APOD: Frosted Leaf Orion (2010 Nov 17)

[Ann]

The very red color of the leaf suggests a maple. Of course several other leaves become very red, too, like cherry trees and other prunus trees, but they have single leaves, not leaves with many lobes. Horse chestnuts, to my knowledge, never become red.

Ann

[Translatorastronomer]

Due to the color according to the time of year, the number of protusions and the texture of the leaf, it seems fairly reasonable to say that it is a leaf of red cutleaf japanese maple (Acer japonicus). On the other hand, the japanese maple family is pretty extensive and It is difficult to determine what is our actual leaf's exact species and genus without having it at hand.

hope this helps

[Mpwrmnt]

Well! I thought I knew what a Japanese Maple looked like... and it WASN'T that! So I started looking up images for every tree that different people have suggested here, in order to form my own opinion. Gradually, I narrowed it down to... a Japanese Maple! However, in the process, I discovered that there are literally HUNDREDS of different kinds of Japanese Maples! So my best guess is the one they call Ohmomiji (or Oomomiji) which is Acer amoenum (which some people classify as part of Acer palmatum).

The image I found that I think most closely resembles our frosty leaf is, unfortunately, not identified any more specifically than "Japanese Maple."
It is at http://www.flickriver.com/photos/darren ... 960130047/.
Other similar images can be found at
http://www005.upp.so-net.ne.jp/goostake/GOO/XOOMMJ.HTM and http://www.engei.net/Browse.asp?ID=53963.
In addition, these two pages have collections within which are several good candidates: http://ganshuku.sblo.jp/index-4.html and
http://homepage2.nifty.com/chigyoraku/E-repo12.html.

[neufer]

I'm not sure about the leaf. It may be a Maple! I have Maples; but they have 5 lobes.

Click to view full size image

Click to view full size image

[EK]

Not a clue about the leaf... to me it's a "red leaf" The "meteor" though looks suspiciously like an Iridium flare. Relatively characteristic fade-in/fade-out and traveling roughly North/South given the wide angle distortion.

[Willie]

The leaf looks like a momiji to me - the kind that's green in summer, but goes purple in autumn (right now in Japan, in fact!). Someone said a Horse chestnut because it has 7 lobes, not five, but some momiji trees have 7 lobes.

[Anonimo Veneziano]

E' sicuramente la foglia di un ippocastano!

Per Google Translate

• It's definitely the leaf of a chestnut tree!

[Ann]

I googled "momiji" and found this:

Click to view full size image

Pretty, isn't it? But I don't know if the leaves have the right shape. They certainly have the right shade - of red, that is!

Ann

P.S. Okay, I found a truly huge closeup of momiji leaves. The picture is so big that I will only post it as a link. What do you think, is the frosted leaf in APOD November 17, 2010 a momiji leaf?

http://www.ualberta.ca/~ptjc/JLPT2007/Momiji.jpg

[RJN]

http://www.metafilter.com/97789/Frosted-Leaf-Orion

[NoelC]

Why does Orions belt look so small? Sometimes it fills 1/3 of the sky!

I can't say it ever seems to fill 1/3 of the sky when I've looked, but it could have to do with your perspective. For example, if you were looking up and were surrounded by tall, thick trees, the part of the sky you could see might be dominated by Orion.

As far as why it looks small, it's a wide angle shot, with very close things in the foreground dominating the image, and more distant things - e.g., the stars in the sky - seeming all the more distant. Wide angle lenses can make an image appear that way.

-Noel

[Chris Peterson]

Why does Orions belt look so small? Sometimes it fills 1/3 of the sky!

I can't say it ever seems to fill 1/3 of the sky when I've looked, but it could have to do with your perspective. For example, if you were looking up and were surrounded by tall, thick trees, the part of the sky you could see might be dominated by Orion.

As far as why it looks small, it's a wide angle shot, with very close things in the foreground dominating the image, and more distant things - e.g., the stars in the sky - seeming all the more distant. Wide angle lenses can make an image appear that way.

Right. The belt spans less than 3°- a bit over five lunar diameters. It's always that size, regardless of position in the sky. As you note, how wide 3° seems in an image depends on the field of view, which is determined in part by the choice of lens.

[Mpwrmnt]

Will the fact be revealed soon?

Ok, Bob & Jerry (or WHOEVER's moderating this discussion!) - How long are you going to keep us in suspense? I think 6 days is long enough! If we haven't figured it out by now, we're probably not going to!

DO tell!

[Ann]

I googled "momiji tree wiki" and got the following article from http://en.wikipedia.org/wiki/Acer_palmatum.

Please note the following passages:

Acer palmatum includes hundreds of named cultivars with countless forms, colors, leaf types, sizes, and preferred growing conditions.
...
Cultivars are chosen for phenotypical aspects such as leaf shape and size (shallowly to deeply lobed, some also palmately compound), leaf colour (ranging from chartreuse through dark green or from red to dark purple, others variegated with various patterns of white and pink)

I think we can be pretty sure that the frosted leaf in question is indeed from the family of Acer palmatum, a kind of maple from Japan. As for what sort of cultivar it is, I doubt that Robert and Jerry can tell us.

