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Thread: Cataloging Exoplanets

  1. #1
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    Cataloging Exoplanets

    I'm thinking about adding a close binary companion to the parent star system of the planets I mentioned in my topic about orbital periods. If I do this, the planets will, obviously, be orbiting both stars. Noting the host galaxy's astronomers use ordinals to catalog start systems, do I have options other than cataloging the stars Ia Ib with the planets II and up and the stars being I and II with the planets as III and up?

  2. #2
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    Is this for a story?

    Quote Originally Posted by TurkeySloth View Post
    If I do this, the planets will, obviously, be orbiting both stars.
    This isn't a given. But I guess that depends on just how "close" the binaries are.


    Quote Originally Posted by TurkeySloth View Post
    ...do I have options
    If these are fictional astronomers - using their own cataloguing system - why are your options constrained? They don't have access to our nomenclature for naming solar system objects.

    What system would they logically create, given that the first star they observed - in their developing discipline of astronomy - was a binary?
    Last edited by DaveC426913; 2019-Jul-16 at 11:45 PM.

  3. #3
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    Quote Originally Posted by DaveC426913 View Post
    Is this for a story?


    This isn't a given. But I guess that depends on just how "close" the binaries are.




    If these are fictional astronomers - using their own cataloguing system - why are your options constrained? They don't have access to our nomenclature for naming solar system objects.

    What system would they logically create, given that the first star they observed - in their developing discipline of astronomy - was a binary?
    On your first point, I'm imagining the binary orbit close enough that planets can't exist between the stars, say 2.5-3.5 years.

    Secondly, they'd, very likely, combine the stellar names somehow. As to how and the resulting nomenclature, though, I don't know how they'd do so or think they'd be constrained. Thus, I defer to those of you more experienced than myself for other potential solutions. I based the current nomenclature on avoidance of clunky names, like theta Cassius Ab, for binaries with intrasystem planets, as opposed to those like my proposed system. Mind you, I picked the example designation out of thin air and have no clue is such a constellation/star exists.

  4. #4
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    Trying to read the minds of fictitious ETs is dicey.

  5. #5
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    Quote Originally Posted by Hornblower View Post
    Trying to read the minds of fictitious ETs is dicey.
    Indeed.

    In fact, TurkeySloth - this is an opportunity.

    As a rule of thumb, events in a story should wear multiple hats, so you have a story with all the detail and pacing without being overly-burdened with expositional facts. If you are going to go into detail about their nomenclature, that's actually not very interesting in-and-of-itself. The real purpose of any such world-building element is to tell us something more about the them.


    In fact, look at this challenge the other way around. Figure out what you want us to learn about how your aliens live and think - and then figure out how their peculiar nomenclature demonstrates it. Make the nomenclature do work for you.

    Do they have a different counting base? 8? or 12? Do they have a preoccupation with colour? With animals? With historical gods?

    That's the story. The nomenclature is simply a vehicle for teaching us about who they are.

  6. #6
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    Here's a spurious example:

    Your characters' society happens to involve a strong family component. When the ancients look up at the sky, they see two life-giving bodies, and a bunch of smaller dependent bodies. Naturally, the stars were first named Mother and Father, all the planets are daughters (gas giants) and sons (rocky bodies). (It never occurs to them to have a unified naming system for different types of sibling planets.)

    When they start looking out to other systems, they realize for the first time that "star families" don't always have two "parents" - in fact - the majority of them happen to have only one parent. By that time, their nomenclature is fixed. A primary star is designated M### (for Mother) and a secondary star is F### (Father). Planets are M###m# or M###f#.


    You don't have to mention any of this explicitly in exposition; it will come up in normal story interaction. And the beauty of that is, whenever you might have to talk about dry planetary science, you also have an excuse to talk about the subtleties of their society. How funny it is to think of a family as only having one parent. It must be cold and dark there.

    Now, your sciencey exposition is actually telling us about your characters. And that is your primary job as an author.

    This was just a random pick. Your characters surely have their peculiarities your can leverage. Season to-taste.

  7. #7
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    Geez! I really need to pay more attention to this place because you guys are providing extremely useful information.

    I love that example, DaveC.

  8. #8
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    But back in the non-fictional world, circumbinary nomenclature is a mess. The stars of your binary would be designated SomeStar A and SomeStar B. The first discovered planet around SomeStar A would be SomeStar Ab, and similarly SomeStar Bb. But if the planet orbits both stars, people have got up to all sorts of strange things - numbering the planets from 3, or lettering them from c.

    Hessman et al. (2010) proposed a (to me) more sensible approach, going for SomeStar (AB)b for the first discovered. The paper is maybe worth reading just to get a feel for the possibilities.

    Grant Hutchison

  9. #9
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    That paper was a great read, Grant.

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