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Thread: Human life under a Blue Dwarf Sun?

  1. #1 Human life under a Blue Dwarf Sun? 
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    I'm working on creating a planet based off of viable scientific theory for a science fantasy novel I'm writing...

    In all of my research, I do find that human life on such a planet isn't too likely or at least isn't really speculated on. This part of the story background is deliberate manipulation by a cosmic deity. So far, the planet looks like a super-earth orbiting a K-type star. The sky is bright blue, the "greenery" is red/orange.

    Where I'm stuck is at whether the melanin in human skin would still be the same colors that that it is on earth. If I've got my facts straight, a K type star probably won't give off too much radiation. So, is there even much of a need for melanin? If not, would humans in cloudy weather areas of the planet possibly have translucent or just unpigmented skin? (And what would that look like? Would it appear the greenish color that our veins do in places we can see them beneath the skin?)

    If anyone could offer me any advice or point me in the right direction for further research I'd be eternally grateful. I hope that so far I've been able to make sense.


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  3. #2  
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    Is your novel to explore some scientific concept (theory) or is the science just background for a type of romance story.

    If the science part is just about background then all you need is Phlebotinum.

    From Wise Geek:
    "Phlebotinum is a device that is used to advance a plot, classically in the television industry, although it can also appear in books and films. By its nature, it is usually inexplicable and often magical, with no basis in reality. It exists solely to propel the plot forward without unnecessary fuss, ideally with a minimum of suspension of disbelief. As one might imagine, phlebotinum is especially common in science fiction and fantasy, where unusual plot devices can be more believable.

    The term was coined by the Buffy the Vampire Slayer writing team, when the writers were working on an episode and having trouble getting it to advance. As they struggled, one of the writers shouted “don't touch the phlebotinum in the corner,” and the term was born. The Buffyseries is somewhat famous for such devices, with a variety of mystical objects and events being used to propel the arc of the story.

    One of the most famous examples is probably kryptonite, the mysterious substance which is harmful to Superman. Phlebotinum often pops up when writers need a way to push a story, and they want to avoid a complex circumlocution that may require several episodes to unfold. By throwing phlebotinum into the mix, they can advance the story rather than focusing on the details, keeping readers interested and giving their characters something new to work with and play against."

    However be careful of Misapplied Phlebotinum
    http://tvtropes.org/pmwiki/pmwiki.php/Main/MisappliedPhlebotinum


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  4. #3  
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    I want to avoid phlebotinum every chance I can get. I suppose my cosmic god thing whose planting human life on planets all over the universe is that exactly, but I don't want the story to be saturated with it.

    I may just have to make the decision of what their skin is like without any research or theory to back it up... and I will if I have to, but I thought I would do my best to be somewhat realistic when I can.

    It's not a romance story. It's about human nature and whether or not humans can really be "good", which is what the "god" is trying to discover by experimenting with different planets. I just want to avoid the whole green/blue skinned alien thing. Unless that's what might actually be possible.

    It just seems to me that if plants would be orange because the rest of the spectrum is more efficient for them to use under a blue sun, then wouldn't melanin also choose a different color?

    Here's my sources for my info so far if it helps anything:

    Orion's Arm - The Sky on Alien Worlds

    Color of Life | Alien Realities
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  5. #4  
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    I can't really help more than I just did.
    You are at least clear about what the book is about, and it is about the problem of good and evil instead of science.

    My only other advice is to edit, edit, edit.
    You will find yourself throwing away a lot of words but it is better than being excessively wordy and boring.

    PS: Don't be too afraid of phlebotinum. it is fine if properly used.
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    Okay, well thank you very much for your time.

    You're probably right about the phlebotinum. I'm leaning towards translucent/ opaque white / violet shades of skin if I can't find any good theory to go by. There's plenty of room in the plot to get into the scientific theory of why certain things are the way they are but I doubt any of the characters will be examining why their skin is the color that it is anyways. :P
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  7. #6  
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    Quote Originally Posted by Aello View Post
    Okay, well thank you very much for your time.

    You're probably right about the phlebotinum. I'm leaning towards translucent/ opaque white / violet shades of skin if I can't find any good theory to go by. There's plenty of room in the plot to get into the scientific theory of why certain things are the way they are but I doubt any of the characters will be examining why their skin is the color that it is anyways. :P
    I'd have thought that, if your sun is blue, the UV emissions will be a bigger proportion of the solar output than here on Earth. Since UV photons are more energetic than visible and IR ones, they will tend to promote photolysis reactions in the complex molecules that I assume you require for life on your planet. So I think you might find your creatures need better shielding from UV than we typically find here on Earth. Melanin does a good job of this (and is also a good radical scavenger, so limits the damage caused by any reactions that do take place) , though other compounds that are not black, e.g those used in sun block creams, would also do so.

