Do nebulae look different over months and years and centuries?

Question

I was reading an article that said the "Pillars of Creation" may have already collapsed and that what we see is a ghost image and will be so for about another 1000 years.

My question is if (obviously hypothetically) we took a picture of these pillars everyday for the next one-thousand years, would be able to see minute changes in its form? Do things like this (I don't know what to call it - gas clouds/dust?) move at a rate that is perceptible to the human eye/human time-scale, or do they move so slow that we would be able to see such changes?

Would all of the nebulae we know look different every time we photographed them because they are expanding/moving/morphing (kind of like clouds do if you stare at them long enough), or do they move so slowly (compared to human perception of time) that we don't notice?

Answer 1

since they are moving, yes, if we waited long enuf, we would see changes.

i have heard this argued for m1, the crab nebula. in messier's time it was significantly younger than it is now, and it may have been smaller and brighter, a lot more obvious in teh sky.

Answer 2

For the most part, their appearance would not change significantly over months and years. However, there are some nebulae that can change their appearance rapidly such as NGC-2261 in Monoceros and NGC's 6726, 6727 and 6729 in Corona Australis. All of these nebulae are reflection nebulae surrounding stars that had just formed, and clouds of dust orbiting the stars cast shadows on them that can change from night to night, week to week. All other nebulae do not do this, but over centuries and millenia, they will expand, change shape or evaporate from the action of radiation from very hot stars in or near them. Or they can expand due to the fact they originated in a supernova explosion. The Crab Nebula has in photographs taken over a period of decades shown a definite expansion. At a distance of some 8,000 light years, it is indeed possible the "Pillars of Creation" in the heart of M-16 no longer exist right now in reality. Even if they still do, a good bit of them is probably already eroded way by the birth and growth of young stars in the Eagle Nebula. Massive stars from birth to death live their lives in the fast lane, evolving quickly and dying off even more rapidly. The intense UV radiation they give off and the shock waves from their exploding as supernovae will render those pillars a thing of the past in a blink of an eye, astronomically speaking.

Answer 3

Over a few moths you're not going to see many cahnges but over the course of a few hundred years, yes!

Answer 4

Great question!

We are of course limited by the length of time deep sky photography has been possible, but even within those limits (about 120 years), numerous changes in nebulae have been observed. The Crab Nebula is a case in point. We know when this started (supernova in 1054 AD), and it was one of the first deep sky objects imaged in the 19th century. As Tina notes, it was definitely smaller and brighter when Messier first observed it in 1758 (the 250th anniversary of its discovery is on September 12). In fact, assuming linear expansion, the Crab as 26% smaller in diameter then than it is today.

Answer 5

Teensy -

They certainly change, but the time scale is - in virtually all cases - on the order of centuries, not months or years. And even then the changes would be pretty imperceptible based on visual observations alone. Supernovae change quickly. Just about everything else, including the nebular aftereffects of supernovae, take a very long time.