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APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 4:09 am
by APOD Robot
Image Chamaeleon I Molecular Cloud

Explanation: Dark markings and bright nebulae in this telescopic southern sky view are telltale signs of young stars and active star formation. They lie a mere 650 light-years away, at the boundary of the local bubble and the Chamaeleon molecular cloud complex. Regions with young stars identified as dusty reflection nebulae from the 1946 Cederblad catalog include the C-shaped Ced 110 just above and right of center, and bluish Ced 111 below it. Also a standout in the frame, the orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees. That's about 17 light-years at the estimated distance of the nearby Chamaeleon I molecular cloud.

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Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 6:06 pm
by johnnydeep
They lie a mere 650 light-years away, at the boundary of the local bubble and the Chamaeleon molecular cloud complex.
The orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees. That's about 17 light-years at the estimated distance of the nearby Chamaeleon I molecular cloud
Someone please explain!

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 6:39 pm
by Ann
Cederblad111-110_1024[1].jpg
Chamaeleon I Molecular Cloud
Image Credit & Copyright: Amiel Contuliano

No one has had anything to say about today's APOD, eh?

Well, it's a nice picture of a very young region of low-mass star formation. Actually I shy away a little from the expression "low-mass star formation", because any site of star formation that forms A-type stars deserves to be called, if you ask me, at least a medium-mass region of star formation. Honestly, do you realize how extremely common the little red dwarfs are and how respectably "medium-massive" the Sun is by comparison?

The Sun's neighbors. Note the huge numbers of little red dwarfs. The Sun is the second yellow star from the top, with Alpha Centauri A being the brightest and most massive of the yellow stars. Sirius and Procyon are the only blue stars here. Credit: I don't know.


I apologize for the tiny size of the picture above, which makes it impossible to read the lettering. But the picture does bring home an important message: The little red dwarfs are just so numerous, and the Sun is actually pretty bright and massive compared with most stars in the Milky Way.

(And if you are wondering about the grayish-colored stars in the graph, I think these represent stars of a certain temperature and luminosity that, however, can't be found in the solar neighborhood.)


So, the Chameleon I molecular cloud. We have every reason to believe that the stars that are seen in reflection nebulas in this part of the sky are very young indeed, and that the clouds of gas and dust that they light up are indeed these stars' own birth cocoons. 👶


The star that lights up the blue reflection nebula in the APOD is CU Chameleon, and it is, for its spectral class of A0V, shockingly faint! :shock: With a a Gaia parallax that puts it only 600 light-years away from us, and with an apparent V luminosity of +9.0, its true V luminosity is only twice that of the Sun! 🌞🌞

Compare CU Chameleon with our bright A1V-type neighbor Sirius, whose V luminosity is 22 times that of the Sun!! 🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞

Why is CU Chameleon so faint for its spectral class? One reason is that it has lost so much of its light to its own reflection nebula! But the most important reason for its faintness is that it is so young.

Main sequence stars, those that fuse hydrogen to helium in their cores, get brighter and brighter as they age. If you ask me, the math idiot, the reason for this continuous brightening is that larger and larger parts of the star's interior get involved in the fusion of hydrogen into helium as the star ages. Sirius, according to Wikipedia, is 242±5 million years old (and don't ask me how they arrived at such an exact age). CU Chameleon, by contrast, is (I'm guessing) hardly more than 5 million years old, and it could well be younger.

One absolutely great aspect of today's APOD is that the colors are perfect. They are! 😀 For example, it is very easy to identify CU Chameleon in the APOD, because it is the only blue star in the image. The fascinating C-shaped nebula is white to yellow-white, and my guess is that it is lit up by a yellow-orange K-type star. And the little arrowhead-shaped nebula below CU Chameleon is strikingly orange, probably because a tiny and very orange little red dwarf is forming there.

A picture where the colors are not so perfect, because the image has a bluish cast, is nevertheless a gorgeous portrait of the Chameleon I Molecular Cloud:

The Chameleon I Molecular Cloud. Credit: Stas Volskiy at Cloudy NIghts.


