I have often looked at the Hubble Deep Field View of all the galaxies that it could see in a very small section of the sky, and have wondered just how small that section of sky was. Well, it turns out that this small section of the sky is about 2.6 arcmin on a side. Using M57, The Ring Nebula, as a comparison, I overlaid it and attempted to show it at the same scale. M57 is 1.4 x 1.0 arcmin.
I know from my imaging of M57 that it is quite tiny and would take a lot of magnification to make it appear larger.
Image #1 is Hubble's Deep Field View. Hubble exposed this region of the sky for about 2 million sec over 50 days. And consists of a stack of over 2000 images. Two different cameras were used: The Advanced Camera for Surveys and the Wide Filed Camera 3 which goes into the near infrared, and they were combined. Consider that this is Hubble's wide angle lens!
Image #2 is M57, taken with Hubble. Again with a bit more detail than I can mange!
Image #3 is my crude attempt to overlay and to try to do it to scale.
Now I can appreciate the size of the area they were using for the image.
By the way, someone has counted ~5500 galaxies in this view. And to think I think I am doing good when I can count 5 or 6!
They also did this long exposure test on another area of the sky and found about the same density of galaxies. And from that, they can estimate the number of galaxies within the range of Hubble at something like a trillion galaxies.
You can go to this site:
https://en.wikipedia.org/wiki/Hubble_Ultra-Deep_FieldAnd there is a section called: Hubble eXtreme Deep Field, and then a video about how the image was taken. Worth watching.
Now that’s perspective!
SonnyE
Loc: Communist California, USA
WOW! Very good Jim!
I remember when I put my Nikon D3300 on my 80 mm telescope, then imaged the Ring Nebula.
The Nikon's sensor takes huge widefield images, and M57 was nearly a small blue spec in the image.
I get hot pixels that would cover up most of those galaxies from the Hubbles image.
Those are objects I doubt I will ever see. They are probably smaller than the air molecules we shoot through.
SonnyE wrote:
WOW! Very good Jim!
I remember when I put my Nikon D3300 on my 80 mm telescope, then imaged the Ring Nebula.
The Nikon's sensor takes huge widefield images, and M57 was nearly a small blue spec in the image.
I get hot pixels that would cover up most of those galaxies from the Hubbles image.
Those are objects I doubt I will ever see. They are probably smaller than the air molecules we shoot through.
Here is a shot of the Ring Nebula taken with an Orion Astrograph 8 inch reflector using a 1.5x crop sensor. The image has not been cropped which means the apparent FOV is as it would be with a 1200mm lens.
This should show how small the Ring Nebula is. And Hubble's eXtreme Deep Field view would be the size of a tiny box surrounding the Ring Nebula.
SonnyE
Loc: Communist California, USA
That's similar to what I wound up with using my Nikon.
Mine was maybe smaller.
I had to look pretty hard to find it, but it looked like the Ring, just tiny.
5 years ago I couldn't have found it. It would have been one of those "Where's Waldo?" things.
Now I can find those little needles in a hay stack.
SonnyE wrote:
That's similar to what I wound up with using my Nikon.
Mine was maybe smaller.
I had to look pretty hard to find it, but it looked like the Ring, just tiny.
5 years ago I couldn't have found it. It would have been one of those "Where's Waldo?" things.
Now I can find those little needles in a hay stack.
I am adding a crop of the moon as a visual as to the comparison in size between the moon and the Ring Nebula at an effective FOV of 1200mm. As you can see, the Ring Nebula is barely larger than a couple large craters seen on the moon.
SonnyE
Loc: Communist California, USA
Well now, there you've got me.
I can't find it. Where's Waldo?
SonnyE wrote:
Well now, there you've got me.
I can't find it. Where's Waldo?
OK, I hired Superman to move the moon and place it beside the Ring Nebula and placed it in proximity to a large crater so you can see how the size of the Ring Nebula compares to it.
Now you don't have to compare one image to another.
Also, I don't think Waldo can crawl through this ring.
And I think that this gives everyone a very good visual representation of the size difference.
DickC
Loc: NE Washington state
Very nice photos, thanks for sharing!!
SonnyE
Loc: Communist California, USA
Ah-Ha! I see Waldo!
Looks like Pac-Man Moon is about to chomp a blue donut.
SonnyE wrote:
Ah-Ha! I see Waldo!
Looks like Pac-Man Moon is about to chomp a blue donut.
You could look at it that way!
That's impressive Jim , I saw this on the hubble site newsletter and is truly amazing , it shines light on the galaxies that lie beyond this "GEM" of a nebula. Such a small piece of sky , holds so many treasures. That was a good choice throwing a quarter moon in the comparison . I want a 640,000 pixel camera. KUDOS my friend.
As my 7 year old granddaughter said to me a few days ago, "cool dude"
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