The Taldain Solar System

[Stormgate]

So, it's no secret that Taldain is locked in an orbit that makes one side perpetually daytime, and the other always night. However, I have heard that when Sanderson was coming up with the world, he had one side lit by a strange, weak star. I was wondering how this would work, when I came upon an article from XKCD about what the rainbows on Tattooine would look like. In it, there are two different types of solar systems with two stars:

Taldain is the "other kind," and, as is stated in the article, the outer star can easily be darker.

 

What I'm saying is that Taldain is possible. Survival on Taldain would arguably be harder than on Roshar, but it's possible.

[Yata]

To survive on Taldain you have just to have an high UV resistence (or use the rightful protection) and of course know a bit its ecology.

[teknopathetic]

The planet seems to soak up the UV somehow. The Daysiders have pale skin and no visible signs of sunburns. Heck, they even don't wear sunglasses or hats most of the time.

 

I have two guesses:

1. The planet is redirecting the UV to Darkside somehow.

2. The omnipresent clouds (as seen in the Graphic Novel) are somehow absorbing most of the UV radiation. My gut tells me that water is invested in this planet, and the clouds are much more important than we think. If you've seen the Cloud Faces post then you've seen more evidence of water magic there too. 

[Yata]

5 hours ago, teknopathetic said:

The planet seems to soak up the UV somehow. The Daysiders have pale skin and no visible signs of sunburns. Heck, they even don't wear sunglasses or hats most of the time.

Well they may have a Star who emits little UV...Or like you said an atmosphere who filtres them very well (but it would be in common with Darkside).

But I am a little doubtful about the "little UV" on Dayside. Eric after all spent some year on Darkside and he wasn't burned or something like that... This mean that a Dayside's Human have still an high UV resistence.

[Pathfinder]

I know very little of astronomy, but would the fact that there is a moon circling Taldain affect this model at all?

[Yata]

5 hours ago, Pathfinder said:

I know very little of astronomy, but would the fact that there is a moon circling Taldain affect this model at all?

Mmm If I don't remember wrong the moon is always visible on dayside and work like a "meridian" to dayside's people... Therefore "the other kind" model have to be little different... The moon have to travel in a plane orthogonal to the one where Taldain and the Sun move.

[Pathfinder]

5 minutes ago, Yata said:

Mmm If I don't remember wrong the moon is always visible on dayside and work like a "meridian" to dayside's people... Therefore "the other kind" model have to be little different... The moon have to travel in a plane orthogonal to the one where Taldain and the Sun move.

From what I recalled, the moon did move and they used it to tell time by (when the moon passes the mountain for instance). I also feel like I remember seeing somewhere it being stated the moon set, but that part at least I could be remembering incorrectly. 

[teknopathetic]

16 hours ago, Yata said:

 

But I am a little doubtful about the "little UV" on Dayside. Eric after all spent some year on Darkside and he wasn't burned or something like that... This mean that a Dayside's Human have still an high UV resistence.

Well everyone on Darkside glows in the dark: teeth, nails, etc. There is a lot of strange light bombarding Nightside. The 2nd sun must be very far away, and I doubt all that energy could be (naturally) coming from the 2nd sun. 

[Kingsdaughter613]

I keep thinking the second 'sun' is actually a neutron star. They emit little light but a lot of radiation; the light they emit is unusual and could be described as 'dark light'; and they do occasionally appear in Binary systems. Thing is, the inner star would then be Dark Side's as neutron stars have more mass but less area than regular stars. (They are basically black hole failures.)

[Stark]

What I find fascinating is that the skin tones of the people there are opposite of what we see on Earth.  The Daysiders who live in the desert are all pale skinned, where as the Darksiders all have darker skin tones.  It brings all kinds of interesting questions about the science of the planet.  

-What kind of Star do they orbit that emits little to know UV radiation, leaving the Daysiders with low Melanin counts?  What faces the Darkside that causes such a high Melanin count in the absence of light?

