APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

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APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

Post by APOD Robot » Sat Oct 29, 2022 4:05 am

Image LDN 673: Dark Clouds in Aquila

Explanation: Part of a dark expanse that splits the crowded plane of our Milky Way galaxy, the Aquila Rift arcs through planet Earth's skies near bright star Altair. In eerie silhouette against the Milky Way's faint starlight, its dusty molecular clouds likely contain raw material to form hundreds of thousands of stars and astronomers search the dark clouds for telltale signs of star birth. This telescopic close-up looks toward the region at a fragmented Aquila dark cloud complex identified as LDN 673, stretching across a field of view slightly wider than the full moon. In the scene, visible indications of energetic outflows associated with young stars include the small red tinted nebulosity RNO 109 above and right of center, and Herbig-Haro object HH32 below. These dark clouds might look scary, but they're estimated to be some 600 light-years away. At that distance, this field of view spans about 7 light-years.

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Ann
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Re: APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

Post by Ann » Sat Oct 29, 2022 5:15 am

LDN673_1024[1].jpg
Location of stars in APOD 29 October 2022.png

This is where we are. The brightest blue star in the APOD is Omega-2 Aquila, a modest 6th magnitude star of spectral class A2V. It is located at a distance of some 250 light-years and is about as bright as Sirius.

Here's another bit of info as to where we are:


The star map only shows us Omega Aquila, ω (at upper right). But there are two omegas. Omega-2, the one we see in the APOD, is just left (east) of the Omega in the star map.

Ann
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Re: APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

Post by AVAO » Sat Oct 29, 2022 4:43 pm

APOD Robot wrote: Sat Oct 29, 2022 4:05 am ...In the scene, visible indications of energetic outflows associated with young stars include the small red tinted nebulosity RNO 109 above and right of center, and Herbig-Haro object HH32 below. ...
If you follow the link of HH32 there is written:

"HH 32 is an excellent example of a 'Herbig-Haro object', which is formed when young stars eject jets of material back into interstellar space...
Many young stars, like the central object in HH 32, are surrounded by disks of gas and dust that form as additional material is attracted gravitationally from the surrounding nebula."
(https://esahubble.org/images/opo9935a)

I like this HH object, but unfortunately I can't see any typical jets or discs of gas and dust here...
but yes two bow shocks can be seen...

Image
jac berne (flickr)

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Ann
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Re: APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

Post by Ann » Sat Oct 29, 2022 5:02 pm

AVAO wrote: Sat Oct 29, 2022 4:43 pm
APOD Robot wrote: Sat Oct 29, 2022 4:05 am ...In the scene, visible indications of energetic outflows associated with young stars include the small red tinted nebulosity RNO 109 above and right of center, and Herbig-Haro object HH32 below. ...
If you follow the link of HH32 there is written:

"HH 32 is an excellent example of a 'Herbig-Haro object', which is formed when young stars eject jets of material back into interstellar space...
Many young stars, like the central object in HH 32, are surrounded by disks of gas and dust that form as additional material is attracted gravitationally from the surrounding nebula."
(https://esahubble.org/images/opo9935a)

I like this HH object, but unfortunately I can't see any typical jets or discs of gas and dust here...

Image
jac berne (flickr)

Don't ask me about the disk of gas and dust, but the jets are here:



The jets look green and blue in this Hubble image - or rather, the green and blue stuff is hydrogen and sulfur that has been ionized by jets from HH32!

Of course, the true color of ionized hydrogen and sulfur is red. So, therefore, the red stuff in the image you posted is hydrogen and sulfur that has been ionized by jets!

Ann
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Re: APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

Post by AVAO » Sat Oct 29, 2022 5:10 pm

Ann wrote: Sat Oct 29, 2022 5:02 pm
AVAO wrote: Sat Oct 29, 2022 4:43 pm
APOD Robot wrote: Sat Oct 29, 2022 4:05 am ...In the scene, visible indications of energetic outflows associated with young stars include the small red tinted nebulosity RNO 109 above and right of center, and Herbig-Haro object HH32 below. ...
If you follow the link of HH32 there is written:

"HH 32 is an excellent example of a 'Herbig-Haro object', which is formed when young stars eject jets of material back into interstellar space...
Many young stars, like the central object in HH 32, are surrounded by disks of gas and dust that form as additional material is attracted gravitationally from the surrounding nebula."
(https://esahubble.org/images/opo9935a)

I like this HH object, but unfortunately I can't see any typical jets or discs of gas and dust here...

Image
jac berne (flickr)

Don't ask me about the disk of gas and dust, but the jets are here:



The jets look green and blue in this Hubble image - or rather, the green and blue stuff is hydrogen and sulfur that has been ionized by jets from HH32!

Of course, the true color of ionized hydrogen and sulfur is red. So, therefore, the red stuff in the image you posted is hydrogen and sulfur that has been ionized by jets!

Ann
ThanX Ann
I understand. Your explanations are helpful!
Jac

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Re: APOD: LDN 673: Dark Clouds in Aquila (2022 Oct 29)

Post by orin stepanek » Sat Oct 29, 2022 8:13 pm

LDN673_1024.jpg
So much is hidden in the universe!
opo9935a.jpg
opa9935a APOD reveals them! Thank you!
2306_dark_energy_detail.jpg
My favorite poster for Halloween!! 8-) :D
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