APOD: Ou4: A Giant Squid in a Flying Bat (2020 Oct 07)

[APOD Robot]

Ou4: A Giant Squid in a Flying Bat

Explanation: A very faint but very large squid-like nebula is visible in planet Earth's sky -- but inside a still larger bat. The Giant Squid Nebula cataloged as Ou4, and Sh2-129 also known as the Flying Bat Nebula, are both caught in this cosmic scene toward the royal royal constellation Cepheus. Composed with 55 hours of narrowband image data, the telescopic field of view is 3 degrees or 6 Full Moons across. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's alluring bipolar shape is distinguished here by the telltale blue-green emission from doubly ionized oxygen atoms. Though apparently completely surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, a more recent investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, Ou4 would represent a spectacular outflow driven by HR8119, a triple system of hot, massive stars seen near the center of the nebula. The truly giant Squid Nebula would physically be nearly 50 light-years across.

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[rj rl]

I'm confused. The smaller Ou4 does look like both a squid and a bat, the bigger Sh2-129 certainly doesn't resemble a bat whichever way I look at it.

[Ann]

The fact that HR 8119 is a massive triple star likely has something to do with that enormous collimated outflow, say I, the expert...

The illustration (by NASA and C. Reed) does not show HR 8119, but it seems to me, nevertheless, that a pair of very hot and massive stars orbiting one another might lead to some really nasty hiccups and upheavals.

Why has the distance to HR 8119 not been determined yet? Where is Gaia?

Ann

[XgeoX]

For what it’s worth I looked up HR8119 and Starry Night had it at 890 pc while a 2014 research paper at ...
https://www.researchgate.net/publicatio ... utflow_Ou4
has an “improved determination” at 712 pc.

Eric

[orin stepanek]

A Blue squid yet!

[johnnydeep]

I'm confused. The smaller Ou4 does look like both a squid and a bat, the bigger Sh2-129 certainly doesn't resemble a bat whichever way I look at it.

Yeah, I can accept a "squid" (though it has no tentacles), but I see no "bat" anywhere (not even as an alternate interpretation of the "squid"). Sometimes astronomers seem to try way too hard to make up memorable names

[Ann]

I'm confused. The smaller Ou4 does look like both a squid and a bat, the bigger Sh2-129 certainly doesn't resemble a bat whichever way I look at it.

Yeah, I can accept a "squid" (though it has no tentacles), but I see no "bat" anywhere (not even as an alternate interpretation of the "squid"). Sometimes astronomers seem to try way too hard to make up memorable names

Well, since there are no squids or bats in space (certainly not free-floating light-year-long specimens), we should perhaps not expect to see any such beasts in the cosmic wilderness.

Ann

[ptahhotep]

I'm confused. The smaller Ou4 does look like both a squid and a bat, the bigger Sh2-129 certainly doesn't resemble a bat whichever way I look at it.

Yeah, I can accept a "squid" (though it has no tentacles), but I see no "bat" anywhere (not even as an alternate interpretation of the "squid"). Sometimes astronomers seem to try way too hard to make up memorable names

I can see the blue squid. I presume the red is the bat but we can only see part of it and would need a wider view to appreciate its bat-like qualities.

[Guest20]

I do not see the bat. This happens for so many named images.
Does anyone know of a website that shows an outline of these shapes? Similar to images that show a constellation traced amongst its stars.

[neufer]

Click to play embedded YouTube video.

The smaller Ou4 does look like both a squid and a bat, the bigger Sh2-129 certainly doesn't resemble a bat whichever way I look at it.

Yeah, I can accept a "squid" (though it has no tentacles), but I see no "bat" anywhere (not even as an alternate interpretation of the "squid").

I can see the blue squid. I presume the red is the bat but we can only see part of it and would need a wider view to appreciate its bat-like qualities.

The red bat is almost upside down having just captured a blue squid/moth.

[johnnydeep]

Click to play embedded YouTube video.

Yeah, I can accept a "squid" (though it has no tentacles), but I see no "bat" anywhere (not even as an alternate interpretation of the "squid").

I can see the blue squid. I presume the red is the bat but we can only see part of it and would need a wider view to appreciate its bat-like qualities.

The red bat is almost upside down having just captured a blue squid/moth.

Now, here's a respectable "bat nebula", from https://apod.nasa.gov/apod/ap191125.html, though I think it looks more like a Great Horned Owl:

NGC 6995 - The Bat Nebula

---

And I suppose this must be the bat nebula people see in SH2-129 (from http://www.astrofoto.ca/stuartheggie/cc ... a)_big.jpg): - and we even get two bright "eyes"! - but I guess because of the different filters being used, we don't see the "squid nebula"?:

Sh2-129 - "The Bat Nebula"

[starsurfer]

You can see a list of all of Nicolas Outters discoveries here.

[alcor]

Talking about bats. Don't go too near the Bat Nebula, with its massive stars system. Or you have as Kathryn Janeway in a Star Trek Voyager episode to "batten down the hatches", when they come too close to a double neutron star system (https://www.youtube.com/watch?v=CeHtOxJMgDk).

[johnnydeep]

Talking about bats. Don't go too near the Bat Nebula, with its massive stars system. Or you have as Kathryn Janeway in a Star Trek Voyager episode to "batten down the hatches", when they come too close to a double neutron star system (https://www.youtube.com/watch?v=CeHtOxJMgDk).

Ha! Good ol' Janeway. And "a class 9 neutronic wavefront" - gotta love the liberties sci-fi TV takes with science!

[MarkBour]

The shape of the nebula is so complex, I find it hard to imagine its history and development. An interesting development at the left of the structure, it appears that the bright orange star is pushing it back. I would guess that's a recent development. For imagery, it could be a bright moth that the bat has just captured in its mouth (I just watched that great video that Art posted above).

[johnnydeep]

The shape of the nebula is so complex, I find it hard to imagine its history and development. An interesting development at the left of the structure, it appears that the bright orange star is pushing it back. I would guess that's a recent development. For imagery, it could be a bright moth that the bat has just captured in its mouth (I just watched that great video that Art posted above).

Yes, great observation!