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APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 5:05 am
by APOD Robot
Image Analemma 2010

Explanation: Looking back on the year, have you wondered where the Sun was in the sky each day during 2010 at exactly 9am UT? Of course you have. Search no further for the answer! It was somewhere along this celestial figure 8 curve known as an analemma. Recorded from a residential backyard in the small town of Veszprem, Hungary, this composite analemma image consists of 36 separate exposures of the Sun made at 9:00 UT, spaced throughout the year, plus a background image made without a solar filter. The background image was taken on the sunny afternoon of October 9 (13:45 UT). On the left is the photographer's shadow. The positions of the Sun at the 2010 solstice dates are at the upper (June 21) and lower (December 21) extremes of the analemma curve. On the equinox dates (March 20, September 23) the Sun was along the curve half way between the solstices. The tilt of planet Earth's axis and the variation in speed as it moves around its elliptical orbit combine to produce the graceful analemma curve.

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Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 5:15 am
by Beyond
I think the last time i saw this, it was tilted the other way. Well, no matter which way it is, it still looks neat.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 6:34 am
by AZJames
This is one of the best examples I've seen, all done with simple equipment if the shadow image of the photographer is representative. Again, with that assumption, consider the problem of maintaining the orientation of the camera for all exposures over a year's time. Maybe he erected a tent to protect the camera/tripod leaving it set up on his lawn? :)

From the discussion I infer that if the Earth's orbit were a perfect circle the lobes of the analemma would be perfectly symmetrical. Consider the repercussions if Aristotle had made this sort of observation vis-a-vis the 'Perfect Spheres' notion of cosmology.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 7:49 am
by agulesin
One of the best APODs this year from my point of view. In a way it encourages us to try to capture astronomic events on film (sorry, pixels!), encourages us to realise that every day is different to the last ones (even if only the position of the sun!) and also reminds us that things are not just turning simply on their axes, there is a much more delicate balance in everything we take for granted...

Congrats to Tamas, especially for the way he managed to get himself into the frame! :-)

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 10:29 am
by annoymous
I'm confused - how is the photographer's shadow in the picture? And doesn't that look more like a front yard then the backyard?

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 11:30 am
by Phil T, Sweden
If the camera is photographing the Sun in front, how come the shadows in this picture are from right to left ?

Front yard surely: Road, Fireplug ...

Posted: Fri Dec 31, 2010 11:46 am
by RedFishBlueFish
Recorded from a residential backyard
I have always wanted to record an analemma - but have not had the self-discipline to be able to do so. Having started a New Year with a resolution that THIS would be the year, I once got as far as February.

Wonderful.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 11:49 am
by RedFishBlueFish
Phil T, Sweden wrote:If the camera is photographing the Sun in front, how come the shadows in this picture are from right to left ?
... background image was taken on the sunny afternoon of October 9 ...

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 12:11 pm
by lenka
I like this kind of regularity. It reminds me elements. It is also like a craft. Making something with no immediate effect, contemplating the material, collecting things. It is like knitting a sweater, creating patterns symbolizing infinity. Great picture!

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 1:21 pm
by jrjanzen
Obviously concocted. The shadows in the picture are in a direction NEVER achieved by any of the solar positions on the analemma!

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 1:22 pm
by neufer
beyond wrote:
I think the last time i saw this, it was tilted the other way. Well, no matter which way it is, it still looks neat.
Analemma's lie on the celestial equator with the little loop end pointed towards Polaris (the celestial north pole).

In the northern hemisphere Polaris is
off to the upper left in the morning: and off to the upper right in the afternoon: What APOD lacks is a southern hemisphere analemma with the little loop end pointed
down to the lower left in the morning or down to the lower right in the afternoon.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 1:43 pm
by WildGuruLarry
jrjanzen wrote:Obviously concocted. The shadows in the picture are in a direction NEVER achieved by any of the solar positions on the analemma!
Question: How could you believe that a photo with 36 suns in it could NOT be "obviously concocted"?

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 2:00 pm
by neufer
WildGuruLarry wrote:
jrjanzen wrote:
Obviously concocted. The shadows in the picture are in a direction NEVER achieved by any of the solar positions on the analemma!
Question: How could you believe that a photo with 36 suns in it could NOT be "obviously concocted"?

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 2:15 pm
by Brewer
Wouldn't it be wonderful to see a set of these with a Northern Hemisphere (say 45 degrees north), an equatorial and a Southern Hemisphere versions! Impressive.

And shouldn't one be able to figure out the latitude, north or south, of the photo(s) by the placement of the crossing in relation to the midpoint?
Some fun!

I have always been so impressed with the effort and discipline needed for these! Wonderful!!

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 2:21 pm
by Sweetwater Tom
What is the significance of the cross-over point in the figure-8? When does it occur?

Thanks.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 2:26 pm
by biddie67
Congratulations, Tamas Ladanyi !! An excellent job of precise perserverence !!

I agree with "Brewer" above - what a great project to collect a set of analemmas from 5 positions on the Earth - the North and South poles, 45 degrees North and South and at the Equator for AM, Noon and PM .....

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 2:37 pm
by biddie67
Oh!! And a mighty hoorah of CONGRATULATIONS to Opportunity, et. al., for reaching the Santa Maria Crater!!

And, finally, a Hearty Happy New Year to all !!!!!

