what caused this?

Question

http://heritage.stsci.edu/2007/30/index.html

I'm totally entranced with this Veil Nebula.... but what forces, solar 'winds', star explosions, etc, whatEVER, would leave dust in such graceful tracings as these?.... do they move as the astronomers take successive pictures of them over the years?.....

thanks jjjnetti... can't see the movie, but looked up the 'shell'... lovely!!!... I guess then, that the older the nebula the more dispersed it would be then, and the more 'ethereal'?.... not clumpy like Eagle?...

Answer 1

Hello.

Yes, the Veil Nebula is very famous and beautiful. It is the remnants of a star which exploded about 5,000 years ago as a supernova. This is the explosion which occurs, when a massive star explodes due to the rapid and runaway exhaustion of its hydrogen fuel, then Helium and other elements progressively heavier are fused through nuclear reactions through the periodic table up to to Iron.

When that happens and no further nuclear reactions can take place, then the pressure keeping the star in equlibrium apidly vanishes and the star collapses into the iron core. It is the rebound shockwave of that collapse which causes a gigantic explosion and results in the star being blown to smithereens with stupending energy including the expulsion of almost all of the matter of the star creating expanding clouds which eventually disperse into space.

Supernovae have been known to emit more light and other energy than the entire galaxy in which they reside for many days after and can be seen as a star brighter than Venus in broad daylight,

These clouds move at speeds which exceed 5,000km per second, but normally disperse over a period of tens of thousands of years, so unless you had a very long time lapse photography study you would not see them change over centuries.

The Veil Nebula in Cygnus is actually a long loop of gas which is still expanding and the exited atoms therein (beacuse of the huge nuclear energy released) make them emit thei own light which is what we see and can these days photograph with sensitive detectors.

There are some time lapse photographs which do show movement particularly in the example of the Crab Nebula (M1) in Taurus (which exploded in 1054 AD) and in the Supernova 1987A which exploded on 24 February 1997. This is well studied and can be seen in the actual process of expansion (because it was so recent) I suggest you see the photos, taken at intervals of about 6 months, which has taught astronomers an awful lot about the process. (I think these are on the Hubble Site, if not then the ESO, ESA or Keck Telescope site shows them).

Even more interesting is that the remaining core of the massive star, if it exceeds about 3 solar masses will collapse into a black hole (but that is another story). In fact a supernova is ovedue to happen in our Galaxy, hope its soon - but not too close or it will kill us all very quickly with X-Rays, Gamma Rays etc.

Sorry to end on a rather shocking note.

Hope that's good enough for you.

Answer 2

The Veil Nebula is an old supernova remnant, several thousand years old. The graceful tracery is the result of multiple reflected shock waves interacting with the variable density of the interstellar medium.

The interstellar gas is unlike other materials you are used to, because it is highly compressable, and has a "equation of state" that causes it to compress even more easily once it is compressed just a little. So any shock wave (originally from the supernova) will result in a dense surface of material, and that dense surface will also cause a "reverse shock" that sends another shock wave back in the opposite direction. Since the original material was lumpy, this creates the delicate pattern of interwoven shocked surfaces. The interstellar medium only glows for a while after it is shocked, so there is a lot more material in those pictures that is does not show up because it is not currently undergoing a shock.

Answer 3

You're seeing the expulsion of gas & dust from a supernova.

And, yes the do move - The Crab Nebula, which exploded about 1000 years ago, shows how it's image has changed over the years - it's expanding and becoming more diffuse as time goes on. Probably in a million years or so, we'll see it much the same way we see the Veil nebula today.

Answer 4

The Veil is, like you say, the most graceful, ethereal and exquisite of all the nebula's.

While not an actual Supernova, this is pretty awesome to watch. Here is a link to a quick time movie of the expansion of the Light Echo surrounding V838 Mon. Since the star went into outburst in 2002, astronomers have been imaging it at regular intervals. This movie is made from each of those photos.
http://www.spacetelescope.org/videos/320px/heic0617a.mov
Some info.
The unusual variable star V838 Monocerotis (V838 Mon) continues to puzzle astronomers. This previously inconspicuous star underwent an outburst early in 2002, during which it temporarily increased in brightness to become 600,000 times more luminous than our Sun. Light from this sudden eruption is illuminating the interstellar dust surrounding the star, producing the most spectacular "light echo" in the history of astronomy.

Answer 5

The Veil Nebula is a supernova remnant--- the remains of an exploding star.

While the nebula is certainly expanding, it is so far away that no motion would ever be detectable in a human lifetime.

Answer 6

I have observed the Veil Nebula many times with my telescopes. It is even more exquisite seen through a telescope, as the tangled wisps are extremely faint yet well defined, especially with an OIII filter.

Answer 7

Yes the death of a star is a beautiful sight,, And yes they expand at rapid rates but are so far away that we would never detect it, Some of those nebulas are light years accross