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The Sun & Moon Cycles
Posted: 25 August 2013 09:04 PM   [ Ignore ]   [ # 46 ]  
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Ah, Maryanne, for the file size increase many thanks. The star charts of Aughra were coming out small and blurry. If to scale they were, this would have been a much greater problem. Alas, they are more for visual reference, and feature no moons, only the suns and Thra, yet now Aughra can post them with greater clarity. And with that note, repost the latest I shall . . .


First, Nam’s model (most plausible):

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Posted: 25 August 2013 09:24 PM   [ Ignore ]   [ # 47 ]  
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Other plausible models which meet all criteria for a day/night cycle of some kind and a Great Conjunction where the three suns align one within the other as is mandated by the cannon.

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Posted: 25 August 2013 09:25 PM   [ Ignore ]   [ # 48 ]  
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In this model, Thra and the Dying Sun move in tandem, with the Dying Sun inching further away each trine in its orbit, until it loops back around 1,000 trine later, to align in the Great Conjunction with Thra.

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Posted: 27 August 2013 04:37 PM   [ Ignore ]   [ # 49 ]  
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Thanks Maryanne!

Looks up “Wow… that’s some sky.”

Maryanne Pittman - 25 August 2013 11:44 AM

Hello Chall,


This question relates to the terrific thread (IMHO) here regarding the sun and moon cycles. I’ve merged them together; hope you don’t mind. There are some great posts already here to read through. This is a really wonderful topic to continue to develop.


Best regards,
Maryanne


P.S. It’s just sooooo tempting to end this by saying “look upwards and share the wonders….” Will you all forgive me for doing it?


tongue rolleye

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Posted: 27 August 2013 05:23 PM   [ Ignore ]   [ # 50 ]  
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Hmm, in Nam’s model, the Dying Sun is something special, ominous.

A leviathan celestial spirit that only shows up in times of great import. Very interesting.

Thank you for this thread, it’s been most illuminating.

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Posted: 14 September 2013 08:33 PM   [ Ignore ]   [ # 51 ]  
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Great Sun = Yellow
Rose Sun = Pink
Dying Sun = Dark Blue
Thra = Green
Axis = Orange
Orbits= Light Blue

This is how the Sun’s and Thra align at the Great Conjunction. The Great Sun is the center of the solar system. The Rose Sun orbits the Great Sun. On a “Day of the Rose Sun” the Rose Sun eclipses the Great Sun. This would be more like a seasonal event, happening for a month straight for a full eclipse. But a day within that time would be a “Day of the Rose Sun” (Gelfling Gathering. pdf).  The idea of perpetual daylight can be fixed by the tilt of Thra’s axis and the Dying Sun and it’s lack of light. The Dying Sun would be the “moon”. This would have a monthy orbit around Thra. The Dying Sun then must be smaller than Thra, but when it is that close it looks larger from Thra. As far as Aughra’s angle of eternity… I suppose one could give her the excuse of depicting Thra and the Sun’s as they are seen from Thra. In example: Astrology vs Astronomy. She depicted it from the Astrological, how they would appear from within Thra’s “Celestial Dome”

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Posted: 02 October 2013 04:33 PM   [ Ignore ]   [ # 52 ]  
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This may have already been addressed, but I took a class once that said it was possible for a planet to orbit two - or, in this case three - suns in a figure eight pattern.  Does anyone know if it is possible for this scenario:
The Dying Sun orbits the Rose Sun.
Both the Rose Sun and the Dying Sun orbit the Greater Sun together.
Thra orbits between the Greater Sun and the other pair in a figure eight pattern that is always moving around the Greater Sun orbit.

Does that make sense?
If so, is it possible?

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Posted: 14 November 2013 12:11 AM   [ Ignore ]   [ # 53 ]  
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And the orbit and angle of a planet determines the weather, right? What about that?

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Posted: 22 November 2013 09:10 AM   [ Ignore ]   [ # 54 ]  
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Maryanne Pittman - 25 August 2013 11:44 AM

 


P.S. It’s just sooooo tempting to end this by saying “look upwards and share the wonders….” Will you all forgive me for doing it?


tongue rolleye

i know this isn’t a recent post, but i only just spotted it. high 4!  and also, hell yeah!