[Pattern]

The inner sun is a blue-white super-giant star (lifetime only some 10 million years), so there is a lot of UV on dayside, too. The planet would be gravitationally locked to the inner star with the dominating mass, synchronizing eigenrotation with the orbit around the star. The problem with this model: the smaller outer star - a white dwarf (some billion years old) - would not always be visible from Darkside, because it has a much larger orbital period than the planet. So with the planet locked to the inner star, Dayside would sometimes get radiation from both stars while Darkside would be, well, dark. Gravitationally the white dwarf would have only little influence on Taldain since the mass of a super-giant is multiple times (10-50x) the solar mass while a white dwarf has a maximum of 1.44 solar masses. However, that is not how the system is described in AU.

So much to physics. Now we have a shard in that system, that acts somewhat strangely compared to its intent, as discussed in another thread. Here my - a little bit silly - proposition:

Autonomy/Bavadin is permanently pushing the outer star, so it keeps up with the planet's orbit time and is visible from darkside all the time. That keeps her quite occupied since it costs LOTS of energy.

Of course, Taldain could also sit exactly at the center of mass of the binary system, a point of unstable equilibrium. Stabilization via Shard would be "easier" than pushing the white dwarf on its orbit.

Another question is: How could a supermassive star form near an old white dwarf - or more likely near a red giant which became a white dwarf not so long ago? Usual star formation happens in cold, dark regions with accumulated matter. - The particulate ring is probably the outer hull of the star which ultimately became the white dwarf, an event that can not be too far in the past, since the ring is still small (smaller than the Taldain system).

Edited January 10, 2017 by Pattern
Correcting terms

[Jofwu]

On 1/10/2017 at 4:01 AM, Pattern said:

Of course, Taldain could also sit exactly at the center of mass of the binary system, a point of unstable equilibrium. Stabilization via Shard would be "easier" than pushing the white dwarf on its orbit.

This seems most likely to me.

Don't know enough about astrophysics to address your question.

[BobyVass]

On 1/10/2017 at 11:01 AM, Pattern said:

Another question is: How could a supermassive star form near an old white dwarf - or more likely near a red giant which became a white dwarf not so long ago? Usual star formation happens in cold, dark regions with accumulated matter. - The particulate ring is probably the outer hull of the star which ultimately became the white dwarf, an event that can not be too far in the past, since the ring is still small (smaller than the Taldain system).

What happened there is maybe similar to what happened to the Eta Carinae system: this

As the second star (which is now a white dwarf) became a red or a blue giant (it may have easily been a star with 10-20 Solar masses), the first star (that is now a white-blue supergiant) accreted material from the second one. What is left from the second star is its core- a white dwarf and a hypergiant star as the first one.

The only way this system is possible is to have the planet in the exact center of mass of the system.

On 1/10/2017 at 11:01 AM, Pattern said:

Of course, Taldain could also sit exactly at the center of mass of the binary system, a point of unstable equilibrium. Stabilization via Shard would be "easier" than pushing the white dwarf on its orbit.

Then, assuming the supergiant must have 40-50 solar masses and the white dwarf is 1.4 max, then the planet should be approximately 40 times closer to the big star then to the dwarf. Knowing the surface temperatures on the dayside are not like 1000K or more, the distances should be BIG. So the orbital periods should go to hundreds of years. 

Maybe the planet's atmosphere is very reflective or absorbing in the UV spectrum, otherwise people on the bright side would be black. People on the dark side have darker skin because the white dwarf usually has a surface temperatures as high as 100000K, which makes it glow almost entirely in UV. Then, the most of the UV light from the bigger star will be absorbed / reflected, which also applies for the dwarf, but it produces hundreds times more UV than a regular star, so it becomes noticeable on the surface, resulting in darker skin and fluorescent glow.

But, there is a problem, the dark side would be REALLY cold if the temperatures on the bright side are not extreme. So there must be some really big air mass movements to distribute heat more evenly across the planet, which may be the Shard's work to make the planet more inhabitable.

Even if this exists, everyone on the bright side will be instantly pierced with Industrial quantities of high-energetic particles, resulting in almost instant death or radioactive poisoning in the matter of seconds. The only solution to this problem is a VERY STRONG magnetic field, wrapping the planet, which can be created in two ways
1. Fast spinning molten metal core of the planet (like on Earth, but bigger and faster spinning), which is not possible, because Taldain is practically not spinning.
2. Magic

Well, thats all from me. Have a great day!