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An interesting binary system (LBB6)

Fritz_Brown

Super Moderator
I'm looking for some ideas. I have been working on my generated sectors, and have begun to look at some of the details. One system is a binary K0 V, with a M dwarf orbiting it in the habitable zone. There is a very decent satellite around a SGG in orbit 0 of the dwarf - so, within the habitable zone of the primary! I found a calculator online to give me the orbital periods (using the numbers for mass and distances in LBB6).

- The M dwarf has an orbital period of a touch over 37 weeks (call it 9 months).
- The SGG has an orbital period around the dwarf of almost 4 1/2 weeks.
- The moon [C660545-6] has a period around the SGG (at 510,000km) of about a week and a half.

So, the moon goes 'round the SGG, which goes 'round the dwarf, which goes 'round the Orange sub-giant. I assume the SGG will not block the dwarf from visibility when the moon is on the far side of it. I also assume the SGG will transit from the far edge of the habitable zone to the near edge as it dances about the dwarf.

What sort of funky day/night cycle will this moon have?
Will it be tidally locked to the SGG? I hope not.
I'm thinking the seasons would be pretty wild, assuming a slightly eccentric orbit (a normal one, iow) - week of winter, week of spring, week of summer, week of fall, but with weekly transitions, too, as it goes around the SGG.
How messed up will these people's calendars be?

There are two other inhabited worlds. One is in a closer orbit to the main, so I assume that's a mining concern or research lab or some such. The other is on a smaller moon closer to the SGG (175,000km). It's not quite as nice as the atmosphere is thinner, but it has water [Y445465-5]. (It flies about the SGG every 31+ hours - I think that one could be tidally locked and still have a day/night cycle.)

Is there anywhere I could model this? Put in the parameters and then watch it play out? Or, that someone else could, and maybe record it for me?

Here's the entire system:
Code:
K0 V
Orbit 0 - Inner - Y200000-0
Orbit 1 - Inner - G130263-5
                  2 radii - ring
Orbit 2 - Inner - swept by companion
Orbit 3 - Habitable - M dwarf
                            Orbit 0 - SGG
                                      7 radii - Y445465-5
                                      20 radii - C660545-6
                                      30 radii - Y200000-0
                                      35 radii - YS00000-0
                                      40 radii - YS00000-0
                            Orbit 1 - LGG
                                      9 radii - Y210000-0
                                      11 radii - Y300000-0
                                      12 radii - Y300000-0
                                      275 radii - Y310000-0

(Note: I did fudge the mass numbers for the moons a little, and gave an arbitrary size to the SGG, based on Neptune. So, if you run the numbers and they're a little different, that may be why, besides rounding errors.)
 
I can't remember or find right now an article on binary star formations. There are basically 3 configurations:

  1. Close - stars are less than ~ 0.5 AU and closer; no planets will be formed until ~ 0.5 AU from the smaller star's orbit - the will be "swept" by the smaller star's gravitiy.
  2. Medium - stars from ~ 0.5 AU to ~ 6.0 AU; usually these are bigger stars and the gravitational tides might allow 1, rarely 2 planets inside the smaller star's orbit, then a gap until around double the smaller star's orbit.
  3. Distant - stars from ~ 6.0 AU and farther; planets can form around either star, out until the gravity from the other star starts interfering again.
It's been a couple of years since I read that and am not sure of the URL, or even whether that is a partially accepted theory anymore. Makes sense to me, though. :)
 
Right, Bill. I'm sticking with LBB6, though, and here's the quote:
If a companion is present, certain restrictions on available orbits exist. Orbits closer to the primary than the companion's orbit must be numbered no more than half of the companion's orbit number (round fractions down). Orbits farther away than the companion must be numbered at least two greater than the companion's orbit number.
For example, in a system with a companion in orbit 2, orbit 0 is available, and orbits 4 and higher are available. In a system with a companion at orbit 5, orbits 0, 1 and 2 are available, and orbits 7 and higher are available.
Companion stars have orbits as determined by the maximum orbits column, but may not exceed one-half their own orbit number (round fractions down).
(BTW, the LBB6 pdf is really bad in the OCR department. Yeesh.)
(PS, I didn't include the bit on close and far companions - which is akin to what you said.)
 
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That reminds me of something - according to the TravellerMap data, system 2508 in Massillia has eight stars - are there rules for systems like this? (The scenario is not impossible - the system of Castor has six stars IIRC)
 
I think LBB6 only has a very slim possibility for 4-5. I don't think 8 is doable under that generation system. The orbit rules in LBB6 would still apply, though, I would think.
 
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