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Red dwarfs and Earth-like planets

Posted: Wed Feb 06, 2013 10:17 pm
by Cody
Interesting article - there are oodles of red dwarfs (shouldn't that be dwarves?).

Re: Red dwarfs and Earth-like planets

Posted: Wed Feb 06, 2013 10:58 pm
by Mad Dan Eccles
"Dwarfs" is the 'proper' plural (or dwerrow, even)... Tolkien popularized the word "Dwarves". http://grammarist.com/usage/dwarfs-dwarves/

Re: Red dwarfs and Earth-like planets

Posted: Wed Feb 06, 2013 11:20 pm
by Cody
Hmm... dwarfs does seem to be current for stellar objects. But I reckon it should be dwarves in normal usage.
Wasn't Tolkien a high-brow professor of English language, and something of an expert in the translation of Germanic words?

Re: Red dwarfs and Earth-like planets

Posted: Thu Feb 07, 2013 1:46 am
by CommRLock78
Perhaps Tolkien preferred dwarves since it follows the f => v pattern for plurals ending with f.

Re: Red dwarfs and Earth-like planets

Posted: Thu Feb 07, 2013 5:13 am
by Tricky
Arrrrgggggghhhhhhh!!!!!!!!!!

You just reminded me of a time when I lost many moons to the research of singular to plural and back again. I don't ever want to see this page on Wikipedia again: [Wikipedia] Plural form of words ending in -us

:evil:
The plural of Elvis is Elvii
:wink:

Re: Red dwarfs and Earth-like planets

Posted: Thu Feb 07, 2013 7:47 am
by PhantorGorth
Tricky wrote:
... I lost many moons to the research ...
From testing a Death Star OXP? :lol: :twisted:

Re: Red dwarfs and Earth-like planets

Posted: Fri Feb 08, 2013 12:27 am
by CommRLock78
Tricky wrote:
Arrrrgggggghhhhhhh!!!!!!!!!!

You just reminded me of a time when I lost many moons to the research of singular to plural and back again. I don't ever want to see this page on Wikipedia again: [Wikipedia] Plural form of words ending in -us

:evil:
The plural of Elvis is Elvii
:wink:
:lol: the old -us ending :D.

We don't have cactuses here in the S.W., but we do have cacti :).

Re: Red dwarfs and Earth-like planets

Posted: Fri Feb 08, 2013 9:14 am
by drew
Red Dwarfs are extremely common in the universe. Whether they have habitable planets remains quite the debate.

Personally I'm hoping they will have, I've got a couple of books that depend upon that possibility. :wink:

Cheers,

Drew.

Re: Red dwarfs and Earth-like planets

Posted: Fri Feb 08, 2013 10:01 am
by PhantorGorth
drew wrote:
Red Dwarfs are extremely common in the universe. Whether they have habitable planets remains quite the debate.
If they do exist they will have to be close to the star to be warm enough and therefore likely to be tidally locked with one face constantly facing the sun. (like the Moon is to the Earth.) This then means there would be a twilight strip around the planet that is habital between the extreme heat of the Sun facing side and the deep freeze of the far side.

Re: Red dwarfs and Earth-like planets

Posted: Fri Feb 08, 2013 12:47 pm
by drew
PhantorGorth wrote:
If they do exist they will have to be close to the star to be warm enough and therefore likely to be tidally locked with one face constantly facing the sun. (like the Moon is to the Earth.) This then means there would be a twilight strip around the planet that is habital between the extreme heat of the Sun facing side and the deep freeze of the far side.
You're absolutely correct, sir! :)

Cheers,

Drew.

Re: Red dwarfs and Earth-like planets

Posted: Sun Feb 10, 2013 2:25 am
by CommRLock78
PhantorGorth wrote:
drew wrote:
Red Dwarfs are extremely common in the universe. Whether they have habitable planets remains quite the debate.
If they do exist they will have to be close to the star to be warm enough and therefore likely to be tidally locked with one face constantly facing the sun. (like the Moon is to the Earth.) This then means there would be a twilight strip around the planet that is habital between the extreme heat of the Sun facing side and the deep freeze of the far side.
This is my understanding as well, but I think we shouldn't forget the possibility of companion moons, which could alleviate the tidal locking problem :). (i.e., if two bodies were tidally locked to each other there would be day and night).