    Of course you could go the other way and assume a wider variety of creatures photosynthesise on your world, exploiting the energy of blue/UV, in which case you'd be looking for a pigment that captures and harnesses the energy, rather than just dissipating it as heat, as melanin does.
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  8. #7  
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    Quote Originally Posted by Aello View Post
    I'm working on creating a planet based off of viable scientific theory for a science fantasy novel I'm writing...

    In all of my research, I do find that human life on such a planet isn't too likely or at least isn't really speculated on. This part of the story background is deliberate manipulation by a cosmic deity. So far, the planet looks like a super-earth orbiting a K-type star. The sky is bright blue, the "greenery" is red/orange.

    Where I'm stuck is at whether the melanin in human skin would still be the same colors that that it is on earth. If I've got my facts straight, a K type star probably won't give off too much radiation. So, is there even much of a need for melanin? If not, would humans in cloudy weather areas of the planet possibly have translucent or just unpigmented skin? (And what would that look like? Would it appear the greenish color that our veins do in places we can see them beneath the skin?)

    If anyone could offer me any advice or point me in the right direction for further research I'd be eternally grateful. I hope that so far I've been able to make sense.

    A K class star will emit UV at between 1/12 to 1/3 the intensity that Sol does depending on where in the K range it falls.

    A K class star will also mass between 0.6 and 0.9 solar masses and have a luminosity of 0.11 to 0.38 that of Sol's.

    To be in the habitable zone, a planet would have to orbit between 0.33 and 0.62 AU from the star.

    When you move in closer to keep the planet warm, you also increase the UV exposure. Thus, at Earth light levels, the effective UV levels would be from 0.76-0.88 that of Earth levels.

    The year for such a planet would run from 89-187 days.

    Now these are base values, and you could move your planet out further if you could increase the greenhouse effect of the atmosphere.

    I'm not sure what atmospheric pressure you are planning for your Super-Earth planet (or what size the planet is), But at Earth normal pressures, one could increase the CO2 percentage by some 30 times before it becomes dangerous over a lifetime. So you could move your planet out and increase the CO2 in the atmosphere to compensate.

    If you are considering this as a terraformed world, this shouldn't cause a problem.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  9. #8  
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    Exchemist-- So my people will mostly all be dark skinned? That's the opposite of what I had assumed. Thanks for the insight, it really helps!

    Janus-- Thank you, that's really helpful. I hadn't really thought much about the atmosphere yet... I'll need to learn a bit more before I make the decision. But you've given me a great starting point!

    Turns out some of my ideas were completely wrong! Thanks for setting me straight, guys.
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  10. #9  
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    Quote Originally Posted by Janus View Post
    Quote Originally Posted by Aello View Post
    I'm working on creating a planet based off of viable scientific theory for a science fantasy novel I'm writing...

    In all of my research, I do find that human life on such a planet isn't too likely or at least isn't really speculated on. This part of the story background is deliberate manipulation by a cosmic deity. So far, the planet looks like a super-earth orbiting a K-type star. The sky is bright blue, the "greenery" is red/orange.

    Where I'm stuck is at whether the melanin in human skin would still be the same colors that that it is on earth. If I've got my facts straight, a K type star probably won't give off too much radiation. So, is there even much of a need for melanin? If not, would humans in cloudy weather areas of the planet possibly have translucent or just unpigmented skin? (And what would that look like? Would it appear the greenish color that our veins do in places we can see them beneath the skin?)

    If anyone could offer me any advice or point me in the right direction for further research I'd be eternally grateful. I hope that so far I've been able to make sense.

    A K class star will emit UV at between 1/12 to 1/3 the intensity that Sol does depending on where in the K range it falls.

    A K class star will also mass between 0.6 and 0.9 solar masses and have a luminosity of 0.11 to 0.38 that of Sol's.

    To be in the habitable zone, a planet would have to orbit between 0.33 and 0.62 AU from the star.

    When you move in closer to keep the planet warm, you also increase the UV exposure. Thus, at Earth light levels, the effective UV levels would be from 0.76-0.88 that of Earth levels.

    The year for such a planet would run from 89-187 days.

    Now these are base values, and you could move your planet out further if you could increase the greenhouse effect of the atmosphere.

    I'm not sure what atmospheric pressure you are planning for your Super-Earth planet (or what size the planet is), But at Earth normal pressures, one could increase the CO2 percentage by some 30 times before it becomes dangerous over a lifetime. So you could move your planet out and increase the CO2 in the atmosphere to compensate.

    If you are considering this as a terraformed world, this shouldn't cause a problem.
    Janus that's interesting because it means I was talking rubbish.