Ann

[Céline Richard]

Hi everybody

"Frosted Leaf Orion" is such a wonderful picture! It sounds so magical !!! Great, great picture

Leibniz, the philosopher, thought that the Universe was made of tiny components (which Leibniz called "monades", but this is in french, because my translator doesn't understands... ). Each tiny component, each "monade", would conceal the whole Universe! However, humans could not see the whole Universe inside each "monade". According to Leibniz, only God could redeploy the whole Universe from each "monade".
Can't you see our Universe inside the "APOD-Frozen Leaf" ? Frozen dewdrops sparkle so much, that we can compare it to both the starry night and Orion. This misterious frozen leaf conceals our Universe, or...
It might conceals a new little universe

Have a very nice day!

Céline

[nsd20463]

Something else interesting (to me) is the chromatic aberration visible in the stars in the edge of the photo. The further from the center of the photo and lens, the more the colors spread, with blues bending the most and thus appearing closer to the center than reds.

[Céline Richard]

Hi

Something else interesting (to me) is the chromatic aberration visible in the stars in the edge of the photo.

D
o you call chromatic aberration the vivid blue, as well as the vivid red, in stars, we can see in the picture?

The further from the center of the photo and lens, the more the colors spread, with blues bending the most and thus appearing closer to the center than reds.

The blue stars appear closer to the center than the reds one, indeed... Thank you because i thought it was due to a difference of composition of the different stars.
However, i would be happy to understand better the situation: why the further from the center of the photo and lens, the more the colors spread?
What do you mean by "bending"? How the beautiful blue color can being "bending" more than the red color?

Have a very good day!

Céline

[nsd20463]

I mean how the stars which ought to be points of light are instead little rainbows, with the blue end facing the center of the photo, and the red towards the outside.

To see it, look in the full photo at the four brightest stars below the meteor, or the bright one next to the tree along the right edge.

The chromatic aberration is caused by the camera's lens. Lenses bend the path of light by diffraction. The amount of bend depends on the frequency of the light. Lower frequencies (red) bend less then higher (blue) frequencies. At the very center of the photo, the light is not bent on average[1]. At the edges nearly all the light arriving at that point of the photo is being bent by the lens. That is why the CA is more visible at the edges.

Lens do try and correct for CA, but nothing is perfect, wide angle lenses like the one used here have a harder time with CA, and stars are really point-like sources on a black background.

http://www.dpreview.com/learn/?/Glossar ... ion_01.htm
has a nice diagram at the top. Also wikipedia has a page about CA.

[1] At the very center of the photo, light arrives in symmetrical paths from all areas of the lens. So even though the red light which came from the outer part of the lens is not quite focused, and the blue is over focused, the result is a smearing of the dot by the thin red and blue rings, which is not easily visible because the red and blue are superimposed.

[Céline Richard]

Hello,

Thank you!!
So we have more blue stars in the center, because the blue light bends more than the red light, because the blue light has a higher frequency... Why don't we see always blue stars? I mean, why in the edge, there is at least one red star?

Now, i understand that we don't see CA a lot, at the edge of the picture, because of diffraction, which spreads the light, instead of focusing it. I guess the more the light is focused, the better we see.
At the center of the image, light is focused, because light comes from symmetrical paths, from all the areas of the lens. This is very interesting, thank you

If i understand well: a perfect lens would suppress Chromatic Aberrations, in order to be able to admire many dot-like stars, from everywhere in the night sky. However, maybe this picture would be less beautiful without CA, because i find colors are beautiful here

I mean how the stars which ought to be points of light are instead little rainbows, with the blue end facing the center of the photo, and the red towards the outside.

In a rainbow, the red is toward the outside, like in the photo, the red stars are more located at the edge, yes...
I am afraid I don’t understand the analogy I know in a rainbow, each drop involves a deflection of light, more or less important, according to the frequency of the light. In a telescope, there is a lens, which involves also a deflection of the light, according to the frequency. If I write true things, so a lens looks like a little drop of water?
Actually, when I put glasses, I could use drops to read better a book, but I need to look far away, while I don’t think water could help me to see further.
I was told a glass windows was a liquid: if I look at it, after a century, I should be able to see the windows has become thicker at the lower than at the upper levels of the windows.
Maybe the fact that glass would be a fluid is the reason why a lens looks like a drop of water, or maybe I am making up science fiction…

Thank you a lot for all your explanations!
Have a very good day,

Céline

[Chris Peterson]

So we have more blue stars in the center, because the blue light bends more than the red light, because the blue light has a higher frequency... Why don't we see always blue stars? I mean, why in the edge, there is at least one red star?

Now, i understand that we don't see CA a lot, at the edge of the picture, because of diffraction, which spreads the light, instead of focusing it. I guess the more the light is focused, the better we see.
At the center of the image, light is focused, because light comes from symmetrical paths, from all the areas of the lens.

