APOD: A Sagittarius Starscape (2014 Sep 05)

Comments and questions about the APOD on the main view screen.
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APOD Robot
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APOD: A Sagittarius Starscape (2014 Sep 05)

Post by APOD Robot » Fri Sep 05, 2014 4:07 am

Image A Sagittarius Starscape

Explanation: This rich starscape spans nearly 7 degrees on the sky, toward the Sagittarius spiral arm and the center of our Milky Way galaxy. A telescopic mosaic, it features well-known bright nebulae and star clusters cataloged by 18th century cosmic tourist Charles Messier. Still popular stops for skygazers M16, the Eagle (far right), and M17, the Swan (near center) nebulae are the brightest star-forming emission regions. With wingspans of 100 light-years or so, they shine with the telltale reddish glow of hydrogen atoms from over 5,000 light-years away. Colorful open star cluster M25 near the upper left edge of the scene is closer, a mere 2,000 light-years distant and about 20 light-years across. M24, also known as the Sagittarius Star Cloud, crowds in just left of center along the bottom of the frame, fainter and more distant Milky Way stars seen through a narrow window in obscuring fields of interstellar dust.

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Boomer12k
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Re: APOD: A Sagittarius Starscape (2014 Sep 05)

Post by Boomer12k » Fri Sep 05, 2014 8:23 am

Looks like a guy sitting down in the middle of his cave....The Swan Nebula is his FAcE...he is looking down at his hands. It is dark in his cave, so you only get impressions.

really awesome mosaic...well done.


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starsurfer
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Re: APOD: A Sagittarius Starscape (2014 Sep 05)

Post by starsurfer » Fri Sep 05, 2014 8:33 am

I love widefield mosaics and this is one of the best ones I've seen! I much prefer viewing this image after rotating it 90 degrees to north up. There are lots of nebulae visible in this image, some might even be uncatalogued! I'm pleased it includes one of my favourite nebulae in Sagittarius, NGC 6589 near the bottom left corner. A labeled version (with many things not labeled) can be seen here: http://nova.astrometry.net/annotated_full/831359

Alistair Symon did a mosaic with a similar field of view 2 years ago: http://www.woodlandsobservatory.com/M16 ... 906_12.htm

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Re: APOD: A Sagittarius Starscape (2014 Sep 05)

Post by visual_astronomer » Fri Sep 05, 2014 4:37 pm

Having just spent several hours last new Moon observing this region with my 20" scope, I can assure you that this it doesn't look anything like this.

Still, it is a lovely picture.

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geckzilla
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Re: APOD: A Sagittarius Starscape (2014 Sep 05)

Post by geckzilla » Fri Sep 05, 2014 5:28 pm

visual_astronomer wrote:Having just spent several hours last new Moon observing this region with my 20" scope, I can assure you that this it doesn't look anything like this.

Still, it is a lovely picture.
Of course it doesn't look like this to our simple human eyes. I'm thankful that we have instruments which can faithfully produce images of what's really out there which our eyes can understand, though. What if we didn't? We would be limited to sunsets, the moon, eclipses, the brightest, nearest stars, faint apparitions of the galactic core and Magellanic clouds and two blurry, nearby galaxies, otherwise. Astronomy would be seriously hampered.
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starsurfer
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Re: APOD: A Sagittarius Starscape (2014 Sep 05)

Post by starsurfer » Sun Sep 07, 2014 1:55 pm

visual_astronomer wrote:Having just spent several hours last new Moon observing this region with my 20" scope, I can assure you that this it doesn't look anything like this.

Still, it is a lovely picture.
There is a huge difference between what you can observe visually and what can be seen in a long exposure photograph taken with a camera. A camera can capture more light than the human eye, therefore fainter things are visible.