Lovely, isn't it? I think the details are gorgeous, and I really get the impression that a lot of (mostly small) stars are forming here. And no, the orientation of Stas Volskiy's picture is not the same as the APOD.

A larger-field image of the Chameleon I Molecular Cloud shows us the starforming site IC 2631 not far from CU Chameleon and Cederblad 111:

IC+2631+LRGB+rev+Final+CDK+1000+25+Jan+2023small[1].jpg
IC 2631. A lot of small stars are forming in the dark cloud
"above" bright blue star HD 97300. Credit: Mark Hanson.
Cederblad 111, if you can't find it, is in the upper right quadrant of the image, directly below IC 2631. Credit: oldwexi at Astrobin.


And, yeah. HD 97300, illuminating star of IC 2361, is spectral class B9V, so it's a tad hotter than CU Chameleon. But this wet-behind-its-ears youngster is about as faint for its spectral class a CU Chameleon: Only 3 solar luminosities! 🌞🌞🌞

Ann

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 6:48 pm
by AVAO
johnnydeep wrote: ↑Mon May 27, 2024 6:06 pm
They lie a mere 650 light-years away, at the boundary of the local bubble and the Chamaeleon molecular cloud complex.
The orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees. That's about 17 light-years at the estimated distance of the nearby Chamaeleon I molecular cloud
Someone please explain!
Well, in reality it should be around 25 light years. but at 650 light years distance we shouldn't be too petty ;-)
https://apod.nasa.gov/apod/ap220217.html

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 6:52 pm
by johnnydeep
AVAO wrote: ↑Mon May 27, 2024 6:48 pm
johnnydeep wrote: ↑Mon May 27, 2024 6:06 pm
They lie a mere 650 light-years away, at the boundary of the local bubble and the Chamaeleon molecular cloud complex.
The orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees. That's about 17 light-years at the estimated distance of the nearby Chamaeleon I molecular cloud
Someone please explain!
Well, in reality it should be around 25 light years. but at 650 light years distance we shouldn't be too petty ;-)
https://apod.nasa.gov/apod/ap220217.html
<sigh> I'm an idiot. I misread that as stating a 17 ly distance instead of the diameter of the view at the 650 ly distance.

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 6:52 pm
by AVAO
Ann wrote: ↑Mon May 27, 2024 6:39 pm
Cederblad111-110_1024[1].jpg
Chamaeleon I Molecular Cloud
Image Credit & Copyright: Amiel Contuliano

No one has had anything to say about today's APOD, eh?

Well, it's a nice picture of a very young region of low-mass star formation. Actually I shy away a little from the expression "low-mass star formation", because any site of star formation that forms A-type stars deserves to be called, if you ask me, at least a medium-mass region of star formation. Honestly, do you realize how extremely common the little red dwarfs are and how respectably "medium-massive" the Sun is by comparison?


I apologize for the tiny size of the picture above, which makes it impossible to read the lettering. But the picture does bring home an important message: The little red dwarfs are just so numerous, and the Sun is actually pretty bright and massive compared with most stars in the Milky Way.

(And if you are wondering about the grayish-colored stars in the graph, I think these represent stars of a certain temperature and luminosity that, however, can't be found in the solar neighborhood.)


So, the Chameleon I molecular cloud. We have every reason to believe that the stars that are seen in reflection nebulas in this part of the sky are very young indeed, and that the clouds of gas and dust that they light up are indeed these stars' own birth cocoons. 👶


The star that lights up the blue reflection nebula in the APOD is CU Chameleon, and it is, for its spectral class of A0V, shockingly faint! :shock: With a a Gaia parallax that puts it only 600 light-years away from us, and with an apparent V luminosity of +9.0, its true V luminosity is only twice that of the Sun! 🌞🌞

Compare CU Chameleon with our bright A1V-type neighbor Sirius, whose V luminosity is 22 times that of the Sun!! 🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞🌞

Why is CU Chameleon so faint for its spectral class? One reason is that it has lost so much of its light to its own reflection nebula! But the most important reason for its faintness is that it is so young.

