Trinary Stars

dmoffett's picture
dmoffett
July 1, 2013 - 11:31pm

Trinary Star System? Someone please tell me how big one of these would have to be? And would exploring one of them be a good campain/adventure hook. Will you find the Twelve Colonies of Kobol in such a system or a bunch of gas giants and useless dusty rocks? Would I develope wrinkles faster with all these Extra UV rays? LOL Has anyone made any hard rules about designing such a system?

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jedion357's picture
jedion357
July 2, 2013 - 4:54am
I'm not the local rocket scientist so I won't try to comment on the science, however David Weber famously used a IIRC a binary star system as the home system of the main hero in the Honor Harrington series. However that system was not the stage for much of the action early on in the series so its hard to point to a specific book that will give you a good view of that star system. It did have 3 inhabitted planets with the capitol planet being in the "sweet spot" around the system primary, a second planet with really wild weather and a lower population a little further out and the third inhabitted planet with really deep cold (11 month winter) and then a really nice summer orbiting the "distant companion star"

I've toyed with the idea of a trinary system of a primary and a close companion where the close companion orbits almost touching the primary. Then planets orbit both of these stars but we would be talking about some bigger orbits. Finally there would be a distant companion which may or may not have something orbiting it.

One of the things that i toyed with in such a system was that the local population might decide that with so much solar radiation bouncing around the system that solar sails might have more merit and that they may have developed the tech to a higher degree than we usually imagine and that they make natural borm navigators because they spend so much time thinking about the 3d relationships of objects in space to wring the very last bit of propulsion out of their solar sail systems.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Ascent's picture
Ascent
July 2, 2013 - 5:57am
If they were "almost touching," one would strip the other, and the closer they are, the faster and more violent the process.
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OnceFarOff's picture
OnceFarOff
July 2, 2013 - 7:09am
The Alternity game system has a very interesting trinary system called Lucullus. There are two primaries in close proximity, and then a third in a further orbit. 


OnceFarOff's picture
OnceFarOff
July 2, 2013 - 7:14am
And the system is FULL of plot hooks. The Campaign Guide starts off with "Of all the systems inthe Verge, Lucullus is the one they would most like to forget." I've been repurposing a lot of Alternity stuff for my campaign setting. You might get some good ideas from the campaign guide.

dmoffett's picture
dmoffett
July 9, 2013 - 11:22am

Okay, So not really any Hard fast rules to make my own then?

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TerlObar's picture
TerlObar
July 9, 2013 - 2:50pm
Not really.  The real trick is coming up with something that is dynamically stable.  Of course that is only if you want it completely realistic.  Some things to keep in mind.

1) If you want planets orbiting the individual stars of a (relatively) close pair  They have to be close to the star they are orbiting.  IIRC, the numbers are no more than 1/4 the distance between the two stars away from the star the planet is orbiting. 

2) In a three star system you'll have a close(r) pair and then the third stard will be orbiting those two as if a single object.

3) You could have planets orbiting outside the pair but inside the third star's orbit.  For those, item 1 still applies but you now measure the distances between the center of the pair and the third star.

4) For planets orbiting the pair, you can't have them in too close as close interactions with one or more of the stars in the pair will disrupt its orbit fairly quickly

5) While it's possible to have planets orbiting outside all 3 stars, it's not very likely unless they are all fairly close together.

I always check my systems using n-body simulations to run them through millions of years of gravitational interactions (yeah for modern computers) to make sure they are stable as well.  But that's fairly one-off and easy for me as I've got the simulation software lying around (having had to write it in school).
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thespiritcoyote's picture
thespiritcoyote
July 31, 2013 - 2:08pm

There is no official verification for this question to be answered by, and speculation is largely dependent on your preferred cosmology.
Just two paradigms being compared for example; If the universe is a gravitationally bound 3d liquid-crystal lattice as imagined by Einstein's math, then the result is a bit different than if the universe is an electrically charged miasma of neural-networked plasma vortices... either way; metaphysically it seems this indicates imagination and fantasy rule the potentiality of the possible.


Generally speaking, the idea is that a distant star would be more likely than a close pair to have a stable world over 100s of millions earth years, but... with foreign seeding of life being a vastly more prolific option in the SF context, this drastically changes timetables assumed by observations of our singular example.
In the Frontier, for example, it is quite believable to assume 3million years of stability can easily result in an independent race, that was once just a smart pet left behind by a dying empire.

OTOH, it shouldn't be overlooked that we could just be wrong about the time it takes naturally... especially under vastly different circumstances. What changes to the time table would occur if there had been less extinctions, or more, or less large ones but more frequent smaller ones... it quickly becomes purely speculative.


Until recently it had been a consensus of rational confidence that planets would not even be existent in multi star systems... but much of our classical astronomy and astrophysics has failed to account (in preferably simple equations) for a quickly growing number of "unexpected phenomenon" in recent decades...

Today, I can quickly recall about a dozen binary systems with calculated exoplanets, about a third are in some measure "confirmed" to exist... and it is possible my estimate is a few years out dated.
Furthermore, there is at least one trinary candidate that was being looked at recently.


My short answer is, yes.

Life could be supported in systems with multiple stars... especially if that life is very young, or non-native...

