APOD: Inside the Eagle Nebula (2014 Feb 16)

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APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by APOD Robot » Sun Feb 16, 2014 5:05 am

Image Inside the Eagle Nebula

Explanation: From afar, the whole thing looks like an Eagle. A closer look at the Eagle Nebula, however, shows the bright region is actually a window into the center of a larger dark shell of dust. Through this window, a brightly-lit workshop appears where a whole open cluster of stars is being formed. In this cavity tall pillars and round globules of dark dust and cold molecular gas remain where stars are still forming. Already visible are several young bright blue stars whose light and winds are burning away and pushing back the remaining filaments and walls of gas and dust. The Eagle emission nebula, tagged M16, lies about 6500 light years away, spans about 20 light-years, and is visible with binoculars toward the constellation of the Serpent (Serpens). This picture combines three specific emitted colors and was taken with the 0.9-meter telescope on Kitt Peak, Arizona, USA.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by geckzilla » Sun Feb 16, 2014 6:02 am

It's very easy to see the eagle's wings and its hooked beak in this image. For a long time I had no idea why the Eagle Nebula was called that because I was only familiar with Hubble's Pillars of Creation. Outside of astronomy circles few people look at any pictures other than famous images from Hubble or our darling space probes like Voyagers and Cassini. It's funny how you can miss the bigger picture by only looking at big pictures.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Boomer12k » Sun Feb 16, 2014 9:31 am

Awesome Eagle Nebula Pic!!!

Geckzilla...I too was only thinking of "The Pillars of Creation" AS THE EAGLE NEBULA....my limited knowledge at the time...but it is the over all BIG SHAPE of the DUST I think.

The Eagle....watches over her BROOD....new stars....AWESOME!!!!!!!!!

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Tszabeau » Sun Feb 16, 2014 2:05 pm

How do the pillars form? Are they pulled out by the stars births? Do the pillars push the newborn stars or do the stars string the pillars out like breadcrumbs as the accelerate? What starts the motion of a newborn star? Does the nebula exert positive or negative momentum to it's child stars, relative to outsider stars which just happen to pass through it?

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Chris Peterson » Sun Feb 16, 2014 3:06 pm

geckzilla wrote:It's very easy to see the eagle's wings and its hooked beak in this image. For a long time I had no idea why the Eagle Nebula was called that because I was only familiar with Hubble's Pillars of Creation.
But what you're seeing isn't really the Eagle nebula, which is local to the Pillars and has no beak, just a body, wings, and talons.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Anthony Barreiro » Sun Feb 16, 2014 3:25 pm

geckzilla wrote:It's very easy to see the eagle's wings and its hooked beak in this image. For a long time I had no idea why the Eagle Nebula was called that because I was only familiar with Hubble's Pillars of Creation. Outside of astronomy circles few people look at any pictures other than famous images from Hubble or our darling space probes like Voyagers and Cassini. It's funny how you can miss the bigger picture by only looking at big pictures.
There is a unique magic to looking at things in the sky through a small telescope or even a decent pair of binoculars. You see less detail and color than you see through images, but there is an immediacy that is lost through image processing. You learn where things are in the sky, how they move through the sky with Earth's rotation, and what things are visible during different season as Earth's night side faces different directions from the Sun. You get a sense of where things are in our galaxy, and the directions to other galaxies relative to the plane of our galaxy. Also, if you observe different objects with the same equipment you can make direct comparisons. The Orion nebula is very bright and distinctly greenish. The Andromeda galaxy is huge and bright. M16 has outstretched wings and a head with a curved beak. Etc.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Case » Sun Feb 16, 2014 3:26 pm

Image
The Eagle Nebula is never very high in the sky in the northern hemisphere. Best viewed in late June, it maxes out at 44° alt. at Kitt Peak and only 29° in Lausanne, where the discoverer lived and worked.

