Comments and questions about the
APOD on the main view screen.
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heehaw
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by heehaw » Wed Nov 16, 2016 9:52 am
A most striking image!
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JohnD
- Tea Time, Guv! Cheerio!
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by JohnD » Wed Nov 16, 2016 10:44 am
The Holes in the Sky are found!
There are holes in the sky
Where the rain gets in
But they're ever so small
That's why the rain is thin.
Spike Milligan, genius, 1918-2002
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Starry-eyed
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by Starry-eyed » Wed Nov 16, 2016 11:30 am
Why is the red dust clearly visible around these nebulas not also present in front and obscuring the view of their center?
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Chris Peterson
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Contact:
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by Chris Peterson » Wed Nov 16, 2016 1:47 pm
Starry-eyed wrote:Why is the red dust clearly visible around these nebulas not also present in front and obscuring the view of their center?
These are not dusty nebulas. Most of the red you are seeing is actively emitted light from energized gas, not scattered from dust. Many such nebulas show these ring-like structures because material tends to collapse into spherical blobs and to be ejected or dispersed in spherical shells. Such structures appear bright or dense around their edges, where we are looking through lots of material, and thin or transparent in their centers, where we are not. Spherical structure also appears in emission nebulas because we get glowing shells around hot stars or clusters of stars.
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stolenmoment
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by stolenmoment » Wed Nov 16, 2016 2:24 pm
The "Soul" nebula looks more like the "Sole" of a shoe, doesn't it?
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neufer
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by neufer » Wed Nov 16, 2016 3:24 pm
stolenmoment wrote:
The "Soul" nebula looks more like the "Sole" of a shoe, doesn't it?
https://en.wikipedia.org/wiki/Sole_(foot) wrote:
<<The soles of the feet are extremely sensitive to touch due to a high concentration of nerve endings, with as many as 200,000 per sole. This makes them sensitive to surfaces that are walked on, ticklish and some people find them to be erogenous zones.
The beating of the soles of a person's bare feet (foot whipping or bastinado) has served as a traditional means of corporal punishment and discipline in various civilizations to this day and is also used as a method of torture. The purpose of protecting the sole against uncomfortable and harmful impacts of the environment during locomotion initiated the general introduction of footwear in early human history.>>
https://www.scientificamerican.com/article/rats-enjoy-being-tickled-when-they-re-in-the-right-mood-video/ wrote:
Rats Enjoy Being Tickled--When They're in the Right Mood
Scientific American November 10, 2016
By Catherine Caruso
<<“Rats and humans [diverged] maybe 100 million years ago,” [Michael] Brecht says. “But the phenomenon of ticklishness is remarkably similar.” The most telling observation was one he and [Shimpei] Ishiyama didn’t include in their [Science] paper:
Rats, like humans, aren’t ticklish on their hands, but are extremely ticklish on the bottoms of their feet, he says. “It was one of those observations that really made me think that, hey, we're looking at the same thing.”>>
Art Neuendorffer
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revloren
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by revloren » Wed Nov 16, 2016 7:17 pm
neufer wrote: https://www.scientificamerican.com/article/rats-enjoy-being-tickled-when-they-re-in-the-right-mood-video/ wrote:
<<“Rats and humans [diverged] maybe 100 million years ago,” [Michael] Brecht says. “But the phenomenon of ticklishness is remarkably similar.” The most telling observation was one he and [Shimpei] Ishiyama didn’t include in their [Science] paper:
Rats, like humans, aren’t ticklish on their hands, but are extremely ticklish on the bottoms of their feet, he says. “It was one of those observations that really made me think that, hey, we're looking at the same thing.”>>
Rats have hands?