Main sequence stars, those that fuse hydrogen to helium in their cores, get brighter and brighter as they age. If you ask me, the math idiot, the reason for this continuous brightening is that larger and larger parts of the star's interior get involved in the fusion of hydrogen into helium as the star ages. Sirius, according to Wikipedia, is 242±5 million years old (and don't ask me how they arrived at such an exact age). CU Chameleon, by contrast, is (I'm guessing) hardly more than 5 million years old, and it could well be younger.

One absolutely great aspect of today's APOD is that the colors are perfect. They are! 😀 For example, it is very easy to identify CU Chameleon in the APOD, because it is the only blue star in the image. The fascinating C-shaped nebula is white to yellow-white, and my guess is that it is lit up by a yellow-orange K-type star. And the little arrowhead-shaped nebula below CU Chameleon is strikingly orange, probably because a tiny and very orange little red dwarf is forming there.

A picture where the colors are not so perfect, because the image has a bluish cast, is nevertheless a gorgeous portrait of the Chameleon I Molecular Cloud:


Lovely, isn't it? I think the details are gorgeous, and I really get the impression that a lot of (mostly small) stars are forming here. And no, the orientation of Stas Volskiy's picture is not the same as the APOD.

A larger-field image of the Chameleon I Molecular Cloud shows us the starforming site IC 2631 not far from CU Chameleon and Cederblad 111:

IC+2631+LRGB+rev+Final+CDK+1000+25+Jan+2023small[1].jpg
IC 2631. A lot of small stars are forming in the dark cloud
"above" bright blue star HD 97300. Credit: Mark Hanson.

And, yeah. HD 97300, illuminating star of IC 2361, is spectral class B9V, so it's a tad hotter than CU Chameleon. But this wet-behind-its-ears youngster is about as faint for its spectral class a CU Chameleon: Only 3 solar luminosities! 🌞🌞🌞

Ann


Today's APOD is great and so are your wonderful explanations. Thank you very much Ann!

Click to view full size image
Background picture: Chamaeleon I Molecular Cloud Image Credit & Copyright: Amiel Contuliano
https://www.astrobin.com/32d8tb/


Click to view full size image
Chamaeleon I molecular cloud NASA's James Webb Space Telescope's Near-Infrared Camera (NIRCam) captured an image of the heart of the Chamaeleon I dark molecular cloud, located 630 light years away. The blue center cloud material appears to be illuminated by the orange protostar Ced 110 IRS 4, over on the left. The orange dots behind the cloud are numerous background stars; the light can be used to detect ice within the cloud through the absorption of passing starlight. NASA / ESA / CSA
https://www.planetary.org/space-images/ ... ular-cloud

Click to view full size image
Two stars shine through the centre of a ring of cascading dust in this image taken by the NASA/ESA Hubble Space Telescope. The star system is named DI Cha, and while only two stars are apparent, it is actually a quadruple system containing two sets of binary stars. As this is a relatively young star system it is surrounded by dust. The young stars are moulding the dust into a wispy wrap. The host of this alluring interaction between dust and star is the Chamaeleon I dark cloud — one of three such clouds that comprise a large star-forming region known as the Chamaeleon Complex. DI Cha's juvenility is not remarkable within this region. In fact, the entire system is among not only the youngest but also the closest collections of newly formed stars to be found and so provides an ideal target for studies of star formation.
Credit: ESA/Hubble & NASA Acknowledgement: Judy Schmidt (geckzilla.org)

