APOD: Pillars of the Eagle Nebula in Infrared (2018 Jun 20)

[APOD Robot]

Pillars of the Eagle Nebula in Infrared

Explanation: Newborn stars are forming in the Eagle Nebula. Gravitationally contracting in pillars of dense gas and dust, the intense radiation of these newly-formed bright stars is causing surrounding material to boil away. This image, taken with the Hubble Space Telescope in near infrared light, allows the viewer to see through much of the thick dust that makes the pillars opaque in visible light. The giant structures are light years in length and dubbed informally the Pillars of Creation. Associated with the open star cluster M16, the Eagle Nebula lies about 6,500 light years away. The Eagle Nebula is an easy target for small telescopes in a nebula-rich part of the sky toward the split constellation Serpens Cauda (the tail of the snake).

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[Boomer12k]

Awesome to see through much of it...


:---[===] *

[De58te]

So if the infrared light is allowing us to see through the obscuring dense dust to see the hidden baby stars, what then are those dark brown and dark grey objects that still have a pillar shape? Are they actually dark matter behind the pillars?

[BobStein-VisiBone]

Infrared reveals...



...Eagle tastes like chicken.

[Chris Peterson]

So if the infrared light is allowing us to see through the obscuring dense dust to see the hidden baby stars, what then are those dark brown and dark grey objects that still have a pillar shape? Are they actually dark matter behind the pillars?

The pillars are made mostly of hydrogen gas, with a little bit of dust. The dust is what is optically dense, and limits how deeply we can see. At long wavelengths the dust is less attenuating, but by no means does it become transparent. It's still dust we see. Ordinary matter. Dark matter can never be seen using any sort of electromagnetic radiation. It is its lack of interaction with EM that makes it "dark".

[Roo]

They look like dementors.

[Sa Ji Tario]

I understand that the infrared image "lets see the stars through" the dust but said dust is still outlined in the image

[Sa Ji Tario]

In this image some will "see" a centaur with a large tail holding a shield with his right arm

[MarkBour]

Why is there such a tendency here for stars to be located

Capture.JPG (18.79 KiB) Viewed 10302 times

at the upper right tips of the clouds? (At about the 1 o'clock position in relation to them). There are multiple examples, but the most striking one of all, of course, is:

It seems as though a pressure wave came from that direction and shaped the pillars and encouraged the collapses that brought about star formation, but now that material is being stripped away.

In particular, regarding this excerpt, this looks like a set of 5 or more infant stars that have formed together in this pillar.





I also find this pattern in the lower right very interesting.

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[Ann]

Why is there such a tendency here for stars to be located at the upper right tips of the clouds? (At about the 1 o'clock position in relation to them). There are multiple examples, but the most striking one of all, of course, is:

It seems as though a pressure wave came from that direction and shaped the pillars and encouraged the collapses that brought about star formation, but now that material is being stripped away.

In particular, regarding this excerpt, this looks like a set of 5 or more infant stars that have formed together in this pillar.

Click to view full size image

The Cone Nebula, with three infant stars
at the tip. Photo: Hubble.

Click to view full size image

The Horsehead Nebula, with an infant star at top.
Image Credit: ESO/J. Emerson/VISTA. Acknowledgment:
Cambridge Astronomical Survey Unit
Credit for Hubble Data: HLA, Hubble Heritage Team (STScI/AURA)
Composite Assembly and Processing: Robert Gendler

Like you said, stars do seem to form at the top of these pillars. I guess your explanation is as good as any: The fierce stellar wind that carved out the pillar in the first place also compressed the tip of it, encouraging star formation. My impression is that the stars that form this way are typically relatively low-mass ones.

Ann

[Catalina]

Is it possible that infant stars are mostly "visible" at the tips of the pillars where the dust has been blown away completely and that there are quite possibly many more infant stars obscured from view by the bulk of the stellar dust still "downwind" of the tips?

[MarkBour]

Is it possible that infant stars are mostly "visible" at the tips of the pillars where the dust has been blown away completely and that there are quite possibly many more infant stars obscured from view by the bulk of the stellar dust still "downwind" of the tips?

That seems reasonable to me ... I wonder if even more penetrating IR observations might reveal whether that is the case or not.
If the more deeply embedded stars are radiating, I would suspect some sign of that would be detectable.

[Ann]

Is it possible that infant stars are mostly "visible" at the tips of the pillars where the dust has been blown away completely and that there are quite possibly many more infant stars obscured from view by the bulk of the stellar dust still "downwind" of the tips?

That seems reasonable to me ... I wonder if even more penetrating IR observations might reveal whether that is the case or not.
If the more deeply embedded stars are radiating, I would suspect some sign of that would be detectable.

Click to view full size image

The Elephant Trunk Nebula with embedded infant stars.
Photo: Lóránd Fényes

I doubt it. It seems to me that even infrared photography show the newborn stars to be located preferentially at the tip of gaseous pillars.

Take a look at the picture at right of the Elephant Trunk Nebula in IC 1396. The embedded star near the tip of this pillar is given away by the orange color of it. Dust reddening causes the orange color.

Interestingly, a number of moderately bright stars seem to "adorn the outline" of the Elephant Trunk Nebula. It is certainly possible that these stars, too, "hatched" inside the Elephant Trunk Nebula, near the interface between the nebula and its surroundings. This great picture shows more clearly what is going on inside the Elephant Trunk.

Click to view full size image

The Dark Tower in Scorpius. Photo: Don Goldman.

A fascinating example of a pillar is the Dark Tower in Scorpius, which is known as a cometary globule. At the very tip of it, stars are clearly forming. Indeed, they seem to form preferentially outside the darkest outline of the Dark Tower. But interestingly, this cometary globule (or pillar) is also "wearing a necklace of blue stars", which have probably hatched from their nebula relatively recently. Since then, however, the Dark Tower has shrunk.

Click to view full size image

Pillars in the Carina Nebula.
NASA, ESA, M. Livio and the Hubble 20th Anniversary Team

A truly fascinating example of pillars hatching stars at their tips can be seen in this picture of objects in the Carina Nebula. These two crazily hatching pillars have been called "Eagle Nebula on steroids".

Ann

[geckzilla]

It makes total sense that as the pillars erode away, the densest parts form tips and there are also stars in those denser parts. A more tenuous nebula would be blown apart more easily and have a lower chance at having enough mass to form a star. I figure it's not so much that the stars like to hang out and form at the tips, but rather that the tips are the most dense, most time-consuming to erode, and more likely to be forming stars.

There are a lot of examples in WISE and Spitzer data (much deeper into infrared wavelengths than Hubble) of stars forming along seams and not just at the tips. The wavelengths Hubble can capture probably are not penetrating nearly as much dust, so it is probably also correct that where the tips have been worn down, it is easier for Hubble to glimpse.

[MarkBour]

Thanks, Ann and Geck for the beautiful examples and persuasive reasoning.

"The Eagle Nebula on steroids" ?
How about "the Eagle Nebula on Clomiphene" ?