Starship Asterisk*

Jim28625 wrote:Has anyone ever postulated on the size of the star that went supernova to create this amazing structure? It had to have been the largest star in our galaxy at the time. I wonder how long ago it exploded? I bet a simulated time lapsed sequence of it forming from the supernova to now would be an amazing treat. Absolutely incredible!

rascar wrote:What is meant by "re-assigned colors?
What is the process involved?

APOD Robot wrote:
The dust sculptures of the Eagle Nebula are evaporating.
...
The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust

flash wrote:What sense of the word "Evaporate" is meant here? In common use, evaporate is of course meant as transition of matter from liquid to gas. (Sublimation for transition from solid directly to gas.) I presume that the matter in the nebula that is "evaporating" is already more tenuous than what we commonly experience as the results of evaporation here on Earth. So if the nebula already consists of "gas and dust", to what does it evaporate?

Chris Peterson wrote:It is simply becoming even more tenuous. In this context, it means "dissipate".

flash wrote:

Chris Peterson wrote:It is simply becoming even more tenuous. In this context, it means "dissipate".

What I see in such images is a distinct boundary between the nebula's pillar "as in Pillars of Creation http://apod.nasa.gov/apod/ap100328.html" and the surrounding relatively empty space. I assume that the boundary is distinct due to the sharp change either in the density of the matter across the boundary or in the reflectivity (or luminosity) of that matter. Radiation (or solar wind) pushing the matter away (dissipating it) doesn't seem (to me, at least) a sufficient explanation for the distinct boundaries evident. In my experience, merely pushing dust around doesn't eliminate the dustiness: It merely moves the dust to somewhere else. Is there something else going on here?

flash wrote:In my experience, merely pushing dust around doesn't eliminate the dustiness: It merely moves the dust to somewhere else. Is there something else going on here?

NoelC wrote:I question whether you've ever pushed enough dust around that the large mass of it created mutual gravitational attraction. I don't think the stuff you observe in the air in your room can be extrapolated to this scale.

Clearly it occasionally squeezes itself together well enough to make stars and planets. Why is it hard to imagine that this is a phase of that?

http://www.universetoday.com/92705/the-eagle-nebula-as-youve-never-seen-it-before/#more-92705 wrote:
The Eagle Nebula as You’ve Never Seen it Before
by Nancy Atkinson on January 17, 2012

[b][color=#0000FF]M16 seen in several different wavelengths. Credits: far-infrared: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium; ESA/XMM-Newton/EPIC/XMM-Newton-SOC/Boulanger; optical: MPG/ESO; near-infrared/VLT/ISAAC/McCaughrean & Andersen/AIP/ESO[/color][/b]

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<<Here’s a stunning new look deep inside the iconic “Pillars of Creation.” As opposed to the famous Hubble Space Telescope image — which shows mainly the surface of the pillars of gas and dust — this composite image from ESA’s Herschel Space Observatory in far-infrared and XMM-Newton telescope in X-rays allows astronomers to peer inside the pillars and see more detail of the structures in this region. It shows how the hot young stars detected by the X-ray observations are carving out cavities, sculpting and interacting with the surrounding ultra-cool gas and dust.

But enjoy the view while you can. The sad part is that likely, this beautiful region has already been destroyed by a supernova 6,000 years ago. But because of the distance, we haven’t seen it happen yet.

The Eagle Nebula is 6,500 light-years away in the constellation of Serpens. It contains a young hot star cluster, NGC6611, which is visible with modest back-yard telescopes. This cluster is sculpting and illuminating the surrounding gas and dust, resulting in a huge hollowed-out cavity and pillars, each several light-years long.

The Hubble image hinted at new stars being born within the pillars, deep inside small clumps known as ‘evaporating gaseous globules’ or EGGs, but because of the obscuring dust, Hubble’s visible light picture was unable to see inside and prove that young stars were indeed forming.

The new image shows those hot young stars are responsible for carving the pillars. The new image also uses data from near-infrared images from the European Southern Observatory’s (ESO’s) Very Large Telescope at Paranal, Chile, and visible-light data from its Max Planck Gesellschaft 2.2m diameter telescope at La Silla, Chile. Earlier mid-infrared images from ESA’s Infrared Space Observatory and NASA’s Spitzer, and the new XMM-Newton data, have led astronomers to suspect that one of the massive, hot stars in NGC6611 may have exploded in a supernova 6,000 years ago, emitting a shockwave that destroyed the pillars. But we won’t see the destruction for several hundred years yet.>>