Can you have habitable worlds with red dwarf?

this is a question for >>/sci/

>>51226260
>>>/sci/

>>51226255

I imagine so, although said habitable worlds will have to be closer in proximity to the red dwarf than Mercury is to our sun.

No, that thing was cringe-worthy. Especially the Cat.

>>51226255
Theoretically possible, but very difficult. If you mean "habitable by humans", then it becomes especially difficult.

Any planet close enough to a red dwarf to be habitable to humans (e.g. have liquid water on the surface) would be tidally locked, so one side of the planet is always facing the sun and the other is always facing away. That could potentially lead to massive massive MASSIVE storm systems covering the planet due to one side being super-heated and the other being frozen. And the planet would have to be almost completely covered in water, since if there are any continents or whatever to block the flow of water, the hot water would get stuck in one place and eventually boil off.

>>51226295
Listen here you little shit that show is amazing and the Cat one of the best things about it.

there's a few problems with red dwarf planets

a big one being planets in orbit around a red dwarf close enough to be in its habitable zone would be virtually guaranteed to be tidally locked, especially given a few billion years for evolution to put anything complex on its surface
in turn tidally locked planets have issues with water distribution, whereas on a non locked planet the rotation will cause a complex weather system distributing heat and water all over the planet, on a tidally locked one you'd get a gradual buildup on the shadow side, further helped by the constant gale winds created by the massive differences in temperature between dayside and nightside

then there's the issue that red dwarves have the tendency to vary significantly in energy output with cycles of up to 50% variance in luminosity having been observed. Our sun's variance is less than 0.1% for comparison.

Granted there are a lot of red dwarves around the the lower output of ionizing radiation is a benefit but I'd say you're better off with orange dwarves if you want a smaller star

>>51226463
>>51226423


New to the thread and not /sci/ educated, but why would theoretical planets close to a red dwarf be more likely to be tidally locked? Is that controlled by the distance to the star somehow?

>>51226463
>>51226423

I'm just passing through, but, why would a planet always be tidally locked with a red dwarf?

Is this one of those situations where a Red Dwarf is very LARGE, but very COOL and you have to huddle right up against it to get any heat -thus getting stuck- or... or what's the problem?

>>51226255

All stars have an habitable orbit where the temperature is good enough for Earth-like biospheres. But temperature is not the only problem here.

>>51226571
Yes.

Stars are so massive it's difficult to wrap your head around how massive they are. Even smaller ones. I don't know if you're familiar with the problem of Mercury's precession, but basically when you're as close to the sun as Mercury is, Newtonian gravity doesn't work right anymore.

Red dwarf stars are not very hot, by stellar standards, since they can only fuse hydrogen into helium and even that they do pretty slowly. So you have to get the planet very close to the star. And a planet that close would experience enormous tidal forces, since the difference in distance between its close side and its far side is so big relatively.

For context, a day on earth gets longer by roughly 2,000 seconds per hundred million years, mostly due to the gravitational effects of the moon. The moon is already tidally locked to the earth. And the ratio in mass of an earth-like planet to a red dwarf is much, much more than the ratio of the moon to the earth.

I'm not exactly the world's greatest expert myself, but I hope that helps.

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>>51226594
red dwarves are smaller but also vastly cooler than G and even K class stars

pic related is the habitable zone for proxima centauri

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>>51226594

http://terraforming.wikia.com/wiki/Habitable_Zone


http://terraforming.wikia.com/wiki/M_-_type_stars

>>51226571
the closer 2 objects are to eachother the stronger their tidal influence on eachother which will progress the planet towards tidal locking significantly faster
technically the earth is also progressing towards tidal locking with both the moon and the sun but neither events will be complete before the sun goes nova

also these stronger tidal forces have an additional issue in that they'll induce significant tidal heating in the planet resulting in a vastly more active geology to the point of actually inhibiting life on its surface.

>>51226295

Get the fuck out.

Right now.

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>>51226295
There needs to be some Final Solution camps for little shits like you.

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Permanent twilight. Very predictable weather patterns. No seasons. Trees grow tilted towards the star.

The universe is too young to have seen one die yet.

