Starship Asterisk*

[quote="Guest"]I'm curious about why the Antarctic analemma isn't smooth. By that I mean some of the dimmer spot ( I presume a cloudy day) are not on what is otherwise a smooth curve but offset a bit to the right. Does the refractive index of a cloudy day offset the position?[/quote]
I suspect the camera wasn't perfectly stable.

I'm curious about why the Antarctic analemma isn't smooth. By that I mean some of the dimmer spot ( I presume a cloudy day) are not on what is otherwise a smooth curve but offset a bit to the right. Does the refractive index of a cloudy day offset the position?

[quote="Cousin Ricky"][quote="Nitpicker"]Unless we define top equivalent to North and bottom equivalent to South.[/quote]

I would consider that inappropriate in a scene that includes a terrestrial horizon, unless the camera is pointed straight up.[/quote]

I'm not so sure about that, in general. From some parts of Earth at some times of day, the analemma appears on its side. It is worthwhile to describe it relative to celestial north. And from the southern hemisphere, when observing the ecliptic, one typically faces more northward than southward -- when facing north, celestial north is down and celestial south is up.

[quote="Nitpicker"]Unless we define top equivalent to North and bottom equivalent to South.[/quote]

I would consider that inappropriate in a scene that includes a terrestrial horizon, unless the camera is pointed straight up.

Thanks for the further info Neufer

My Aunt Alemma came to visit once....she used to do Figure 8s too... :lol2:

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[quote="Cousin Ricky"][quote="APOD Robot"]At the [url=http://en.wikipedia.org/wiki/Solstice]Winter Solstice[/url] in Earth's northern hemisphere, the Sun appears at the bottom of the analemma.[/quote]

Doesn't the Sun appear at the bottom at winter solstice in [i]either[/i] hemisphere (unless you are within one of the polar circles, in which it doesn't appear at all)?[/quote]

Aye, but the time of Winter Solstice in the North, is the time of Summer Solstice in the South, from where the Sun appears at the top of the analemma. Unless we define top equivalent to North and bottom equivalent to South. The terms top and bottom become most confusing in equatorial zones.

[quote="APOD Robot"]At the [url=http://en.wikipedia.org/wiki/Solstice]Winter Solstice[/url] in Earth's northern hemisphere, the Sun appears at the bottom of the analemma.[/quote]

Doesn't the Sun appear at the bottom at winter solstice in [i]either[/i] hemisphere (unless you are within one of the polar circles, in which it doesn't appear at all)?

[float=right][img3="[b][color=#0000FF]Analemma plotted as seen at noon GMT from the Royal Observatory,
Greenwich (latitude 51.48° north, longitude 0.0015° west).
φ line at 38.12° [= 90°- 51.48°][/color][/b]"]https://upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Analemma_Earth.png/1024px-Analemma_Earth.png[/img3][/float][quote="BMAONE23"][quote="Guest"]

If you were at the north or south pole, would you see just a figure 0 or an inverted U shape?[/quote]
It would look similar to [url=http://apod.nasa.gov/apod/ap150923.html]this Antarctic Analemma[/url] just different dates
[/quote]
The North Pole would see the full bow
[b][u]above[/u][/b] the equinox φ line :arrow:

The South Pole would see the U shape
[b][u]below[/u][/b] the equinox φ line ([u]inverted[/u]) :arrow:

[quote="Guest"]If you were at the north or south pole, would you see just a figure 0 or an inverted U shape?[/quote]
It would look similar to this Antarctic Analemma just different dates
http://apod.nasa.gov/apod/ap150923.html

If you were at the north or south pole, would you see just a figure 0 or an inverted U shape?

I'm bored with analemmass. Maybe some year the Sun could do a figure 7 or figure 9 instead? Just for variety?

Nice that it happened on a nice day....

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[url=http://apod.nasa.gov/apod/ap160822.html][img]http://apod.nasa.gov/apod/calendar/S_160822.jpg[/img] [size=150]Tutulemma: Solar Eclipse Analemma[/size][/url]

[b] Explanation: [/b] If you went outside at exactly the same time every day and took a picture that included the Sun, how would the Sun's position change? With [url=http://en.wikipedia.org/wiki/Image:Train_wreck_at_Montparnasse_1895.jpg]great planning[/url] and effort, such a [url=http://www.youtube.com/watch?v=cLNqaYFqvoA]series of images[/url] can be taken. The figure-8 path [url=https://www.nasa.gov/sun]the Sun[/url] follows over [url=https://pantherfile.uwm.edu/kahl/www/Images/Weather/Other/analemma.html]the course of a year[/url] is called an [url=http://en.wikipedia.org/wiki/Analemma]analemma[/url]. At the [url=http://en.wikipedia.org/wiki/Solstice]Winter Solstice[/url] in Earth's northern hemisphere, the Sun appears at the bottom of the analemma. [url=http://www.youtube.com/watch?v=QmHwyQwn0Sg]Analemma[/url]s created from different latitudes appear at least slightly different, as well as [url=http://www.youtube.com/watch?v=IhqzW97_47w]analemmas[/url] created at a different time each day. With even greater planning and effort, the series can include a [url=http://apod.nasa.gov/apod/ap050407.html]total eclipse of the Sun[/url] as one of the images. Pictured is such a total solar eclipse [url=http://apod.nasa.gov/apod/ap131014.html]analemma[/url] or Tutulemma - a term coined by the photographers based on the [url=http://www.bulutsu.org/ggg/gecmis.php]Turkish[/url] word for eclipse. The [url=http://www.spaceweather.com/glossary/tutulemma.htm]featured composite image[/url] sequence was recorded from [url=http://en.wikipedia.org/wiki/Turkey]Turkey[/url] starting in 2005. The base image for the sequence is from the [url=http://apod.nasa.gov/apod/ap060404.html]total phase[/url] of a solar eclipse as viewed from [url=http://en.wikipedia.org/wiki/Side%2C_Turkey]Side[/url], Turkey on 2006 March 29. Venus was also visible during totality, toward the lower right. If you want to create your own USA-based tutulemma ending at [url=http://apod.nasa.gov/apod/ap160821.html]next August's total solar eclipse[/url], now would be good time to start.

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