Lots of telescopes won't go below 30°, and if that is the limit for the WIYN 0.9m, that would give an observing window of up to 5 hours in the best conditions. Probably much less.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Cousin Ricky » Sun Feb 16, 2014 4:07 pm

Tszabeau wrote:How do the pillars form? Are they pulled out by the stars births? Do the pillars push the newborn stars or do the stars string the pillars out like breadcrumbs as the accelerate? What starts the motion of a newborn star? Does the nebula exert positive or negative momentum to it's child stars, relative to outsider stars which just happen to pass through it?
They are not extruded or built up like clay sculptures; they are chiseled like marble. Intense radiation from the O- and B-stars in the center of the nebula is constantly eroding the dust cloud, but there are denser parts of the cloud which resist erosion. It’s similar to the way buttes form on Earth. These denser parts also shield the parts of the cloud behind them, which is what causes the pillars. The pillars are essentially the “umbras” of the OB-stars.

New stars form inside the pillars because inside the pillars is cold enough for proto-stars to collapse. As the dust cloud is eroded by existing OB-stars, the new stars become exposed.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Cousin Ricky » Sun Feb 16, 2014 4:15 pm

Is M16 the Eagle Nebula? It was my understanding that the Eagle Nebula is IC 4703, and M16/NGC 6611 is the open cluster within the nebula.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Anthony Barreiro » Sun Feb 16, 2014 5:04 pm

Cousin Ricky wrote:
Tszabeau wrote:How do the pillars form? Are they pulled out by the stars births? Do the pillars push the newborn stars or do the stars string the pillars out like breadcrumbs as the accelerate? What starts the motion of a newborn star? Does the nebula exert positive or negative momentum to it's child stars, relative to outsider stars which just happen to pass through it?
They are not extruded or built up like clay sculptures; they are chiseled like marble. Intense radiation from the O- and B-stars in the center of the nebula is constantly eroding the dust cloud, but there are denser parts of the cloud which resist erosion. It’s similar to the way buttes form on Earth. These denser parts also shield the parts of the cloud behind them, which is what causes the pillars. The pillars are essentially the “umbras” of the OB-stars.

New stars form inside the pillars because inside the pillars is cold enough for proto-stars to collapse. As the dust cloud is eroded by existing OB-stars, the new stars become exposed.
This is the clearest, most vivid explanation I've heard. Thanks. "Chiseled like marble," like buttes. I'm going to steal those lines.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by geckzilla » Sun Feb 16, 2014 5:13 pm

Chris Peterson wrote:
geckzilla wrote:It's very easy to see the eagle's wings and its hooked beak in this image. For a long time I had no idea why the Eagle Nebula was called that because I was only familiar with Hubble's Pillars of Creation.
But what you're seeing isn't really the Eagle nebula, which is local to the Pillars and has no beak, just a body, wings, and talons.
Hmm, I'm afraid I don't follow you on this.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by jsanchezjr » Sun Feb 16, 2014 5:41 pm

6,500 light years away... Well, this is not to much away like others celestial objects. The todays famous supernova in the cigar galaxy is 12 millions light years away. And others galaxys is even more away. That distance blow the mind of any person.

Btw, a few days ago I saw the movie 'Ender's Game' and for the first time, at least for me, in science fiction movies I could notice well applied the true concept of artificial gravity. Is well know that in space the gravity is a problem for stay upright on a space ship because, well, there is no gravity. But one way to create artificial gravity is using centrifugal force. Put yourself in a place that is spinning at a necessary speed and the centrifugal force will create the necessary force to keep you in place. The movie applies that concept very accurate, in several scene is show that part of the space station is spinning to create the centrifugal force. I had to replay the scene several time because I want to be sure and yes, the concept is there. I don't think that others movies show that concept to create gravity, at least I have not seen any

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by rstevenson » Sun Feb 16, 2014 6:01 pm

jsanchezjr wrote:... But one way to create artificial gravity is using centrifugal force. ... I don't think that others movies show that concept to create gravity, at least I have not seen any
2001: A Space Odyssey, the 1968 movie by Stanley Kubrick, clearly shows a spinning space station with people walking along the curving "floor" of the outer rim, as well as other applications of the same technology. There have been others, but that's probably the most famous.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by eltodesukane » Sun Feb 16, 2014 6:02 pm


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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Chris Peterson » Sun Feb 16, 2014 6:57 pm

geckzilla wrote:
Chris Peterson wrote:
geckzilla wrote:It's very easy to see the eagle's wings and its hooked beak in this image. For a long time I had no idea why the Eagle Nebula was called that because I was only familiar with Hubble's Pillars of Creation.
But what you're seeing isn't really the Eagle nebula, which is local to the Pillars and has no beak, just a body, wings, and talons.
Hmm, I'm afraid I don't follow you on this.
Here is how M16 looks through a telescope (which is the view by which its name "eagle" came about):
M16.jpg
And here's the eagle that is very visible through that telescope:
M16_eagle.jpg
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by TheStarDog » Sun Feb 16, 2014 7:13 pm

Just a point of interest, the left pillar inside the Eagle Nebula, I believe, also looks like an eagle sitting atop a perch with its head turned toward us. Has anyone ever mentioned this?