>>51226916
don't forget the perpetual hurricane covering almost 1/4th of the entire planet at the day side
and course while those weather patterns are predictable its along the lines of 24/7 100+mph single directional wind laced with sand particles.
If anything grows its either going to be in zones with relative calm wind generated by terrain or other conditions or else its going to have extremely though barks and heavily anchored root systems capable of enduring that sort of circumstances

Solar flares are going to be a bitch with any planet orbiting a red dwarf.

>>51227000

So you watched Alien Planet: Aurelia as well?

http://www.dailymotion.com/video/xkdb8x_extraterrestrial-aurelia_tech

What alternatives are there? Apart from red dwarfs.

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>>51227239

Every star has an habitable zone (orbit where there can be an Earth-like planet). However, different stars have different kinds of radiations and gravity that change things significantly. The smaller the star, the closer you have to get. The bigger the star, the farther you have to go.

>>51227180
nah, the hurricane and galeforce winds are fairly common knowledge about the conditions on tidally locked planets, I'll watch it later though

>>51227239
well you've got your regular ol' G class stars like our sun, then you've got the K class or orange dwarves which are smaller, but not to the point of racking up the red dwarf disadvantages while living significantly longer than G class stars and having less ionizing radiation.

At this point it seems like they are in fact the most likely candidates for alien life unless some unknown factors pop up.

On the other end of the spectrum you got the F class yellow-white stars which are just a step up from the G class. They're also not bad candidates for habitation sporting larger habitable zones. Though they do live shorter and are starting to output higher amounts of ionizing radiation.

Beyond that you've got the blue-white A class which is starting to approach the very limits of what could host life. They have immense habitable zones at vast distances but their increasingly shorter lives and higher intensity radiation as well as their increasing rarity make life difficult.
Example of this type of star is Sirius which you might know.

Then we have the B and the O class.
Life around a B would be a spectacular find to say the least and if there's anything living around an O class it was put there by an advanced civilization, they simply live to short a lives for anything to evolve (the largest O class we know of barely live 2-4 million years)

>>51227371

>Century/millenia-long seasons.

>>51227371
ah good ol R136a1
Folks who don't know about it, look that thing up, its insane in every possible way.
The current theory is that its simply to massive to have been formed the regular way and instead is most likely the result of 2 massive O class stars colliding

I guess people would be white as an albino on a planet orbiting a Red Dwarf (virtually no UV).

Meanwhile, a bigger star will have Carbon-black skin for too much UV.

>>51226916
>>51227000
Just make it a moon of a gas giant in the habitable zone.

>>51227446
Well, part of the reason Europeans have such light skin is because our ancestors had a diet very heavy in grain, which doesn't provide much vitamin D, so they needed to get more of it from the sun.

There's a reason Mongolians or the Inuit don't have pale skin.

>>51226255
No. Reasons for this are
>It's cold outside
>There's no kind of atmosphere
>You're all alone, more or less
>You must fly far away from here

>>51227728
that'd have less issues, you'd still have some funky weather systems with prolonged exposure and course quite a bit of darkness when it pops behind the giant and you even have some leeway for how long each rotation takes

that said it needs to be around a Saturn style planet, a moon orbiting a Jupiter or higher type monstrosity will be an irradiated volcanic hellhole

>>51227814
further explanation
>Let me fly, far away from here,
>Fun, fun, fun, In the sun, sun, sun.

>I want to lie, shipwrecked and comatose,
>Drinking fresh, mango juice,
>Goldfish shoals, nibbling at my toes,
>Fun, fun, fun, In the sun, sun, sun,
>Fun, fun, fun, In the sun, sun,

>>51226450
>>51226835
>>51226894
>lol smeg XD
>lol tryhard similes XD
>lol le curry monster XD
>lol teh computer is ment to be smart but it is dumb XD

It's cancerous dogshit. Compare it to something like Yes, Minister or Peep Show or Black Books and it's not even a contest.

KYS plz, cringelords.

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>>51226295
>>>/out/

>>51227961

Confirmed for only watching one episode.

>>51227961
Just because those are good doesn't mean other thing aren't.

>>51226255
Red Dwarf are long lived they are therefore the perfect stop for highly advanced civilization to put habitats in orbit.

>>51226255
https://en.wikipedia.org/wiki/Habitability_of_red_dwarf_systems