APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

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APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by APOD Robot » Tue Jun 11, 2024 4:05 am

Image Colorful Stars and Clouds near Rho Ophiuchi

Explanation: Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty? The colors result from a mixture of objects and processes. Fine dust -- illuminated by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the upper right of the featured image. The Rho Ophiuchi star system lies at the center of the blue reflection nebula on the left, while a different reflection nebula, IC 4605, lies just below and right of the image center. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum.

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Ann
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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by Ann » Tue Jun 11, 2024 6:54 am

Wow, today's APOD makes me think of the art of William Turner!


And today's APOD also makes me think of another "astronomy-as-art" portrait of the Rho Ophiuchi Molecular Complex, aptly named the Rho Ophiuchi Molecular Complex:

APOD 11 June annotated.png
Colorful Stars and Clouds near Rho Ophiuchi
Image Credit & Copyright: Craig Stocks
Rho Ophiuchi Molecular Complex annotated Fermin Jiménez Najar.png
Rho Ophiuchi Molecular Complex, Credit: Fermin Jiménez Najar


As you can see, if you compare the APOD by Craig Stocks and the picture by Fermin Jiménez Najar, you can see that the APOD has a smaller field of view. We don't see Sigma Scorpii or Tau Scorpii (and their extended nebulas) in the APOD.

A very interesting but relatively unsung part of the Antares-Rho Ophiuchi complex is IC 4603, where star formation is in full swing:


Another infrared image reveals the distribution of dust around Antares, Sigma and Tau Scorpii, Rho Ophiuchi and IC 4603:


Interestingly, the stars of the Antares/Rho Ophiuchi region appear to be of different ages. According to Wikipedia, Antares is believed to have a mass of about 12 solar masses, originally 15-17 solar masses, and its age is believed to be about 12 million years (or 11-15 million years). By comparison, Wikipedia says that the most massive component of Sigma Scorpii is believed to have a mass of 18.4±5.4 M - all right, that a large uncertainty, but it still suggests that the most massive component of Sigma Scorpii is more massive than Antares. The only way that works is if Sigma Scorpii is younger than Antares, and indeed it is believed to be: 8-10 million years for Sigma versus 11-15 years for Antares.

Tau Scorpii is believed to be even younger, some 6 million years. I haven't been able to find an age estimate for Rho Ophiuchi, but in view of the fact that it is a star of spectral class B2 and it appears to be at least a little bit evolved, it could well be as old as Antares or even slightly older (20 million years?).

The beautiful Antares-Rho Ophiuchi molecular cloud, and its illuminating stars, are part of the Scorpius-Centaurus association.

Wikipedia wrote:

The Scorpius–Centaurus association (sometimes called Sco–Cen or Sco OB2) is the nearest OB association to the Sun. This stellar association is composed of three subgroups (Upper Scorpius, Upper Centaurus–Lupus, and Lower Centaurus–Crux) and its distance is about 130 parsecs or 420 light-years.

And that's all from me today! :D

Ann
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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by Roy » Tue Jun 11, 2024 1:14 pm

My first thought was ‘how can an antique side wheel steam tug risk towing a 98-gun battleship with all its top hamper up’ which sent me to searching the Temeraire on Wikipedia. The articles are fascinating. The picture and painter are on the £20 note. FYI The British have turns oF phrase relating to old currency which are interesting - Mark Steyn recently wrote something wasn’t worth “tuppence three-farthings”, two old British coins.
And in answer to the thought: all the guns, hardware, masts, spars, sails, and cordage were salvaged before the ship was sold to the breakers.

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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by AVAO » Tue Jun 11, 2024 6:53 pm

Ann wrote: Tue Jun 11, 2024 6:54 am Wow, today's APOD makes me think of the art of William Turner!


And today's APOD also makes me think of another "astronomy-as-art" portrait of the Rho Ophiuchi Molecular Complex, aptly named the Rho Ophiuchi Molecular Complex:

APOD 11 June annotated.png
Colorful Stars and Clouds near Rho Ophiuchi
Image Credit & Copyright: Craig Stocks
Rho Ophiuchi Molecular Complex annotated Fermin Jiménez Najar.png
Rho Ophiuchi Molecular Complex, Credit: Fermin Jiménez Najar


As you can see, if you compare the APOD by Craig Stocks and the picture by Fermin Jiménez Najar, you can see that the APOD has a smaller field of view. We don't see Sigma Scorpii or Tau Scorpii (and their extended nebulas) in the APOD.

A very interesting but relatively unsung part of the Antares-Rho Ophiuchi complex is IC 4603, where star formation is in full swing:


Another infrared image reveals the distribution of dust around Antares, Sigma and Tau Scorpii, Rho Ophiuchi and IC 4603:


Interestingly, the stars of the Antares/Rho Ophiuchi region appear to be of different ages. According to Wikipedia, Antares is believed to have a mass of about 12 solar masses, originally 15-17 solar masses, and its age is believed to be about 12 million years (or 11-15 million years). By comparison, Wikipedia says that the most massive component of Sigma Scorpii is believed to have a mass of 18.4±5.4 M - all right, that a large uncertainty, but it still suggests that the most massive component of Sigma Scorpii is more massive than Antares. The only way that works is if Sigma Scorpii is younger than Antares, and indeed it is believed to be: 8-10 million years for Sigma versus 11-15 years for Antares.

