Starship Asterisk*

The Elephant's Trunk in IC 1396

Explanation: Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Of course, the cosmic elephant's trunk is over 20 light-years long. This composite was recorded through narrow band filters that transmit the light from ionized hydrogen, sulfur, and oxygen atoms in the region. The resulting image highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas. Such embedded, dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within the obscuring cosmic dust. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. This dramatic close-up covers a 2 degree wide field, about the size of 4 Full Moons.

<< Previous APOD

Discuss Any APOD

Next APOD >>

[/b]

It's fun what one's mind can picture in shapes formed by clouds; even in stellar clouds. The bright star even looks like it could be the elephants eye.

With apologies to all you elephant-lovers out there, all I see is simply wonderful abstract art !!

Sorry, I don't see an elephant's trunk. It's a woman walking forward out of the mist.

malcolm@maui.net wrote:Sorry, I don't see an elephant's trunk. It's a woman walking forward out of the mist.

An elegant, mysterious woman, at that.

Ah, the power of imagination.....

Just a quick reference and I was once again on the banks of the great grey-green, greasy Limpopo River.

Well done —

APOD Robot wrote: The Elephant's Trunk in IC 1396

Explanation: Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Of course, the cosmic elephant's trunk is over 20 light-years long. This composite was recorded through narrow band filters that transmit the light from ionized hydrogen, sulfur, and oxygen atoms in the region. The resulting image highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas. Such embedded, dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within the obscuring cosmic dust. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. This dramatic close-up covers a 2 degree wide field, about the size of 4 Full Moons.

The dense cosmic dust is hiding and forming new stars. So what happens to older mature stars that are moving through these dense areas of cosmic dust. These dust fields span 20 sometimes many more light years of distance. So surely a mature traveling star becomes smudged with this dark dust. Does this make common sense ?

Doug Ettinger
Pittsburgh, PA

dougettinger wrote:The dense cosmic dust is hiding and forming new stars. So what happens to older mature stars that are moving through these dense areas of cosmic dust. These dust fields span 20 sometimes many more light years of distance. So surely a mature traveling star becomes smudged with this dark dust. Does this make common sense ?

Even the thickest dust regions still qualify as hard vacuums. A star moving through will most likely simply blow the tenuous wisps away as it travels. I doubt the dust has any detectable impact on the star at all.

Chris Peterson wrote:

dougettinger wrote:
The dense cosmic dust is hiding and forming new stars. So what happens to older mature stars that are moving through these dense areas of cosmic dust. These dust fields span 20 sometimes many more light years of distance. So surely a mature traveling star becomes smudged with this dark dust. Does this make common sense ?

Even the thickest dust regions still qualify as hard vacuums. A star moving through will most likely simply blow the tenuous wisps away as it travels. I doubt the dust has any detectable impact on the star at all.

Or.....everything gets covered with soot

Chris Peterson wrote:

dougettinger wrote:The dense cosmic dust is hiding and forming new stars. So what happens to older mature stars that are moving through these dense areas of cosmic dust. These dust fields span 20 sometimes many more light years of distance. So surely a mature traveling star becomes smudged with this dark dust. Does this make common sense ?

Even the thickest dust regions still qualify as hard vacuums. A star moving through will most likely simply blow the tenuous wisps away as it travels. I doubt the dust has any detectable impact on the star at all.

And yet these "thickest dust regions or hard vacuums" can form "pillars of creation" and produce stars and planets. I sense some weird dichotomy here. IMC's can make stars and planets but do not affect existing stars and planets if they are moving through the same neighborhood.

Doug Ettinger
Pittsburgh, PA

dougettinger wrote:

Chris Peterson wrote:

dougettinger wrote:The dense cosmic dust is hiding and forming new stars. So what happens to older mature stars that are moving through these dense areas of cosmic dust. These dust fields span 20 sometimes many more light years of distance. So surely a mature traveling star becomes smudged with this dark dust. Does this make common sense ?

Even the thickest dust regions still qualify as hard vacuums. A star moving through will most likely simply blow the tenuous wisps away as it travels. I doubt the dust has any detectable impact on the star at all.

And yet these "thickest dust regions or hard vacuums" can form "pillars of creation" and produce stars and planets. I sense some weird dichotomy here. IMC's can make stars and planets but do not affect existing stars and planets if they are moving through the same neighborhood.

One Astronomical unit of Zodiacal light is quite noticeable:
http://antwrp.gsfc.nasa.gov/apod/ap100913.html
http://antwrp.gsfc.nasa.gov/apod/ap100320.html

Think how noticeable hundreds of thousands of AU of Zodiacal light would be.

Are you intimidated by being bathed in Zodiacal light? What if you were an astronaut?

dougettinger wrote:And yet these "thickest dust regions or hard vacuums" can form "pillars of creation" and produce stars and planets. I sense some weird dichotomy here. IMC's can make stars and planets but do not affect existing stars and planets if they are moving through the same neighborhood.

Think about the density of the Solar System. Even assuming that it started out with several times more mass than it currently has, it still was very, very low density. Only in the tiny volume at the center did the density become high enough to form a star. And as soon as that star began fusing, it blew away almost all the remaining dust and gas (with gas being the major component by many orders of magnitude). That is because the force of the stellar winds is many times greater than the force of gravity. And a protostar system is relatively dense compared with the other 99.999% of a dusty region like the Pillars of Creation, where there are no stars being born.

There is no "weird dichotomy".

Chris Peterson wrote:

dougettinger wrote:And yet these "thickest dust regions or hard vacuums" can form "pillars of creation" and produce stars and planets. I sense some weird dichotomy here. IMC's can make stars and planets but do not affect existing stars and planets if they are moving through the same neighborhood.

Think about the density of the Solar System. Even assuming that it started out with several times more mass than it currently has, it still was very, very low density. Only in the tiny volume at the center did the density become high enough to form a star. And as soon as that star began fusing, it blew away almost all the remaining dust and gas (with gas being the major component by many orders of magnitude). That is because the force of the stellar winds is many times greater than the force of gravity. And a protostar system is relatively dense compared with the other 99.999% of a dusty region like the Pillars of Creation, where there are no stars being born.

There is no "weird dichotomy".

Perhaps another way of stating the answer is that the spacing of star nurseries is similar to other normal mature star fields. And the dense dust to form proto-stars is already very concentrated.

I had a previous question about stellar winds and never received a clear answer. The stellar winds you speak about, I presume, are the winds from a newly formed star ? What is the percentage of the current solar wind force compared to the very young star just after it was born ?

Doug Ettinger
Pittsbrugh, PA

dougettinger wrote:Perhaps another way of stating the answer is that the spacing of star nurseries is similar to other normal mature star fields. And the dense dust to form proto-stars is already very concentrated.

Still, the area around a protostar- even the accretion disc around it- is very low density. The only zone that actually ends up with a density greater than a hard vacuum is the center of the protostar itself- a tiny volume compared with the entire system.

I had a previous question about stellar winds and never received a clear answer. The stellar winds you speak about, I presume, are the winds from a newly formed star ? What is the percentage of the current solar wind force compared to the very young star just after it was born ?

I don't know. Some protostars can go through a phase where they have strong winds, but I can't compare it to the Sun. But I wasn't limiting my discussion to the winds from protostars. The Sun, as it behaves now, is easily able to blow away any dust that might pass through our system. The solar wind from the Sun produces much higher forces on small particles than the Sun's gravity (and in the opposite direction, of course).