trail?
Plus a name if you can see it, "Wandering Orb" Galaxy. Eh?

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Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby Boomer12k » Tue Feb 06, 2018 10:52 pm

Spicy Meatball wrote:Am i the only one who sees the galaxy looking like an orb with a blue trail?
Plus a name if you can see it, "Wandering Orb" Galaxy. Eh?


No, you are not... I think it too is a separate small galaxy that is in collision....and got torn, and splayed out...it is the "Stand" for my "Webcam Galaxy".... lol...

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sillyworm2

Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby sillyworm2 » Wed Feb 07, 2018 4:46 pm

Amazing I will be looking for more pictures of this Beautiful "merging/dance".

APOD Fanboy

Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby APOD Fanboy » Thu Feb 08, 2018 1:54 pm

The "unexpected complexity" was wonderful, truly funny, and definitely unexpected. I can't recall any earlier humor from APOD, except maybe on April 1 posts. Not only was it unexpected, it could be seen as a representation of the early stage of planetary formation, with a central object surrounded by chaotic debris. Well done APOD.

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Re: APOD: Galaxy NGC 474: Shells and Star Streams (2018 Feb 06)

Postby Chris Peterson » Thu Feb 08, 2018 2:55 pm

APOD Fanboy wrote:Not only was it unexpected, it could be seen as a representation of the early stage of planetary formation, with a central object surrounded by chaotic debris.

Is that your own effort at humor?
Chris

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