    But tell me how this works, with a K class star. I would have thought if it looks blue it must have a higher surface temperature than our sun and consequently its black body output would be shifted to the blue, relative to our sun, and thus for a given level of light intensity in the visible range, the UV output would be higher. But you are saying that for equal light intensity the UV intensity would be only around 3/4 that of our sun. How does this arise? Or rather, where is my error in reasoning?
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  11. #10  
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by Janus View Post
    Quote Originally Posted by Aello View Post
    I'm working on creating a planet based off of viable scientific theory for a science fantasy novel I'm writing...

    In all of my research, I do find that human life on such a planet isn't too likely or at least isn't really speculated on. This part of the story background is deliberate manipulation by a cosmic deity. So far, the planet looks like a super-earth orbiting a K-type star. The sky is bright blue, the "greenery" is red/orange.

    Where I'm stuck is at whether the melanin in human skin would still be the same colors that that it is on earth. If I've got my facts straight, a K type star probably won't give off too much radiation. So, is there even much of a need for melanin? If not, would humans in cloudy weather areas of the planet possibly have translucent or just unpigmented skin? (And what would that look like? Would it appear the greenish color that our veins do in places we can see them beneath the skin?)

    If anyone could offer me any advice or point me in the right direction for further research I'd be eternally grateful. I hope that so far I've been able to make sense.

    A K class star will emit UV at between 1/12 to 1/3 the intensity that Sol does depending on where in the K range it falls.

    A K class star will also mass between 0.6 and 0.9 solar masses and have a luminosity of 0.11 to 0.38 that of Sol's.

    To be in the habitable zone, a planet would have to orbit between 0.33 and 0.62 AU from the star.

    When you move in closer to keep the planet warm, you also increase the UV exposure. Thus, at Earth light levels, the effective UV levels would be from 0.76-0.88 that of Earth levels.

    The year for such a planet would run from 89-187 days.

    Now these are base values, and you could move your planet out further if you could increase the greenhouse effect of the atmosphere.

    I'm not sure what atmospheric pressure you are planning for your Super-Earth planet (or what size the planet is), But at Earth normal pressures, one could increase the CO2 percentage by some 30 times before it becomes dangerous over a lifetime. So you could move your planet out and increase the CO2 in the atmosphere to compensate.

    If you are considering this as a terraformed world, this shouldn't cause a problem.
    Janus that's interesting because it means I was talking rubbish.

    But tell me how this works, with a K class star. I would have thought if it looks blue it must have a higher surface temperature than our sun and consequently its black body output would be shifted to the blue, relative to our sun, and thus for a given level of light intensity in the visible range, the UV output would be higher. But you are saying that for equal light intensity the UV intensity would be only around 3/4 that of our sun. How does this arise? Or rather, where is my error in reasoning?

    A K class would be orange not blue. So the confusion was in the OP's title.

    Since he mentioned a K class star and low UV, I assumed he the title was a mistake.

    A Blue Dwarf is a hypothetical type of star that would form after a M class star with less than 0.25 solar masses burns up most of it hydrogen supply. They are hypothetical due to the fact that M class stars remain in the main sequence for so long that there has not been enough time for any Blue dwarfs to form yet.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  12. #11  
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    Quote Originally Posted by Janus View Post

    A K class would be orange not blue. So the confusion was in the OP's title.

    Since he mentioned a K class star and low UV, I assumed he the title was a mistake.

    A Blue Dwarf is a hypothetical type of star that would form after a M class star with less than 0.25 solar masses burns up most of it hydrogen supply. They are hypothetical due to the fact that M class stars remain in the main sequence for so long that there has not been enough time for any Blue dwarfs to form yet.
    Oh, crap, you're right. I had everything mixed up. It turns out that one of my sources above listed K type stars as being hot and blue when they're not.

    Ok, I was partial to blue light, but an actual K class is still looking pretty good. It may actually make things easier for me in the long run.

    Thanks for clearing that up. No wonder you guys were talking about the opposite of what I thought I'd learned! :P

    One more question if you don't mind: Am I tidally locked on my planet?
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  13. #12  
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    Quote Originally Posted by Aello View Post
    Quote Originally Posted by Janus View Post

    A K class would be orange not blue. So the confusion was in the OP's title.

    Since he mentioned a K class star and low UV, I assumed he the title was a mistake.

    A Blue Dwarf is a hypothetical type of star that would form after a M class star with less than 0.25 solar masses burns up most of it hydrogen supply. They are hypothetical due to the fact that M class stars remain in the main sequence for so long that there has not been enough time for any Blue dwarfs to form yet.
    Oh, crap, you're right. I had everything mixed up. It turns out that one of my sources above listed K type stars as being hot and blue when they're not.