Oh humans!! Innocent We discover a galactic community filled with multiple species of aliens, and the first thing we think about is "how can we have sex with them?".
~ anymoose, somewhere on the net...

so...
if you square a square it becomes a cube...
if you square a cube does it become an octoid?

thespiritcoyote's picture
thespiritcoyote
July 31, 2013 - 2:30pm

...I suppose it deserves noting; the larger the variance we might discover from our one known example, the more the consensus has to change about what is known to be possible.


Seasons around even a Yellow-Red binary are going to be wild by our standards, but still potentially sustainable... worrying about increased aging would only be of concern if the planet of interest has not developed a balance of appropriately increased protective shielding... or if for some reason the exploration/colonizing vessel is inadequately equipped for the task.

Imagine this as a trinary... or as three charged particles in a triple helix, dragging along clumps of wet dust... some of those dust clumps saturated enough to support biomes of microscopic life... life that fuels off the ambient triple helix energy of the parent system, and balances into a self sustaining cellular colony... an alien planet, born of alien DNA structures, developed from alien energy patterns.

Yes, every system encountered is worth exploring... evoking as much wondrous interest as every beach, mountain, or previously uncharted waterfall... don't underestimate the awe of the mundane, or the worthiness of even the simplest of uncommon phenomenon.

A Nice Example
How close were you trying to get?
Half a light year? A few thousand AU?
Inside the "inner" system? Less than half a light hour?

One more thing to think about...
Titan's Lakes
...life will find a way, that's it's job.
Oh humans!! Innocent We discover a galactic community filled with multiple species of aliens, and the first thing we think about is "how can we have sex with them?".
~ anymoose, somewhere on the net...

so...
if you square a square it becomes a cube...
if you square a cube does it become an octoid?

bossmoss's picture
bossmoss
January 30, 2014 - 12:43am
I was reading the latest information about exoplanets, and I noticed that there are now several confirmed trinary stars with planets, and at least one quadrinary system with planets!

In a binary system, the planets sometimes orbit only one star.  In other systems, they orbit both stars.  I can only imagine how complicated things get in a trinary or quadrinary system!

jedion357's picture
jedion357
January 30, 2014 - 4:28am
bossmoss wrote:
I was reading the latest information about exoplanets, and I noticed that there are now several confirmed trinary stars with planets, and at least one quadrinary system with planets!

In a binary system, the planets sometimes orbit only one star.  In other systems, they orbit both stars.  I can only imagine how complicated things get in a trinary or quadrinary system!


David Weber's famous sci fi setting has a star nation of a trinary system with each star having a planet in the habitable zone. capitol planet is truly Goldielocks with the other two having interesting weather due to circumstances. Two of the planets are easier to shuttle inbetween while the third is out with the distant companion.

I've often wondered that a race evolving in such a system wouldn't find solar sails ecomnomical for space exploration, solar sail needs pressure from solar wind to move craft and with 3 sources of solar wind there should be the ability to "tack" and sail against the wind as it were, sure its not fast and KHs ion and atomic tech would blow this away but solar sails would democratize space with everyone having their own sail craft.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

bossmoss's picture
bossmoss
January 31, 2014 - 3:28am
Maybe they would not even develop other kinds of travel, and would only use solar sails, at least until they meet other species and are exposed to new ideas...

jedion357's picture
jedion357
January 31, 2014 - 4:45am
bossmoss wrote:
Maybe they would not even develop other kinds of travel, and would only use solar sails, at least until they meet other species and are exposed to new ideas...
Solar sails and chem rockets to get into orbit. Sail vessels might have limited rockets for emergency maneuvers much like small sail vessels have a motor to get out of harbor in the real world.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

bossmoss's picture
bossmoss
January 31, 2014 - 12:34pm
Makes sense.

Blankbeard's picture
Blankbeard
January 31, 2014 - 2:51pm
Tacking with a solar sail.

Alpha Centauri A and B have a closest approach of around 11 AU, a bit farther than Saturn is from the sun. They have a quite eccentric orbit so I'm not sure if the same would hold true if they had a circular orbit but B has a planet and it is thought that both stars could have potential planets in their habitable zones.

I did a bit of calculation and you can apparently produce a stable orbit of only about 2 million km for two stars each the size of the sun. Much closer than that and they start stealing gas from each other and that's obviously not stable. I can't say that a habitable planet would be stable at say 1.5 AU but it might be. ORSA ends up throwing them out of the system but I think that's because I don't really know how to set up a stable system.

A planet like this would see the pair as two suns about one diameter apart. About every 5 hours the two stars would seem to merge and then move apart for the next five hours. If there was another close companion, the planet would probably lack true night part of the year. I didn't run the numbers but I think even a red dwarf in the Alpha Centauri AB orbit would be brighter than the moon.

Following Alpha Centauri, you could set up another star or pair as long as you keep them farther away than about 20 AU and have a reasonable looking multiple star system.

Just stick with stars the size of the sun or smaller. If you want an exotic star like a white dwarf or neutron star, you probably should stick it pretty far away, hundreds or thousands of AU.

I'm not an astrophysicist but this seems possible.

bossmoss's picture
bossmoss
February 1, 2014 - 2:46am
Hmm, sure.  I think that sounds good.