APOD: NGC 1893 and the Tadpoles of IC 410 (2024 Feb 02)

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APOD: NGC 1893 and the Tadpoles of IC 410 (2024 Feb 02)

Post by APOD Robot » Fri Feb 02, 2024 5:07 am

Image NGC 1893 and the Tadpoles of IC 410

Explanation: This cosmic view shows off an otherwise faint emission nebula IC 410, captured under clear Netherlands skies with telescope and narrowband filters. Above and right of center you can spot two remarkable inhabitants of the interstellar pond of gas and dust, known as the tadpoles of IC 410. Partly obscured by foreground dust, the nebula itself surrounds NGC 1893, a young galactic cluster of stars. Formed in the interstellar cloud a mere 4 million years ago, the intensely hot, bright cluster stars energize the glowing gas. Globules composed of denser cooler gas and dust, the tadpoles are around 10 light-years long and are likely sites of ongoing star formation. Sculpted by stellar winds and radiation their heads are outlined by bright ridges of ionized gas while their tails trail away from the cluster's central young stars. IC 410 and embedded NGC 1893 lie some 10,000 light-years away, toward the nebula-rich constellation Auriga.

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johnnydeep
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Re: APOD: NGC 1893 and the Tadpoles of IC 410 (2024 Feb 02)

Post by johnnydeep » Fri Feb 02, 2024 3:30 pm

Are we perhaps witnessing the maculate empyrean misconception of the Star Child? (I just couldn't ignore the obvious sperm and egg pareidolic eidolon going on here. 😉)
Last edited by johnnydeep on Fri Feb 02, 2024 7:02 pm, edited 1 time in total.
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Ann
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Re: APOD: NGC 1893 and the Tadpoles of IC 410 (2024 Feb 02)

Post by Ann » Fri Feb 02, 2024 6:52 pm

Why do things disagree with one another? There may be nothing wrong with either of them on their own, but together, they just don't mesh. Imagine you have bought a new brand a coffee for your friends and everyone likes it except one person - to him or her, the coffee appears to make this kind of face:

Depresso.png

One of your friends didn't like the coffee because of his or her personal taste. Don't sweat it. There was nothing wrong with the coffee in itself, and people have different tastes.

I'm like that picky friend, in that today's APOD doesn't appeal very much to me because of my strong ideas about color. :| That's me. Don't sweat it.¯\_(ツ)_/¯

Anyway. Normally I always post a picture of today's APOD, but not today, because the APOD is too large. So I'll post another picture of the Tadpole Nebula:


The picture by Christopher Gomez and Ruben Barbosa has a tighter field of view than the APOD, and their palette is not the same, either. But you can see the tadpoles very well, and the young cluster, NGC 1893, is quite visible as it is peeking out behind a dust cloud.

Very little seems to be known about the central cluster of the Tadpole Nebula, but I'm going to guess that it is reasonably similar to the cluster inside the Flame Nebula:


The Flame Nebula cluster is completely hidden from us at optical wavelengths, but it is reasonably close to us at ~1,500 light-years. Cluster NGC 1893 can be detected at optical wavelengths, but it is some ~8 times farther away from us than the Flame Nebula Cluster.

And the stars inside the Tadpole Nebula cluster are energetic. How do we know? It's because the central part of the Tadpole often looks "all blue" in narrowband images due to OIII emission. The presence of so much OIII emission is itself a sign of high levels of ionization usually caused by hot stars:


In visual light, IC 405 is bluer than the Tadpole Nebula:

390_1452_bb8de17a_ic405_410_ederL[1].jpg
The Tadpole Nebula (left) and the Flaming Star Nebula (right). Credit: Éder Iván

The reason why the Flaming Star Nebula is partly bluish at visible wavelengths is that the entire Flaming Star Nebula has been lit up by a single star, runaway star AE Aurigae. AE Aurigae just blundered into this cloud of gas and dust during its headlong flight through space, and its ultraviolet light has ionized the hydrogen of this gas cloud and made it glow red, while the blue light of the star has lit up dust in the nebula.