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by FloridaMike » Sun Feb 16, 2014 9:02 pm

I just pulled up the comments on the APOD Facebook page for the first time today. I had to immediately come here to say thank you to everyone who contributes.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Anthony Barreiro » Sun Feb 16, 2014 9:31 pm

Perhaps we should ask this woman what she sees when she looks at M16.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by geckzilla » Sun Feb 16, 2014 9:38 pm

FloridaMike wrote:I just pulled up the comments on the APOD Facebook page for the first time today. I had to immediately come here to say thank you to everyone who contributes.
Wow! Amazing! The Universe?!

Chris Peterson wrote:And here's the eagle that is very visible through that telescope:
[pictures]
Oooh, so that's how you are seeing the eagle. Here's what I see now. The top is how I originally interpreted the "eagle" of the eagle nebula. Below is how I understand you see it.
eaglespotting.jpg
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Anthony Barreiro » Sun Feb 16, 2014 10:11 pm

Sorry I'm not able to draw, but the whole darn nebula is is the eagle. The eagle's head is in the upper right, with the beak on the lower right side of the head. The wings are the large bright areas that extend from upper left to lower right.

Shall we also share our interpretations of Rorschach inkblots?
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by geckzilla » Sun Feb 16, 2014 11:18 pm

Like this, Anthony?
eagle3.jpg
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Chris Peterson » Sun Feb 16, 2014 11:26 pm

geckzilla wrote:Oooh, so that's how you are seeing the eagle. Here's what I see now. The top is how I originally interpreted the "eagle" of the eagle nebula. Below is how I understand you see it.
Of course, people are free to see it anyway they want. But there's actually a "real" way, which is how I drew it (and as you drew it below). I've seen that drawn in many old amateur astronomy references. The reason is simply that through a telescope, the pillars region is the only thing that has significant contrast. It's really the only obvious visual structure in M16, which otherwise just looks like a vague glow.

With modern imaging, of course, there's so much detail available that our native pareidolia takes over. But it's sometimes worthwhile to keep in mind the historical basis of some astronomical names.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by geckzilla » Sun Feb 16, 2014 11:40 pm

Yeah, I see that what clearly looks like a hooked beak to me now wouldn't have been obvious when the nebula earned its namesake and therefore the low contrast wouldn't likely contribute to any envisioned eagle shapes.
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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Nitpicker » Mon Feb 17, 2014 3:38 am

I am generally hopeless at spotting shapes in clouds (in the sky or deep space).

I had never been able to discern an eagle in this nebula until now. I do now see (vaguely) the smaller eagle in the pillars.

But this talk of which is the "real" eagle is not dissimilar to arguments over the "correct" way to join the dots to form asterisms within the official constellation boundaries. It is surprisingly common to see significantly different interpretations of asterisms, even just within western sky folklore.

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Re: APOD: Inside the Eagle Nebula (2014 Feb 16)

Post by Chris Peterson » Mon Feb 17, 2014 4:09 am

Nitpicker wrote:I am generally hopeless at spotting shapes in clouds (in the sky or deep space).

I had never been able to discern an eagle in this nebula until now. I do now see (vaguely) the smaller eagle in the pillars.

But this talk of which is the "real" eagle is not dissimilar to arguments over the "correct" way to join the dots to form asterisms within the official constellation boundaries. It is surprisingly common to see significantly different interpretations of asterisms, even just within western sky folklore.
Yes, but many of the bright named nebulas have been seen unambiguously for many decades. It's not so much a question of right or real, just recognizing where these names came from, and realizing that visually, the number of ways they're seen is much smaller. What people see may differ (e.g. a swan or an omega in M17), but how those things are seen doesn't typically change. Until we consider deep images, that is.
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