APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Comments and questions about the APOD on the main view screen.
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neufer
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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by neufer » Thu May 30, 2013 2:23 am

Beyond wrote:
neufer wrote:
Meaning that the magnetic field
runs from the top to the bottom in: ...
Even in front of a mirror turned sideways :?: :?:

No... but parity conservation then requires
that the atomic hydrogen move clockwise.
http://www.flickr.com/photos/22611996@N02/6218610907/ wrote:
:arrow: <<This is my lino-cut portrait of Chien-Shiung Wu, her reflection (as in a mirror) and a schematic of her famous 1956 experiment which showed that unlike anything else, the weak force isn't the same if you reflect the set-up in the mirror (it isn't spatially invariant, it violates parity). She place radioactive Cobalt-60 in a strong magnetic field and showed that the emitted beta decay electrons went preferentially in one direction (shown as down towards the North pole of the electromagnet in the box on the left). When the mirror reflection of the experiment was performed, the emitted electrons go preferentially in the OPPOSITE direction (up towards the North pole of the electromagnet in the right side schematic).>>
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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by Beyond » Thu May 30, 2013 3:02 am

Well how about that :!: The mirror doesn't even need to be turned sideways. A straight on reflection is enough. Who wudda thought :?: It looks like even the itty-bitty things get confused by a mirror. :lol2: Hmm... people think their right and left sides get reversed, but the itty-bitty things get their up and down reversed. Sure is strange.
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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by alter-ego » Thu May 30, 2013 4:25 am

neufer wrote:
stephen63 wrote:
neufer wrote:
As the different plasmas passed through:
  • 1) the remnant dipole field of the exploded star
    2) and/or the residual galactic magnetic field
the atomic hydrogen (red) curved in a counter-clockwise direction more than the doubly ionized oxygen
(about a northerly directed axis).
For us dummies(specifically me),
does that follow the right hand rule?
http://www.magnet.fsu.edu/education/tut ... handrules/
  • For all of us, actually.
Meaning that the magnetic field runs from the top to the bottom in: http://apod.nasa.gov/apod/ap121126.html
------------------------------------------------------------------------------------
Note: Red blue glasses actually make the closer components of:
http://apod.nasa.gov/apod/ap121126.html appear to be closer :!:
I don't understand the role the B-field is that you're implying. The colored layers simply reflect the radial shock-front energy distribution where the atomic oxygen emission reveals that shell as the highest-energy, leading edge of the SN explosion, and hydrogen emission being the cooler emission following the shock wave. I'm not saying that magnetic fields don't exist in those regions, just that they are not needed to explain the emissions visible in the picture. Analogously, the higher-energy, SN1006 APOD shows the same shock-wave phenomenon but in the X-ray regime instead of the visible. I find the magnetic field discussion irrelevant and confusing to answer retrogalax's question about why the blue layer is where it is.
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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by neufer » Thu May 30, 2013 5:26 am

alter-ego wrote:
I don't understand the role the B-field is that you're implying. The colored layers simply reflect the radial shock-front energy distribution where the atomic oxygen emission reveals that shell as the highest-energy, leading edge of the SN explosion, and hydrogen emission being the cooler emission following the shock wave. I'm not saying that magnetic fields don't exist in those regions, just that they are not needed to explain the emissions visible in the picture. Analogously, the higher-energy, SN1006 APOD shows the same shock-wave phenomenon but in the X-ray regime instead of the visible.
SN1006 APOD is analogous because the blue color is on the outside?

Does blue always go on the outside? [What about rainbows? http://apod.nasa.gov/apod/ap110814.html ]
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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by alter-ego » Thu May 30, 2013 5:48 am

neufer wrote:
alter-ego wrote:
I don't understand the role the B-field is that you're implying. The colored layers simply reflect the radial shock-front energy distribution where the atomic oxygen emission reveals that shell as the highest-energy, leading edge of the SN explosion, and hydrogen emission being the cooler emission following the shock wave. I'm not saying that magnetic fields don't exist in those regions, just that they are not needed to explain the emissions visible in the picture. Analogously, the higher-energy, SN1006 APOD shows the same shock-wave phenomenon but in the X-ray regime instead of the visible.
SN1006 APOD is analogous because the blue color is on the outside?

Does blue always go on the outside? [What about rainbows? http://apod.nasa.gov/apod/ap110814.html ]
Yeah, you gotta watch out for those rainbow shock fronts, they'll fool ya everytime :wink:
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retrogalax

Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by retrogalax » Thu May 30, 2013 9:22 pm

I didn't think of the magnetic effect.I see the counter clockwise flexion (looking at the western and the eastern areas with the magnetic field orientation), thank you Art for the explanation.

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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by Darwins » Tue Jul 29, 2014 5:05 pm

Beautiful picture. Is the part I have circled in yellow the supernova?

Image

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Re: APOD: NGC 6960: The Witch's Broom Nebula (2013 May 29)

Post by geckzilla » Tue Jul 29, 2014 5:57 pm

Darwins wrote:Beautiful picture. Is the part I have circled in yellow the supernova?

Image
No. The progenitor is off the frame somewhere.
http://en.wikipedia.org/wiki/Cygnus_Loop
If you scroll down you can see an annotated image which denotes the approximate center. Whatever's left of the star ought to be there. It's not obvious.
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