No blue light can really be seen from the Tadpole Nebula, which is lit up not by one star, but by a whole cluster. Fun fact, though: The Tadpole Nebula is almost ten times farther away than the Flaming Star Nebula! Therefore the Tadpole Nebula is much more reddened by dust, but you can also imagine how much bigger it really is than the Flaming Star Nebula.

What about the Tadpoles, though? Well, they are simply pillars of exactly the same kind as the Pillars of Creation in the Eagle Nebula. These structures form as the nebula that birthed the stars is being eaten away by the ultraviolet light and harsh stellar winds from the hottest stars that it just gave birth to. The thickest parts of the nebulas form "comet heads" which shield the "downwind areas" behind them, thus forming pillars.


I must return for a moment to Éder Iván's picture of the Tadpole and the Flaming Star nebulas. I can't resist:

IQ Aurigae Flame and Tadpole nebulas Ivan Eder.png

Ladies and gentlemen, meet IQ Aurigae! The hottest and bluest of all stars that have been classified as spectral class A. It has been classified as spectral class A because its helium lines are weak, but its color is characteristic of spectral class B4, and its temperature is 17,000 K, about double that of most A-type stars.


Yes, yes, I know, you were all so excited to learn about IQ Aurigae!! Don't you thank me all at once! :mrgreen:

But before I go, I must talk about my absolutely favorite thing about today's APOD. I would so much like to post the APOD here, but I can't, because it is too big, and I have used up my three attachments. But look at the APOD yourselves. Look at what is written in the lower right corner: Carpe Noctem.

Isn't it lovely? We all know about Carpe Diem: Seize the day, grab hold of your day, don't let it slip through your fingers. Carpe Noctem means, obviously, seize the night. See the beauty of the night and show it to other people.

I love that. Thank you, Sander de Jong!


[youtube]https://www.youtube.com/watch?app=desktop&v=pV58YptFTK0[/youtube]


Ann
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Last edited by Ann on Fri Feb 02, 2024 7:38 pm, edited 1 time in total.
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Chris Peterson
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Re: APOD: NGC 1893 and the Tadpoles of IC 410 (2024 Feb 02)

Post by Chris Peterson » Fri Feb 02, 2024 7:06 pm

Ann wrote: Fri Feb 02, 2024 6:52 pm Very little seems to be known about the central cluster of the Tadpole Nebula, but I'm going to guess that it is reasonably similar to the cluster inside the Flame Nebula...
Here you go, Ann. My image of the Tadpoles... it's narrowband, so not necessarily your favorite, but perhaps that's made up for by a LOT of lovely blue [O III]!

And by coincidence, I was imaging IC 405 just a couple of nights ago. Such a weird looking thing with all that red H mixed up with strong blue reflection nebulosity, all driven by a star that's just passing through. (And BTW, this is not the Flame Nebula. That name is generally applied to NGC 2024, over in Orion next to the Horsehead. IC 405 is commonly called the Flaming Star Nebula.)
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IC410_sho.jpg
IC405_hrgb.jpg
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Ann
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Re: APOD: NGC 1893 and the Tadpoles of IC 410 (2024 Feb 02)

Post by Ann » Fri Feb 02, 2024 7:33 pm

Chris Peterson wrote: Fri Feb 02, 2024 7:06 pm
Ann wrote: Fri Feb 02, 2024 6:52 pm Very little seems to be known about the central cluster of the Tadpole Nebula, but I'm going to guess that it is reasonably similar to the cluster inside the Flame Nebula...
Here you go, Ann. My image of the Tadpoles... it's narrowband, so not necessarily your favorite, but perhaps that's made up for by a LOT of lovely blue [O III]!

And by coincidence, I was imaging IC 405 just a couple of nights ago. Such a weird looking thing with all that red H mixed up with strong blue reflection nebulosity, all driven by a star that's just passing through. (And BTW, this is not the Flame Nebula. That name is generally applied to NGC 2024, over in Orion next to the Horsehead. IC 405 is commonly called the Flaming Star Nebula.)
_
IC410_sho.jpg
IC405_hrgb.jpg
Stupid me (about the Flaming Star Nebula)!

And I like your Tadpole Nebula, Chris! And I just love your portrait of the Flaming Star Nebula! ❤️💗💙

Okay, now I'll edit my stupid post...

Ann
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