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 2:50 pm
by chainsaw
I think a solar analemma makes a good visual image to keep in mind when trying to understand the women in my life. Just when I think things are consistant every day something comes up which demonstrates that I really don't know which direction they're coming from. I'd bet if I had a fixed camera which rendered images of my lovely wife's emotional state each week, I'd come up with an analemma which would give me a much better understanding of what's really going on! I only hope that the little and big ends of it would have nothing to do with latitude: at approximately 42 degrees north I might have to lie a little bit when asked if her butt looked big.:-) Just sayin'...

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 3:21 pm
by Chris Peterson
jrjanzen wrote:Obviously concocted. The shadows in the picture are in a direction NEVER achieved by any of the solar positions on the analemma!
The images of the Sun were collected in the morning. The landscape image was recorded in the afternoon. The latter needed to be done when the Sun wasn't in the field-of-view, or it would have completely ruined the view of the sky.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 4:40 pm
by skippy
These type of pic here make me want to vomit :mrgreen:

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 4:49 pm
by cmflyer
Polaris never changes position from a given point on Earth. But if you create an afternoon analemma it will have a different angle in the picture from a morning analemma, because the camera is facing in different direction. This one was in the morning.
neufer wrote:
beyond wrote:
I think the last time i saw this, it was tilted the other way. Well, no matter which way it is, it still looks neat.
Analemma's lie on the celestial equator with the little loop end pointed towards Polaris (the celestial north pole).

In the northern hemisphere Polaris is
off to the upper left in the morning: and off to the upper right in the afternoon: What APOD lacks is a southern hemisphere analemma with the little loop end pointed
down to the lower left in the morning or down to the lower right in the afternoon.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 5:59 pm
by BMAONE23
neufer wrote:
WildGuruLarry wrote:
jrjanzen wrote:
Obviously concocted. The shadows in the picture are in a direction NEVER achieved by any of the solar positions on the analemma!
Question: How could you believe that a photo with 36 suns in it could NOT be "obviously concocted"?
WOW Neufer,
That picture is just loaded with Asternuts

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 6:08 pm
by dmbeaster
For those interested in the details of the shape of the analemma, this website is great. http://www.analemma.com/Pages/framesPage.html

The shape and positioning of the analemma is a composite of the effects of the earth's tilt and its elliptic orbit, as well as the position on earth and time of day that you record the images. The tilt stretches the image north/south and also introduces some east-west movement of the curve. The elliptic orbit also stretches the image east/west and creates the different sized lobes of the curve. Where you are on earth determines the degree to which the analemma is tilted from vertical.

Other planets (except Mercury an Venus) have their own analemma based on their own unique characteristics of tilt and elliptic orbits.

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 7:18 pm
by neufer
dmbeaster wrote:
Other planets (except Mercury an Venus) have their own analemma based on their own unique characteristics of tilt and elliptic orbits.
http://en.wikipedia.org/wiki/Analemma wrote: <<On Earth, the analemma appears as a figure eight, but on other solar system bodies it may be very different because of the interplay between the tilt of each body's axis and the elliptical shape of its orbit.

In the following list, "day" and "year" refer to the synodic day and sidereal year of the particular body:
  • * Mercury: Because the day is exactly two years long (due to orbital resonance), the method of plotting the sun's position at the same time each day would yield only a single point. However, the equation of time can still be calculated for any time of the year, so an analemma can be graphed with this information. The resulting curve is a nearly straight east-west line.

    * Venus: There are slightly less than two days per year, so it would take several years to accumulate a complete analemma by the usual method. The resulting curve is an ellipse.

    * Mars: teardrop :arrow: :arrow: :arrow: :arrow:

    * Jupiter: ellipse

    * Saturn: technically a figure 8, but the northern loop is so small that it more closely resembles a teardrop

    * Uranus: figure 8

    * Neptune: figure 8

    * Pluto: figure 8 >>
http://en.wikipedia.org/wiki/Anna_Karenina wrote:
Image
Image
<<Anna Karenina (Russian: Анна Каренина) is a novel by the Russian writer Leo Tolstoy, published in serial installments from 1873 to 1877 in the periodical The Russian Messenger. Tolstoy clashed with its editor Mikhail Katkov over issues that arose in the final installment; therefore, the novel's first complete appearance was in book form.

Tolstoy considered Anna Karenina his first true novel, when he came to consider War and Peace to be more than a novel. The character of Anna was likely inspired, in part, by Maria Hartung (1832–1919), the elder daughter of the Russian poet Alexander Pushkin. Soon after meeting her at dinner, Tolstoy began reading Pushkin's prose and once had a fleeting daydream of "a bare exquisite aristocratic elbow", which proved to be the first intimation of Anna's character.

Although Russian critics dismissed the novel on its publication as a "trifling romance of high life", Fyodor Dostoevsky declared it to be "flawless as a work of Art". His opinion was shared by Vladimir Nabokov, who especially admired "the flawless magic of Tolstoy's style", and by William Faulkner, who described the novel as "the best ever written".>
>

Re: APOD: Analemma 2010 (2010 Dec 31)

Posted: Fri Dec 31, 2010 7:55 pm
by raindrop
Please explain why the lower loop of the analemma is longer than the upper one. Since earth is at perihelion in January and moves faster then, the loop closer to the winter solstice should be shorter than the upper near the summer solsticeone. Earth is moving slower when at apehelion in August. This is going to bother me until someone explains it.