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geckzilla
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by geckzilla » Wed Nov 16, 2016 7:21 pm
revloren wrote: https://www.scientificamerican.com/article/rats-enjoy-being-tickled-when-they-re-in-the-right-mood-video/ wrote:
<<“Rats and humans [diverged] maybe 100 million years ago,” [Michael] Brecht says. “But the phenomenon of ticklishness is remarkably similar.” The most telling observation was one he and [Shimpei] Ishiyama didn’t include in their [Science] paper:
Rats, like humans, aren’t ticklish on their hands, but are extremely ticklish on the bottoms of their feet, he says. “It was one of those observations that really made me think that, hey, we're looking at the same thing.”>>
Rats have hands?
They have a rat-equivalent version of hands. That is to say they don't have human hands. They do have rat hands.
Just call me "geck" because "zilla" is like a last name.
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Fred the Cat
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by Fred the Cat » Wed Nov 16, 2016 8:42 pm
Those little rodents. I love to watch them
handle their food. Obviously
some don't mind being handled.
Ticklish business but some people give their heart and soul.
![:) :ssmile:](./images/smilies/smile.gif)
Freddy's Felicity "Only ascertain as a cat box survivor"
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MarkBour
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by MarkBour » Wed Nov 16, 2016 8:51 pm
stolenmoment wrote:The "Soul" nebula looks more like the "Sole" of a shoe, doesn't it?
Yes, it sure does ... in today's image.
Mark Goldfain
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neufer
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by neufer » Wed Nov 16, 2016 9:54 pm
geckzilla wrote:
They have a rat-equivalent version of hands. That is to say they don't have human hands. They do have rat hands.
https://en.wikipedia.org/wiki/Manus_(anatomy) wrote:
<<The manus (Latin for hand) is the zoological term for the distal portion of the fore limb of an animal. In tetrapods, it is the part of the pentadactyl limb that includes the metacarpals and digits (phalanges). During evolution, it has taken many forms and served a variety of functions. It can be represented by the hand of primates, the lower front limb of hoofed animals or the fore paw and is represented in the wing of birds, bats and prehistoric flying reptiles (pterosaurs), the flipper of marine mammals and the 'paddle' of extinct marine reptiles, such as plesiosaurs and ichthyosaurs.
In cephalopods, the manus is the end, broader part of a tentacle or arm, and its suckers are often larger and arranged differently from those on the rest of the arm.>>
Art Neuendorffer
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Boomer12k
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by Boomer12k » Wed Nov 16, 2016 10:20 pm
Great looking image... would we see this open structure from other angles?
:---[===] *
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NGC3314
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by NGC3314 » Thu Nov 17, 2016 12:55 pm
This is a dusty region overall, almost exactly along the plane of the Milky Way's disk. Right at the bottom of this view are the two nearby galaxies Maffei 1 and 2, so strongly reddened by our local dust that they are dimmed by something like a factor 100 in visible light.
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neufer
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by neufer » Thu Nov 17, 2016 2:31 pm
NGC3314 wrote:
This is a dusty region overall, almost exactly along the plane of the Milky Way's disk. Right at the bottom of this view are the two nearby galaxies Maffei 1 and 2, so strongly reddened by our local dust that they are dimmed by something like a factor 100 in visible light.