 

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Posted: 20 April 2016 05:47 AM   [ Ignore ]   [ # 55 ]  
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Thank you all for a most interesting thread.  I have been considering this question ever since the films.

There are two problems with most possible two and three star systems.  Firstly there is the question of the relative sizes of the three suns, as viewed from Thra, and secondly there is the question of the direction of their relative movement.

Consider the first question: at the moment of the Great Conjunction all three suns and Thra are lined up perfectly and in order of size.  ie the sun nearest to Thra is smallest and the sun farthest is largest, with sufficient difference in angular size as to appear like an eye.

For this to be possible Thra must be on an orbit outside all three.  If Thra were orbiting its closest sun - the Dying Sun - then, firstly, it would have to be so close to that sun as to be tidally locked to it (so that sun would not move in the sky), much like planet Mercury is to our sun, and secondly - being closest to that sun - it would appear huge relative to the other two and easily big enough to eclipse them.  Our own moon, for example, is tiny compared to the sun but being close to us appears exactly the same size such that it totally covers the sun during eclipses.  The only way to get the ‘eyeball effect’ is for all three suns to be similarly distant from Thra ie it orbits all three of them.

Then there is the question of their relative motion.  Seen from Thra directly up through the roof of the Crystal Chamber, the three suns do not approach each other in a straight line: they approach at 120 degree angles from opposite corners of an equilateral triangle.  Since the Greater Sun is clearly the one around which both the other suns and Thra are orbiting then it would move across the sky more or less perpendicular to Thra’s own axis of revolution.  Our own sun appears to move across the sky because the Earth is spinning on its axis.  Thra must be similarly spinning because it has day and night.

Any objects orbiting a massive body (such as the Greater Sun) would normally tend to be on the plane of its ecliptic, having formed out of its protoplanetary dust cloud.  Since both of the smaller suns appear to cross the path of the Greater Sun, from opposite directions, we must conclude that either both of them or Planet Thra itself are on highly eccentric orbits inclined at 60 degrees to the solar ecliptic.  It may also be that Thra’s axis of rotaton is highly tipped so at least one of the lesser suns might be on Thra’s ecliptic plane.

We have to set aside concerns here about the temperature differences on Thra as it orbits three suns, and questions as to the frequency of conjunctions.  Consider how frequently Planet Venus has its transits in front of the sun, if Venus is to be proxy to one of the lesser suns.  Quite clearly both the Rose Sun and the Dying Sun must be emitting almost negligible heat otherwise they would be causing massive variations in temperature on the surface of Thra.  We need to assume that Thra is on an earth-like orbit around the Greater Sun in order to give it the stability for life to exist.

A better model, I think, is to assume that both the lesser suns are effectively residual cores of dead novae, but still glowing brightly enough to be visible in the daytime sky, and that both are on highly eccentric, highly elongated, highly inclined orbits around the Greater Sun that periodically bring them inside the orbit of Thra.  An orbit is effectively an oval shape and will be around a massive object close to one end of that oval.  This would place them out in the void for most of their orbits but have them each occasionally rushing through the inner solar system like comets.  If their orbits were long enough and both prime number periods then opportunities for both the cross the path of the Greater Sun simultaneously would be much rarer and possible within the thousand-year period of the Great Conjunction.  It would naturally follow that such a conjunction would be accompanied with massive gravitational disruption that might even pull the planet out of its orbit and send it spiralling in to the Greater Sun.  If the movement of these suns around the Greater Sun were, at that point, faster than that of Thra’s rotation on its axis, then they would appear (on the surface of Thra) to be travelling in the opposite direction to the Greater Sun.  Mar’s moon phobos thus appears to be rotating in the wrong direction around Mars but this is simply because it orbits Mars faster than Mars is rotating.  That would explain the three suns converging and crossing each other within a triangle, I think.

The big objection to such an arrangement, although that is the only arrangement that I can see might work, is that such elongated eccentric inclined orbits are, by nature, highly unstable.  We must assume that the lesser suns were both ‘interstellar wanderers’ that were accidentally captured by the Greater Sun.  There will be a strong tendency, at the far extremity of their orbits, for these suns to escape the gravity of the Greater Sun and return to wandering the galaxy.  There must, then, be some other agency at work keeping such orbits as stable.  Hmm.  Something like a magic floating crystal might just do the trick.

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