Click to view full size image
A nursery for unruly young stars
This striking new image, captured by the NASA/ESA Hubble Space Telescope, reveals a star in the process of forming within the Chamaeleon cloud. This young star is throwing off narrow streams of gas from its poles — creating this ethereal object known as HH 909A. These speedy outflows collide with the slower surrounding gas, lighting up the region. When new stars form, they gather material hungrily from the space around them. A young star will continue to feed its huge appetite until it becomes massive enough to trigger nuclear fusion reactions in its core, which light the star up brightly. Before this happens, new stars undergo a phase during which they violently throw bursts of material out into space. This material is ejected as narrow jets that streak away into space at breakneck speeds of hundreds of kilometres per second, colliding with nearby gas and dust and lighting up the region. The resulting narrow, patchy regions of faintly glowing nebulosity are known as Herbig-Haro objects. They are very short-lived structures, and can be seen to visibly change and evolve over a matter of years (heic1113) — just the blink of an eye on astronomical timescales. [...] A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Judy Schmidt.
Credit: NASA & ESA.Acknowledgements: Kevin Luhman (Pennsylvania State University), and Judy Schmidt

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 7:26 pm
by Ann
AVAO wrote: ↑Mon May 27, 2024 6:52 pm
Today's APOD is great and so are your wonderful explanations. Thank you very much Ann!
Background picture: Chamaeleon I Molecular Cloud Image Credit & Copyright: Amiel Contuliano
https://www.astrobin.com/32d8tb/


Chamaeleon I molecular cloud NASA's James Webb Space Telescope's Near-Infrared Camera (NIRCam) captured an image of the heart of the Chamaeleon I dark molecular cloud, located 630 light years away. The blue center cloud material appears to be illuminated by the orange protostar Ced 110 IRS 4, over on the left. The orange dots behind the cloud are numerous background stars; the light can be used to detect ice within the cloud through the absorption of passing starlight. NASA / ESA / CSA
https://www.planetary.org/space-images/ ... ular-cloud

Two stars shine through the centre of a ring of cascading dust in this image taken by the NASA/ESA Hubble Space Telescope. The star system is named DI Cha, and while only two stars are apparent, it is actually a quadruple system containing two sets of binary stars. As this is a relatively young star system it is surrounded by dust. The young stars are moulding the dust into a wispy wrap. The host of this alluring interaction between dust and star is the Chamaeleon I dark cloud — one of three such clouds that comprise a large star-forming region known as the Chamaeleon Complex. DI Cha's juvenility is not remarkable within this region. In fact, the entire system is among not only the youngest but also the closest collections of newly formed stars to be found and so provides an ideal target for studies of star formation.
Credit: ESA/Hubble & NASA Acknowledgement: Judy Schmidt (geckzilla.org)

A nursery for unruly young stars
This striking new image, captured by the NASA/ESA Hubble Space Telescope, reveals a star in the process of forming within the Chamaeleon cloud. This young star is throwing off narrow streams of gas from its poles — creating this ethereal object known as HH 909A. These speedy outflows collide with the slower surrounding gas, lighting up the region. When new stars form, they gather material hungrily from the space around them. A young star will continue to feed its huge appetite until it becomes massive enough to trigger nuclear fusion reactions in its core, which light the star up brightly. Before this happens, new stars undergo a phase during which they violently throw bursts of material out into space. This material is ejected as narrow jets that streak away into space at breakneck speeds of hundreds of kilometres per second, colliding with nearby gas and dust and lighting up the region. The resulting narrow, patchy regions of faintly glowing nebulosity are known as Herbig-Haro objects. They are very short-lived structures, and can be seen to visibly change and evolve over a matter of years (heic1113) — just the blink of an eye on astronomical timescales. [...] A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Judy Schmidt.
Credit: NASA & ESA.Acknowledgements: Kevin Luhman (Pennsylvania State University), and Judy Schmidt
Thanks, Jac, for your wonderful pictures! :D

Tell me, is HH 909A visible in Stas Volskiy's picture of the Chameleon I Molecular Cloud?