https://en.wikipedia.org/wiki/Maffei_1 wrote:
<<Maffei 1 is a giant elliptical galaxy in the constellation Cassiopeia. Maffei 1 lies in the Zone of Avoidance and is heavily obscured by the Milky Way's stars and dust. If it were not obscured, it would be one of the largest (about 3/4 the size of the full moon) brightest and best-known galaxies in the sky. It can be observed visually, using a 30–35 cm or bigger telescope under a very dark sky.>>
https://en.wikipedia.org/wiki/Zone_of_Avoidance wrote:
<<The Zone of Avoidance (ZOA) is the area of the sky that is obscured by the Milky Way. When viewing space from Earth, the attenuation, interstellar dust and stars in the plane of the Milky Way (the galactic plane) obstruct the view of around 20% of the extragalactic sky at visible wavelengths. As a result, optical galaxy catalogues are usually incomplete close to the galactic plane. The Zone of Avoidance was originally called the "Zone of Few Nebulae" [a.k.a., the Proto-ZOA?] in an 1878 paper by English astronomer Richard Proctor that referred to the distribution of "nebulae" in Sir John Herschel's General Catalogue of Nebulae.>>
https://en.wikipedia.org/wiki/Phantom_Zone wrote:
<<The Phantom Zone was discovered by Jor-El and used on the planet Krypton as a method of imprisoning criminals. (Previously, criminals were punished by being sealed into capsules and rocketed into orbit in suspended animation with crystals attached to their foreheads to slowly erase their criminal tendencies.) The inmates of the Phantom Zone reside in a ghost-like state of existence from which they can observe, but cannot interact with, the regular universe. Inmates do not age or require sustenance in the Phantom Zone; furthermore, they are telepathic and mutually insubstantial. Superman periodically released Phantom Zone prisoners whose original sentences had been completed, and most of these went to live in
the bottle city of Kandor.>>
Art Neuendorffer
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DavidLeodis
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by DavidLeodis » Thu Nov 17, 2016 8:43 pm
It's a lovely image
![Smile :)](./images/smilies/icon_smile.gif)
.
I am though somewhat confused as to the what the colours represent. The explanation implies that the red is "energized hydrogen" (presumably Hydrogen alpha, Ha) and in the information with the image in David Lindemann's section in AstoBin it states the image's colours are a "Hybrid Hubble palette" so that may be why the hydrogen is red (what the OIII and SII are coloured is not given). In information that I've found it states "Hubble palette - Ha = Green, OIII = Blue, SII = Red" yet green seems to be uncommonly used to show the presence of Ha. Is the actual Hubble palette not popular when doing astronomy image processing?
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Ann
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by Ann » Sat Nov 19, 2016 5:36 am
DavidLeodis wrote:It's a lovely image
![Smile :)](./images/smilies/icon_smile.gif)
.
I am though somewhat confused as to the what the colours represent. The explanation implies that the red is "energized hydrogen" (presumably Hydrogen alpha, Ha) and in the information with the image in David Lindemann's section in AstoBin it states the image's colours are a "Hybrid Hubble palette" so that may be why the hydrogen is red (what the OIII and SII are coloured is not given). In information that I've found it states "Hubble palette - Ha = Green, OIII = Blue, SII = Red" yet green seems to be uncommonly used to show the presence of Ha. Is the actual Hubble palette not popular when doing astronomy image processing?
I think green is being used here for Ha. Note that the inner parts of the Heart and Soul nebulas are not as much blue as they are aqua-colored or cyan. I think that the blue-green parts we are seeing derive their color from a mixture of Ha and OIII. Similarly, I think the yellow-orange rims are a mixture of Ha and SII.
That said, give me a great RGB picture any day...
Ann
Color Commentator
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DavidLeodis
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by DavidLeodis » Sat Nov 19, 2016 7:20 pm
Ann wrote:DavidLeodis wrote:It's a lovely image
![Smile :)](./images/smilies/icon_smile.gif)
.
I am though somewhat confused as to the what the colours represent. The explanation implies that the red is "energized hydrogen" (presumably Hydrogen alpha, Ha) and in the information with the image in David Lindemann's section in AstoBin it states the image's colours are a "Hybrid Hubble palette" so that may be why the hydrogen is red (what the OIII and SII are coloured is not given). In information that I've found it states "Hubble palette - Ha = Green, OIII = Blue, SII = Red" yet green seems to be uncommonly used to show the presence of Ha. Is the actual Hubble palette not popular when doing astronomy image processing?
I think green is being used here for Ha. Note that the inner parts of the Heart and Soul nebulas are not as much blue as they are aqua-colored or cyan. I think that the blue-green parts we are seeing derive their color from a mixture of Ha and OIII. Similarly, I think the yellow-orange rims are a mixture of Ha and SII.
That said, give me a great RGB picture any day...
Ann
Thank you Ann for your help, which is appreciated
![Smile :)](./images/smilies/icon_smile.gif)
.