Starship Asterisk*

[quote="whwiii"]was hoping someone could help me explain what's moving in my images of the heart of the crab nebula
is it electrons moving at relativistic speed?[/quote]
Most likely. The nebula is highly shocked, which is seen in its structure. As charged particles encounter denser regions, the resulting ionization should produce brighter zones. It is also possible we see moving shock boundaries, which can propagate at relativistic speeds even though the actual material itself is only moving on the order of 1000 km/s.

[b][i] http://asterisk.apod.com/viewtopic.php?f=9&t=23736 [/i][/b]
[b][i] http://asterisk.apod.com/viewtopic.php?f=31&t=23695 [/i][/b]
[b][i] http://asterisk.apod.com/viewtopic.php?f=31&t=23093 [/i][/b]
[b][i] http://asterisk.apod.com/viewtopic.php?f=31&t=21399 [/i][/b]

Chris, Art, Rob and others who understand photography and who have a reasonable understanding of the Crab Nebula, please help out here! Bill's pictures are very interesting, but the nebular remnants of dead stars aren't quite my thing. So I can't offer much of an opinion. It is certainly well known that the pulsar inside the Crab nebula is really acting up and causing changes in the Crab, but that is about as much as I know myself.

So please take a look at Bill's pictures and tell him what you think he has photographed! If possible, try to answer his questions, too!

Ann

hiya
was hoping someone could help me explain what's moving in my images of the heart of the crab nebula
is it electrons moving at relativistic speed?

originally submitted to the photography forum

here's the short version:
this past winter i shot multiple images of the crab nebula
and detected motion at the core over a short time interval (1-2 months or less):
[img2]http://whwastro.homestead.com/files/big/crab-2-months-blink-800w.gif[/img2]

here's a grey scale linear stretch for the purisits
[img2]http://whwastro.homestead.com/files/M1-core-linear-blink-300.gif[/img2]

quick calculation:
the crab nebula is 6,000 light years away.
2 good frames taken one month apart show bright wisp motion of 2 pixels in x and y at an image scale of .57 arcsec/px
sin(2.8 px x .57 "/px) x 6000 Ly / (1/12)y = .56 speed of light!
speed of electrons in the crab is quoted as about .5c
QED
OK i'm not really sure the moving wisps represent moving electrons

so what is moving here? does the motion really correspond light released due to electrons moving across the space as measured in my images?

full post with interesting musings and narrow band images here
http://asterisk.apod.com/viewtopic.php?f=29&t=22862&p=152933#p152762
have read thru the following references which were quite helpful but don't quite answer it for me:

ref:
J. J. Hester, “The Crab Nebula: An Astrophysical Chimera”, Annual Review of Astronomy and Astrophysics, 46, 127-155 (2008).
Donald E. Osterbrock, Gary J. Ferland, Astrophysics Of Gaseous Nebulae And Active Galactic Nuclei.

thanks

-bill w