Camera lenses (even the best) are of poor optical quality compared with most telescopes. They simply are not designed to capture point sources over a wide field. What is actually going on optically in this image is complex- there are many aberrations.

Most lenses are nearly perfect right on the optical axis, and then the aberrations increase with distance from the center. You can see that here. Spherical aberration, coma, and field curvature all increase towards the edges, which makes the outer stars appear larger, and also gives them a comet-like shape (hence, "coma"). Chromatic aberration comes in two flavors: light of different wavelengths can have different focal planes, or light of different wavelengths can cross the focal plane at different positions. The first causes colored halos around stars, the second causes asymmetric color fringing. Both are present in this image, and the radial distortion at the edges further emphasizes each.

I was told a glass windows was a liquid: if I look at it, after a century, I should be able to see the windows has become thicker at the lower than at the upper levels of the windows.

That's a myth that doesn't seem to ever go away. Glass is not a liquid, it is an amorphous solid. It does not change dimensionally with time. Glass windows don't eventually get thicker at the bottom edges.

[NoelC]

On glass flowing:

http://www.cmog.org/dynamic.aspx?id=294

-Noel

[markseibold]

Beautiful photography of the winter sky and the earth below! I commend Masahiro Miyasaka for this great effort on producing this image.

I designed and built my own home 22 years ago. Planted many trees, several of which were known as Laceleaf, and Palmatum Maples originating from Japan. I miss seeing those trees now as I lost the home in foreclosure a couple years ago after 20 years there. This image by Masahiro brought me back home for a few moments again.

I have spent thousands of hours observing Orion and the M42 nebula through my 10 inch Dobsonian in the winter skies from my homes backyard under relatively dark skies 20 miles east of Portland Oregon. I began making serious skethces thorugh the telescope eyepiece a few years ago after landing a few award winning phgotographs in Astronomy magazine and other online publishing and venues many years before.

However, the sketching has taken over now but I still do an occasional digital time exposure photograph of the night sky with some ground effects.

I hope to see more details here about how Masuhiro achieved this photo.

Thank you, -Mark Seibold

[Céline Richard]

Thank you a lot Chris!

That's a myth that doesn't seem to ever go away. Glass is not a liquid, it is an amorphous solid. It does not change dimensionally with time. Glass windows don't eventually get thicker at the bottom edges.

I am so surprised I remember a friend showed me a glass in my university, and told me "see that window, it is thicker near the ground than near the roof!". He told me about some sort of fluid...
So it is an amorphous solid: atoms are not put into a structure, but this is like entropy, i mean atoms are set in desorder (i googled amorphous). There are cristal solid, but glass is an amorphous solid.
If glass doesn't change dimensionally with time, either the window of my university was made of different materials (including glass), either my friend and i couldn't realise the real thickness of the window. It is difficult to see, throw an open window, the thickness of it.

Thank you a lot
Have a very good day!

Céline

[Chris Peterson]

I am so surprised :o I remember a friend showed me a glass in my university, and told me "see that window, it is thicker near the ground than near the roof!". He told me about some sort of fluid...
So it is an amorphous solid: atoms are not put into a structure, but this is like entropy, i mean atoms are set in desorder (i googled amorphous). There are cristal solid, but glass is an amorphous solid.
If glass doesn't change dimensionally with time, either the window of my university was made of different materials (including glass), either my friend and i couldn't realise the real thickness of the window. It is difficult to see, throw an open window, the thickness of it.

Modern window glass is made by pouring it flat on a molten metal surface. But go back more than about 100 years, and window glass was made by spinning large discs. These were thicker at the center than the edges, so window panes were generally wedge shaped. Glazers usually installed the panes with the thick side down, which is one reason for the belief about glass flowing.

Consider telescope mirrors. They are made of glass, and ground to an accuracy of less than the wavelength of light. If windows could change shape at the rate of a millimeter per century or so (as you might guess looking at cathedral windows), how long would it take for a telescope mirror to become deformed by a few tens of nanometers? Answer: not very long. If telescope mirrors changed shape with time, all but the newest professional telescopes would currently be useless. It's a good thing glass is stable!

[Céline Richard]

This is deeply interesting, thank you a lot!

go back more than about 100 years, and window glass was made by spinning large discs. These were thicker at the center than the edges, so window panes were generally wedge shaped.Glazers usually installed the panes with the thick side down, which is one reason for the belief about glass flowing.

It makes sense a lot

Consider telescope mirrors. They are made of glass, and ground to an accuracy of less than the wavelength of light. If windows could change shape at the rate of a millimeter per century or so (as you might guess looking at cathedral windows), how long would it take for a telescope mirror to become deformed by a few tens of nanometers? Answer: not very long. If telescope mirrors changed shape with time, all but the newest professional telescopes would currently be useless. It's a good thing glass is stable!

Actually, you answered better to my questions than what i have expected to understand. With an accuracy of less than the wavelength of light

Have a very good day, thank you,

Céline

[YURI BASIN]

Ricinus communis