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"Nightfall" by Isaac Asimov (you can hear the story here on escapepod, if you need it) postulates a planet in a multi-sun system. The orbital mechanics of the 6 suns result in all of the sides of the planet being illuminated all of the time but for one short period of a single 'day', at the 5 big suns just happen to align on one side of the planet with the dimmest one blackened out by the single moon opposite to them, leaving it to rotate a full time with a considerable (half) of the planet not illuminated. This event happens all ca. 2050 years, resulting in massive fear of the dark and crumbling society.

Now... How would this Hexa-star system have to be set up, assuming there is no other planet or moon?

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    $\begingroup$ This paper seems to describe what you want: arxiv.org/ftp/arxiv/papers/1407/1407.4895.pdf I'm not going to turn that into an answer since I'd be copy-pasting what's in the paper into an answer. $\endgroup$ – Green Jun 13 '18 at 13:09
  • $\begingroup$ @Green sadly, it does only describe a short stable period, as evident in the drifting apart of the two suns, and no check was done if the period of 2049 years was kept... but a good read nontheless (and oddly enough also the one that was linked to in the very short lived link only answer) $\endgroup$ – Trish Jun 13 '18 at 13:15
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    $\begingroup$ @Trish everything I read about complicated solar systems like this is that they aren't ever stable over geological time scales. There's just too much sensitivity to initial conditions that add up over time. $\endgroup$ – Green Jun 13 '18 at 14:04
  • $\begingroup$ I added the PDF because I believe it answers your question and not everyone can see deleted answers. $\endgroup$ – Green Jun 13 '18 at 14:04
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Designing a star system that has a planet with perpetual sunlight for thousands of years at a time is an almost impossible problem. Therefore I would say:

This looks like a job for Sean Raymond of the PlanetPlanet website:

And in fact he has discussed the many, many problems with designing a Kalgash system that will work as in the story, in some posts this year.

[https://planetplanet.net/2018/02/02/real-life-sci-fi-world-11-kalgash-a-planet-in-permanent-daytime-from-asimovs-nightfall/1

https://planetplanet.net/2018/03/21/asimov-kalgash-take2/2

Sean decided that the Kalgash system as described in the novel wouldn't provide the necessary length of time between darkness.

so he designed a different type of solar system than in the story and novel, in order to get one where a planet could have eternal light.

And I suppose that his answers are the best you can expect to get.

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  • $\begingroup$ Thanks for the plug! And I'm happy to answer any questions about the systems I set up if anyone is interested. $\endgroup$ – Sean Raymond Jun 14 '18 at 7:40
  • $\begingroup$ you might also pick up Green's comment to add this PDF with a short resumee, because together with Sean's texts, it illuminates that Klgash might be possible as a Hexa-star system with 2 doubles and 2 singles and two planets around the single, but possibly not on the time between nightfalls as described in the story. $\endgroup$ – Trish Jun 14 '18 at 8:56

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