Tau Scorpii is believed to be even younger, some 6 million years. I haven't been able to find an age estimate for Rho Ophiuchi, but in view of the fact that it is a star of spectral class B2 and it appears to be at least a little bit evolved, it could well be as old as Antares or even slightly older (20 million years?).

The beautiful Antares-Rho Ophiuchi molecular cloud, and its illuminating stars, are part of the Scorpius-Centaurus association.

Wikipedia wrote:

The Scorpius–Centaurus association (sometimes called Sco–Cen or Sco OB2) is the nearest OB association to the Sun. This stellar association is composed of three subgroups (Upper Scorpius, Upper Centaurus–Lupus, and Lower Centaurus–Crux) and its distance is about 130 parsecs or 420 light-years.

And that's all from me today! :D

Ann
ThanX Ann

I think your detailed explanations and words of praise also appeal to Craig Stocks, an old expert in the astrophotography business.
His mission is to see astrophotography as art and not just as science, which your explanations and the comparison with William Turner perfectly underline.

Personally, I am a little bit irritated by the unusual perspective and the many missing stars in the area. I also love Turner as a master of light. Here, too, the APOD image is a bit too exaggerated for me and the cloud structures a bit too harsh. In contrast, the level of detail and the resolution of the cloud structures is astonishing. But as I said, you shouldn't argue about art.
In the following image, Craig Stocks shows very well that he can do things differently if he has a different intention:
https://craigstocksarts.smugmug.com/Lan ... -8tgDXRZ/A


From a scientific point of view, the star formation region around IC 4603 is really very exciting.

Composit infill (JWST)

ALLWISE / SST

NASA / ESA (JWST) ZOOM: https://esahubble.org/images/weic2316a/zoomable/

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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by Ann » Wed Jun 12, 2024 4:24 am

AVAO wrote: Tue Jun 11, 2024 6:53 pm
ThanX Ann

I think your detailed explanations and words of praise also appeal to Craig Stocks, an old expert in the astrophotography business.
His mission is to see astrophotography as art and not just as science, which your explanations and the comparison with William Turner perfectly underline.

Personally, I am a little bit irritated by the unusual perspective and the many missing stars in the area. I also love Turner as a master of light. Here, too, the APOD image is a bit too exaggerated for me and the cloud structures a bit too harsh. In contrast, the level of detail and the resolution of the cloud structures is astonishing. But as I said, you shouldn't argue about art.
In the following image, Craig Stocks shows very well that he can do things differently if he has a different intention:
https://craigstocksarts.smugmug.com/Lan ... -8tgDXRZ/A


From a scientific point of view, the star formation region around IC 4603 is really very exciting.

Composit infill (JWST)

ALLWISE / SST

NASA / ESA (JWST) ZOOM: https://esahubble.org/images/weic2316a/zoomable/
Thanks, Jac, for all your additional pictures. I love the picture where you placed the (tiny) star formation in IC 4603 smack dab in the darkest part of the long "double dust lane" reaching all the way from the plane of the Milky Way into the heart of the Antares-Rho Ophiuchi molecular cloud.


I also love your link the the gorgeous Antares-Sigma Scorpii picture by Craig Stocks! :D

Ann
Last edited by Ann on Thu Jun 13, 2024 3:50 am, edited 1 time in total.
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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by Chris Peterson » Wed Jun 12, 2024 1:05 pm

Is the caption yours? Just wondering if you found some discussion of this. From the image alone, I'd say that the dust is either not associated with the star formation region (e.g. simply lies between us and it), or to the extent it is very close, is traveling outward, not inward.

Dust doesn't really feed star formation, it merely helps trigger it when enough hydrogen is already present.
Chris

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Ann
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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by Ann » Wed Jun 12, 2024 1:16 pm

Chris Peterson wrote: Wed Jun 12, 2024 1:05 pm
Is the caption yours? Just wondering if you found some discussion of this. From the image alone, I'd say that the dust is either not associated with the star formation region (e.g. simply lies between us and it), or to the extent it is very close, is traveling outward, not inward.

Dust doesn't really feed star formation, it merely helps trigger it when enough hydrogen is already present.
It's my caption and my interpretation. I may certainly be wrong.

Ann
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Re: APOD: Colorful Stars and Clouds near Rho... (2024 Jun 11)

Post by AVAO » Wed Jun 12, 2024 8:21 pm

Ann wrote: Wed Jun 12, 2024 4:24 am
Thanks, Jac, for all your additional pictures. I love the picture where you placed the (tiny) star formation in NGC 4603 smack dab in the darkest part of the long "double dust lane" reaching all the way from the plane of the Milky Way into the heart of the Antares-Rho Ophiuchi molecular cloud.


I also love your link the the gorgeous Antares-Sigma Scorpii picture by Craig Stocks! :D

Ann
ThanX Ann 4 your great comment as always.

Just a small correction to remain formally correct.
The region is called IC 4603. (NGC 4603 is in a different location.)

Regarding the caption, I also think that the star formation of the Antares-Rho Ophiuchi region is feeding the 'double dust lane',
or that the dust is moving outwards and not the other way around.

Jac