Re: Red dwarfs and Earth-like planets

Posted: Sun Feb 10, 2013 2:44 am
by PhantorGorth
CommRLock78 wrote:
PhantorGorth wrote:
drew wrote:
Red Dwarfs are extremely common in the universe. Whether they have habitable planets remains quite the debate.
If they do exist they will have to be close to the star to be warm enough and therefore likely to be tidally locked with one face constantly facing the sun. (like the Moon is to the Earth.) This then means there would be a twilight strip around the planet that is habital between the extreme heat of the Sun facing side and the deep freeze of the far side.
This is my understanding as well, but I think we shouldn't forget the possibility of companion moons, which could alleviate the tidal locking problem :). (i.e., if two bodies were tidally locked to each other there would be day and night).
It all depends on what wins tidally. The moon would eventually move futher away and it's effect would reduce whereas the sun's effect would remain fairly constant so the sun would win in the long run.

Another point is you can have a system further out (even beyond the normally referred habital zone) and still be warm enough to support life by adding enough CO2 or other greenhouse gases to the atmosphere. Tidal locking would not be an issue for these types of planets.

Re: Red dwarfs and Earth-like planets

Posted: Sun Feb 10, 2013 5:06 am
by GGShinobi
PhantorGorth wrote:
Another point is you can have a system further out (even beyond the normally referred habital zone) and still be warm enough to support life by adding enough CO2 or other greenhouse gases to the atmosphere. Tidal locking would not be an issue for these types of planets.
You know what all this means, do you?? :shock: We are surrounded by hostile aliens who envy us for our powerful yellow sun!!! :? Most likely penguine-like beings capable of hacking computers with their bare feet!!! :shock: We need a Death Star to protect ourselves NOW!!! AAAAaaaaaaaaaaaaaaaaaahhhhhhhhhhhhh....
*runs of in panic*

Re: Red dwarfs and Earth-like planets

Posted: Sun Feb 10, 2013 5:21 am
by CommRLock78
PhantorGorth wrote:
It all depends on what wins tidally. The moon would eventually move futher away and it's effect would reduce whereas the sun's effect would remain fairly constant so the sun would win in the long run.

Another point is you can have a system further out (even beyond the normally referred habital zone) and still be warm enough to support life by adding enough CO2 or other greenhouse gases to the atmosphere. Tidal locking would not be an issue for these types of planets.
Interesting point. It would be great to find the simulator like this one that Pleb mentioned months back, which included moons as well (the one I know of that I linked to is great, but the simulated planet lacks a moon).
GGShinobi wrote:
You know what all this means, do you?? :shock: We are surrounded by hostile aliens who envy us for our powerful yellow sun!!! :? Most likely penguine-like beings capable of hacking computers with their bare feet!!! :shock: We need a Death Star to protect ourselves NOW!!! AAAAaaaaaaaaaaaaaaaaaahhhhhhhhhhhhh....
*runs of in panic*
:lol: :mrgreen: Penguins... :P

Edit: K-type stars have a lifetime over twice the lifetime of G-type star, and don't run the risk of having their Habitable Zone in range of the tidal locking zone.
Wikipedia: K-type main sequence star wrote:
Orange dwarfs are about three to four times as abundant as sun-like stars, making planet searches easier

Re: Red dwarfs and Earth-like planets

Posted: Sun Feb 10, 2013 9:34 pm
by CommRLock78
A slight digression - here's a little plot of Planck's Law using four different typical stellar type temperatures from F,G,K, and M.
Image
I have a hypothesis that plants on earth are green because that's where the peak intensity for the sun is, however, it will be a hard thing to prove or disprove until we have some other examples of plants from other sun types.