Chameleon I Molecular Cloud with HH 909A Volskiy.png

Ann

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Mon May 27, 2024 7:39 pm
by AVAO
Ann wrote: ↑Mon May 27, 2024 7:26 pm
AVAO wrote: ↑Mon May 27, 2024 6:52 pm
Today's APOD is great and so are your wonderful explanations. Thank you very much Ann!
Background picture: Chamaeleon I Molecular Cloud Image Credit & Copyright: Amiel Contuliano
https://www.astrobin.com/32d8tb/


Chamaeleon I molecular cloud NASA's James Webb Space Telescope's Near-Infrared Camera (NIRCam) captured an image of the heart of the Chamaeleon I dark molecular cloud, located 630 light years away. The blue center cloud material appears to be illuminated by the orange protostar Ced 110 IRS 4, over on the left. The orange dots behind the cloud are numerous background stars; the light can be used to detect ice within the cloud through the absorption of passing starlight. NASA / ESA / CSA
https://www.planetary.org/space-images/ ... ular-cloud

Two stars shine through the centre of a ring of cascading dust in this image taken by the NASA/ESA Hubble Space Telescope. The star system is named DI Cha, and while only two stars are apparent, it is actually a quadruple system containing two sets of binary stars. As this is a relatively young star system it is surrounded by dust. The young stars are moulding the dust into a wispy wrap. The host of this alluring interaction between dust and star is the Chamaeleon I dark cloud — one of three such clouds that comprise a large star-forming region known as the Chamaeleon Complex. DI Cha's juvenility is not remarkable within this region. In fact, the entire system is among not only the youngest but also the closest collections of newly formed stars to be found and so provides an ideal target for studies of star formation.
Credit: ESA/Hubble & NASA Acknowledgement: Judy Schmidt (geckzilla.org)

A nursery for unruly young stars
This striking new image, captured by the NASA/ESA Hubble Space Telescope, reveals a star in the process of forming within the Chamaeleon cloud. This young star is throwing off narrow streams of gas from its poles — creating this ethereal object known as HH 909A. These speedy outflows collide with the slower surrounding gas, lighting up the region. When new stars form, they gather material hungrily from the space around them. A young star will continue to feed its huge appetite until it becomes massive enough to trigger nuclear fusion reactions in its core, which light the star up brightly. Before this happens, new stars undergo a phase during which they violently throw bursts of material out into space. This material is ejected as narrow jets that streak away into space at breakneck speeds of hundreds of kilometres per second, colliding with nearby gas and dust and lighting up the region. The resulting narrow, patchy regions of faintly glowing nebulosity are known as Herbig-Haro objects. They are very short-lived structures, and can be seen to visibly change and evolve over a matter of years (heic1113) — just the blink of an eye on astronomical timescales. [...] A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Judy Schmidt.
Credit: NASA & ESA.Acknowledgements: Kevin Luhman (Pennsylvania State University), and Judy Schmidt
Thanks, Jac, for your wonderful pictures! :D

Tell me, is HH 909A visible in Stas Volskiy's picture of the Chameleon I Molecular Cloud?

Chameleon I Molecular Cloud with HH 909A Volskiy.png

Ann
Well, the honor goes to Judy .-)
HH 909 can be found in the Volskiy picture at the top left.

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Tue May 28, 2024 3:17 pm
by mjsakers
I'm interested in the name of the distant galaxy seen to the right of the cloud in the photo (?)

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Tue May 28, 2024 4:36 pm
by johnnydeep
mjsakers wrote: ↑Tue May 28, 2024 3:17 pm I'm interested in the name of the distant galaxy seen to the right of the cloud in the photo (?)
You mean the tiny one on a direct horizonal line rightward from the brightest star in the center of the blue region? I have no idea. But someone here might!

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Posted: Tue May 28, 2024 5:26 pm
by Ann
mjsakers wrote: ↑Tue May 28, 2024 3:17 pm I'm interested in the name of the distant galaxy seen to the right of the cloud in the photo (?)
The galaxy in question may be ESO 38-6.

It is more or less in the right place.

Ann