APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

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APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by APOD Robot » Fri Jul 08, 2016 4:08 am

Image The Swirling Core of the Crab Nebula

Explanation: At the core of the Crab Nebula lies a city-sized, magnetized neutron star spinning 30 times a second. Known as the Crab Pulsar, it's actually the rightmost of two bright stars, just below a central swirl in this stunning Hubble snapshot of the nebula's core. Some three light-years across, the spectacular picture frames the glowing gas, cavities and swirling filaments bathed in an eerie blue light. The blue glow is visible radiation given off by electrons spiraling in a strong magnetic field at nearly the speed of light. Like a cosmic dynamo the pulsar powers the emission from the nebula, driving a shock wave through surrounding material and accelerating the spiraling electrons. With more mass than the Sun and the density of an atomic nucleus, the spinning pulsar is the collapsed core of a massive star that exploded. The Crab Nebula is the expanding remnant of the star's outer layers. The supernova explosion was witnessed on planet Earth in the year 1054.

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by bystander » Fri Jul 08, 2016 5:05 am

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by heehaw » Fri Jul 08, 2016 9:07 am

As a postdoc, working for Herb Friedman at NRL, I got to go to White Sands for a rocket launch to observe the Crab in X-rays, and to write my own Fourier Analysis program in fortran to analyze the data, and to detect the pulsar pulses in X-rays for the first time, and get my plot on the cover of Science magazine! How I love the Crab nebula!

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by neufer » Fri Jul 08, 2016 11:37 am

heehaw wrote:
As a postdoc, working for Herb Friedman at NRL, I got to go to White Sands for a rocket launch to observe the Crab in X-rays, and to write my own Fourier Analysis program in fortran to analyze the data, and to detect the pulsar pulses in X-rays for the first time, and get my plot on the cover of Science magazine! How I love the Crab nebula!
Can you post a copy of the Science magazine cover :?:

(I did my own Fourier Analysis in FORTRAN to analyze White Sands turbulent wind data but it never made it to any magazine cover.)
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by Joules » Fri Jul 08, 2016 1:15 pm

Looks like there's some serious energy there.
3 light years seems a little too close.
I think I'd rather stand within 3 feet of a mile long coal train doing 60mph.

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by Fred the Cat » Fri Jul 08, 2016 2:27 pm

Do the planes of the cosmic dynamo spin in opposite directions? I've wondered if two spinning objects of equal mass spinning in opposite directions would net a zero momentum. :?: Seems if they are on the same plane they would cancel total momentum and that would be a unique state. :idea:
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by neufer » Fri Jul 08, 2016 3:40 pm

Fred the Cat wrote:
Do the planes of the cosmic dynamo spin in opposite directions? I've wondered if two spinning objects of equal mass spinning in opposite directions would net a zero momentum. :?: Seems if they are on the same plane they would cancel total momentum and that would be a unique state. :idea:
I assume that you mean:
if they are on the same plane they would cancel total angular momentum and that would be a unique state.
In the model, there are two separate planes (with roughly the same angular momentum) only because the magnetic axis (M) and the spin axis (Omega) of the neutron star are not aligned. If these axes were aligned then the two planes would merge into a single plane.

http://chandra.harvard.edu/chronicle/0201/vela.html
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by Fred the Cat » Fri Jul 08, 2016 4:12 pm

neufer wrote:[I assume that you mean:
if they are on the same plane they would cancel total angular momentum and that would be a unique state.
http://chandra.harvard.edu/chronicle/0201/vela.html
Yes. Today's APOD triggered a thought I've have been curious about for some time. I've wondered if someone with the technical ability has constructed a device comprised of two oppositely spinning circular planes of equal mass where the central mass drove, via an externally coupled helical gear, an outer mass in the opposite direction. In this both masses would angularly spin oppositely and I was curious of the effect it might have. The link of the mechanism of the inner workings of the Crab Nebula seemed similar.
Last edited by Fred the Cat on Fri Jul 08, 2016 4:45 pm, edited 3 times in total.
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by Ann » Fri Jul 08, 2016 4:14 pm

heehaw wrote:As a postdoc, working for Herb Friedman at NRL, I got to go to White Sands for a rocket launch to observe the Crab in X-rays, and to write my own Fourier Analysis program in fortran to analyze the data, and to detect the pulsar pulses in X-rays for the first time, and get my plot on the cover of Science magazine! How I love the Crab nebula!
I'm impressed, heehaw!

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heehaw

Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by heehaw » Fri Jul 08, 2016 4:45 pm

neufer wrote:
heehaw wrote:
As a postdoc, working for Herb Friedman at NRL, I got to go to White Sands for a rocket launch to observe the Crab in X-rays, and to write my own Fourier Analysis program in fortran to analyze the data, and to detect the pulsar pulses in X-rays for the first time, and get my plot on the cover of Science magazine! How I love the Crab nebula!
Can you post a copy of the Science magazine cover :?:

(I did my own Fourier Analysis in FORTRAN to analyze White Sands turbulent wind data but it never made it to any magazine cover.)
http://henry.pha.jhu.edu/ThomasHenryFol ... Henry.html

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by Boomer12k » Fri Jul 08, 2016 5:04 pm

That is just awesome... it would be interesting to see animation of this area...

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by heehaw » Fri Jul 08, 2016 7:47 pm

Ann wrote:
heehaw wrote: I'm impressed, heehaw!
Ann
I am ALWAYS impressed, Ann, with what YOU do, every day, for all of us!

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by neufer » Fri Jul 08, 2016 8:18 pm

I was stationed out at White Sands in May, 1969.
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by BT7design » Fri Jul 08, 2016 9:11 pm

Am curious. Image caption states the pulsar itself is "one of the two bright stars" etc.
If it is 'city-sized', wouldnt it be quite dim compared to nearby stars? Or does the unreal radiation and such
make up for that?

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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by neufer » Fri Jul 08, 2016 10:23 pm

BT7design wrote:
Image caption states the pulsar itself is "one of the two bright stars" etc.
If it is 'city-sized', wouldn't it be quite dim compared to nearby stars?
Or does the unreal radiation and such make up for that?
  • Non-thermal variable "unreal" radiation does make up for that.

    But the nearby stars are also quite dim (apparent magnitude ~ 16.5).
https://en.wikipedia.org/wiki/Crab_Nebula#Central_star wrote: <<At the centre of the Crab Nebula are two faint stars, one of which is the star responsible for the existence of the nebula. It was identified as such in 1942, when Rudolf Minkowski found that its optical spectrum was extremely unusual. The region around the star was found to be a strong source of radio waves in 1949 and X-rays in 1963, and was identified as one of the brightest objects in the sky in gamma rays in 1967. Then, in 1968, the star was found to be emitting its radiation in rapid pulses, becoming one of the first pulsars to be discovered.>>
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Re: APOD: The Swirling Core of the Crab Nebula (2016 Jul 08)

Post by Ann » Sat Jul 09, 2016 8:36 am

heehaw wrote:
Ann wrote:
heehaw wrote: I'm impressed, heehaw!
Ann
I am ALWAYS impressed, Ann, with what YOU do, every day, for all of us!
Thanks so much, heehaw!

Ann
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