Page 1 of 1

APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 5:07 am
by APOD Robot
Image Massive Stars in NGC 6357

Explanation: Massive stars lie within NGC 6357, an expansive emission nebula complex some 6,500 light-years away toward the tail of the constellation Scorpius. In fact, positioned near center in this ground-based close-up of NGC 6357, star cluster Pismis 24 includes some of the most massive stars known in the galaxy, stars with nearly 100 times the mass of the Sun. The nebula's bright central region also contains dusty pillars of molecular gas, likely hiding massive protostars from the prying eyes of optical instruments. Intricate shapes in the nebula are carved as interstellar winds and energetic radiation from the young and newly forming massive stars clear out the natal gas and dust and power the nebular glow. Enhancing the nebula's cavernous appearance, narrowband image data was included in this composite color image in a Hubble palette scheme. Emission from sulfur, hydrogen, and oxygen atoms is shown in red green and blue hues. The alluring telescopic view spans about 50 light-years at the estimated distance of NGC 6357.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 5:21 am
by Beyond
It looks like a very good painting, to me.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 7:08 am
by Boomer12k
OK....a massive Mickey Mouse BEAR....looking at a glowing frog...with a weird alien DOCTOR looking on....surrounded by SHENRON of Dragon Ball Z...his head is in the middle at the top, looking down at the bear.... :lol2:

And many other things in this GREAT IMAGE...

:---[===] *

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 10:30 am
by heehaw
"There's a hole in the bottom of the sea
There's a hole in the bottom of the sea
There's a hole
There's a hole
There's a hole in the bottom of the sea
....and it seems that there is also a hole in the top of the sky!

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 3:46 pm
by NCTom
How will the mass of these new giants affect their lifespan and the type of ending we might expect?

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 3:55 pm
by Chris Peterson
NCTom wrote:How will the mass of these new giants affect their lifespan and the type of ending we might expect?
They will only produce energy for a few million years, before exploding in supernovas, which will produce gas and dust to seed future nebulas.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 6:03 pm
by Bobarino
1. The black pillar just to right of center looks a little like Godzilla. Just saying.

2. Almost all images I've seen have "enhanced" or "added" color. Are there any true color images of these objects, or are they all taken in B&W and color added later?

Thanks

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 6:08 pm
by RPeto@ctsu.ox.ac.uk
The image is mostly red, which presumably must represent hydrogen rather than the much less common sulfur. Yet, the legend says: "Emission from sulfur, hydrogen, and oxygen atoms is shown in red, green, and blue hues." Is this a mistake? Should it instead say "hydrogen, sulfur and oxygen"??

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 6:21 pm
by Chris Peterson
RPeto@ctsu.ox.ac.uk wrote:The image is mostly red, which presumably must represent hydrogen rather than the much less common sulfur. Yet, the legend says: "Emission from sulfur, hydrogen, and oxygen atoms is shown in red, green, and blue hues." Is this a mistake? Should it instead say "hydrogen, sulfur and oxygen"??
No mistake. This image utilizes the common Hubble palette, which maps SII to red, Ha (and usually, NII) to green, and OIII to blue.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 6:24 pm
by Chris Peterson
Bobarino wrote:1. The black pillar just to right of center looks a little like Godzilla. Just saying.

2. Almost all images I've seen have "enhanced" or "added" color. Are there any true color images of these objects, or are they all taken in B&W and color added later?
If you just follow the link in the caption to the author page you'll find an RGB version that approximates "true" color.

All images (even from your consumer camera) are made in B&W and then the color is generated from separate filtered channels.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 6:25 pm
by starsurfer
Bobarino wrote:1. The black pillar just to right of center looks a little like Godzilla. Just saying.

2. Almost all images I've seen have "enhanced" or "added" color. Are there any true color images of these objects, or are they all taken in B&W and color added later?

Thanks
This image would have made an excellent mouseover with the true colour version, which can be found here.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 6:55 pm
by Chris Peterson
starsurfer wrote:This image would have made an excellent mouseover with the true colour version, which can be found here.
Click to view full size image 1 or image 2
(I posted these for the moment on my own site... I don't mean to step on the copyright of the authors. Is there a way to do an imghover with uploaded images, rather than linked ones?)

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Fri Feb 05, 2016 10:32 pm
by geckzilla
Chris Peterson wrote:
starsurfer wrote:This image would have made an excellent mouseover with the true colour version, which can be found here.
Click to view full size image 1 or image 2
(I posted these for the moment on my own site... I don't mean to step on the copyright of the authors. Is there a way to do an imghover with uploaded images, rather than linked ones?)
Yes, you just use the links to the uploaded images and then encase the uploaded images within a "hide" tag after placing them inline. Sometimes I'll put them on my own site too, though. I don't think most people would be bothered by that as long as it's only used in the context of discussing an APOD. What really bothers content creators is when their content gets automatically scraped by bots and then adverts are placed all around them and they feel someone is profiting from their work.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Sat Feb 06, 2016 1:52 am
by MarkBour
Hmmm ... I can't wait for Art to read that last sentence, to see what he comes up with :-)

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Sat Feb 06, 2016 2:22 am
by neufer
MarkBour wrote:
Hmmm ... I can't wait for Art to read that last sentence, to see what he comes up with :-)
Hmmm ... Which last sentence :?:

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Sat Feb 06, 2016 9:44 pm
by MarkBour
neufer wrote:
MarkBour wrote: Hmmm ... I can't wait for Art to read that last sentence, to see what he comes up with :-)
Hmmm ... Which last sentence :?:
geckzilla wrote:... What really bothers content creators is when their content gets automatically scraped by bots and then adverts are placed all around them and they feel someone is profiting from their work.
... which I figured you would take as a challenge. :-)

My take on it would be :
Come see the NGC 6357 show! We've got the biggest stars in the galaxy!
Advert.gif

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Sun Feb 07, 2016 4:28 am
by neufer
MarkBour wrote:
neufer wrote:
MarkBour wrote: Hmmm ... I can't wait for Art to read that last sentence, to see what he comes up with :-)
Hmmm ... Which last sentence :?:
geckzilla wrote:
... What really bothers content creators is when their content gets automatically scraped by bots and then adverts are placed all around them and they feel someone is profiting from their work.
  • Sonnet 119
So I return rebuked to my content
And gain by ill thrice more than I have spent.

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Sun Feb 07, 2016 5:19 am
by Ann
For a mapped color image, I find this one very intriguing and even rather beautiful. I'm partcularly struck by the bright, light blue area "below" the main star cluster and the bright yellow "chrysalis" surrounding a star that is still wrapped in its native cloud. The light blue area must be extremely rich in oxygen, and moderately rich in hydrogen and sulphur too? Otherwise why is the area light blue rather than more royal blue?

The yellow area must be extremely rich in both hydrogen and sulphur, but it must lack oxygen, I think. OIII emission is only found in rarefied conditions, and the yellow area is presumably full of cosmic gunk.

All in all, this is a very fascinating image.

Ann

Re: APOD: Massive Stars in NGC 6357 (2016 Feb 05)

Posted: Mon Feb 08, 2016 3:29 am
by MarkBour
neufer wrote:
  • Sonnet 119
So I return rebuked to my content
And gain by ill thrice more than I have spent.
“most expensive originals have cheap imitations.”
― Elfriede Jelinek, The Piano Teacher