    Ok, I was partial to blue light, but an actual K class is still looking pretty good. It may actually make things easier for me in the long run.

    Thanks for clearing that up. No wonder you guys were talking about the opposite of what I thought I'd learned! :P

    One more question if you don't mind: Am I tidally locked on my planet?
    I'd still go for blue if I were you - far more exotic for readers to imagine. Janus isn't saying they can't exist, after all.
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    i don't know if you saw the movie pitch black and the chronicles of riddick, with the great intellectual vin diesel.
    They use a simple special effect there. If they are on a planet with a sun/suns with some dominant color, all the colors get filtered in the appropriate way.


    For example if the sun is blue, everything looks blue with less other colors. So you get a very extraterrestrial look of the planet's surface. I find this very interesting, because its a very simple special effect to make, yet its the only example i'm aware of, that actually do that. I'm saying this, because probably you didn't thought of that detail, that the colors will look distorted with an other sun.
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  15. #14  
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by Aello View Post
    Quote Originally Posted by Janus View Post

    A K class would be orange not blue. So the confusion was in the OP's title.

    Since he mentioned a K class star and low UV, I assumed he the title was a mistake.

    A Blue Dwarf is a hypothetical type of star that would form after a M class star with less than 0.25 solar masses burns up most of it hydrogen supply. They are hypothetical due to the fact that M class stars remain in the main sequence for so long that there has not been enough time for any Blue dwarfs to form yet.
    Oh, crap, you're right. I had everything mixed up. It turns out that one of my sources above listed K type stars as being hot and blue when they're not.

    Ok, I was partial to blue light, but an actual K class is still looking pretty good. It may actually make things easier for me in the long run.

    Thanks for clearing that up. No wonder you guys were talking about the opposite of what I thought I'd learned! :P

    One more question if you don't mind: Am I tidally locked on my planet?
    I'd still go for blue if I were you - far more exotic for readers to imagine. Janus isn't saying they can't exist, after all.
    Unless you place the story some trillions of years in the future, then yeah, they can't exist. That's how long it would take for a red dwarf to become a blue dwarf.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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    Quote Originally Posted by Quantum immortal View Post
    i don't know if you saw the movie pitch black and the chronicles of riddick, with the great intellectual vin diesel.
    They use a simple special effect there. If they are on a planet with a sun/suns with some dominant color, all the colors get filtered in the appropriate way.


    For example if the sun is blue, everything looks blue with less other colors. So you get a very extraterrestrial look of the planet's surface. I find this very interesting, because its a very simple special effect to make, yet its the only example i'm aware of, that actually do that. I'm saying this, because probably you didn't thought of that detail, that the colors will look distorted with an other sun.
    Oh thank you, that's very helpful. I'll check those out.
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    Quote Originally Posted by Janus View Post

    Unless you place the story some trillions of years in the future, then yeah, they can't exist. That's how long it would take for a red dwarf to become a blue dwarf.
    The time frame doesn't really matter, so that's not actually a problem for my world. Thanks.
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  18. #17  
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    Quote Originally Posted by Aello View Post
    Quote Originally Posted by Janus View Post

    Unless you place the story some trillions of years in the future, then yeah, they can't exist. That's how long it would take for a red dwarf to become a blue dwarf.
    The time frame doesn't really matter, so that's not actually a problem for my world. Thanks.
    Okay, just remember that the universe is going to being a lot different place in that long of a time from now. The larger, hotter suns will have all burned out and new star formation will have ceased. There will only be the corpses of stars, some blue dwarfs and whatever red dwarfs that haven't yet reached the end of the main sequence left. Since these are all very dim, the night sky is going to be very empty. (to give you an idea, most of the stars within 20 light years of Earth are M class red dwarfs and none of them are visible by the unaided eye.)
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  19. #18  
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    Quote Originally Posted by Janus View Post
    Quote Originally Posted by Aello View Post
    Quote Originally Posted by Janus View Post

    Unless you place the story some trillions of years in the future, then yeah, they can't exist. That's how long it would take for a red dwarf to become a blue dwarf.
    The time frame doesn't really matter, so that's not actually a problem for my world. Thanks.
    Okay, just remember that the universe is going to being a lot different place in that long of a time from now. The larger, hotter suns will have all burned out and new star formation will have ceased. There will only be the corpses of stars, some blue dwarfs and whatever red dwarfs that haven't yet reached the end of the main sequence left. Since these are all very dim, the night sky is going to be very empty. (to give you an idea, most of the stars within 20 light years of Earth are M class red dwarfs and none of them are visible by the unaided eye.)
    That could actually work really well. I kinda like the idea of a bleak night sky in a dying part of the universe as the backdrop for my planet. Thanks again for your help.
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