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Tassie Devil
2009-May-04, 11:54 AM
Hello everyone. A newbie to this forum, but a question thats been bugging me.

Given that we know that life exists at a certain distance from a certain size star (in our solar system), do planet hunters, use a smilar formula when looking for planets orbitting other stars?
Thanks.

PraedSt
2009-May-04, 12:36 PM
Hi Tassie Devil. Welcome to BAUT. :)

Amateur answer:

Yes and no. We've only just begun finding extrasolar planets, so at this stage astronomers are trying to find as many planets as they can. Of course, they're very happy if they do find a planet within the habitable zone, but as far as I'm aware, no special effort is (as yet) directed towards finding these. Rather, right now I think that they're more focused on finding Earth-size planets- which is quite hard to do as these relatively small in the big scheme of things.

EDIT: Ha! My answer is sort-of wrong. The Kepler Mission (http://en.wikipedia.org/wiki/Kepler_Mission) will try to find Earth-sized planets- hopefully within the habitable zone. We have a running thread on the mission here (http://www.bautforum.com/space-exploration/24311-kepler-mission-5.html).

Wizard From Oz
2009-May-04, 02:14 PM
Tassie, as PraedSt pointed out we are only just getting started on the whole process. For now, the definition of the inhabitable zone is anywhere liquid water can exist. This is fairly arbitary because all our biological science is based on conditions we find on Earth.

On the other hand we can fairly well predict how far from a specific star this zone should be found. Some stars have no such zone because they are too bright or dim etc etc

Tassie Devil
2009-May-05, 12:31 AM
Thanks guys. So we understand a "habitable zone", from what we know about our own solar system (Mass of sun, distance etc), and we apply that basic template to planet hunting.... although we are looking at anything that shows a sign of something orbitting another star, at this early stage?
Makes sense. Although listening to Astronomycast, the new telescopes being manufactured / launched should really let us get better images etc?

galacsi
2009-May-05, 09:47 AM
Tassie, as PraedSt pointed out we are only just getting started on the whole process. For now, the definition of the inhabitable zone is anywhere liquid water can exist. This is fairly arbitary because all our biological science is based on conditions we find on Earth.

On the other hand we can fairly well predict how far from a specific star this zone should be found. Some stars have no such zone because they are too bright or dim etc etc

Hello Wizard :

I think all stars have an habitable zone. for a brighter star than Earth it will be farther away and for a dimmer , by example a red dwarf , it will be nearer . But of course there are other parameters , a very bright star is very short lived (If Mainstream is correct) and a very dim star has its own problems ; frequent flares and tidal locking. But ,in both cases , it does not prevent planets existing inside this habitable zone.

astromark
2009-May-05, 10:00 AM
Do not expect to see images of exo-solar planets becoming common. It has been done but, the distances are prohibitive. So other methods are used to detect the planets of other stars.
The real work is finding them. Many hundreds of ccd images of distant stars taken weeks and months apart. Looking for two sign's that give indercation of planetary mass. A sudden dimming indercating a planetary acultation., or a small regular wobble giving a clue to some orbital mass. hours of observatory work and also hours at the computer. Looking for those small irregular clues to the presence of planets. Looking for planets that are small and in the sweat zone will come as the methods improve

Tassie Devil
2009-May-05, 11:42 AM
Thanks everyone...

I am assuming that the last comment was meant to be "sweet zone", or is "sweat zone" in reference to the amount of work required to find them?

PraedSt
2009-May-05, 11:56 AM
we are looking at anything that shows a sign of something orbitting another star, at this early stage?
Makes sense. Although listening to Astronomycast, the new telescopes being manufactured / launched should really let us get better images etc?
That's about right, yes.
More on finding planets : Methods of detecting extrasolar plants (http://en.wikipedia.org/wiki/Methods_of_detecting_extrasolar_planets)
There are numerous ground based observatories and projects trying to find planets- too numerous for me to mention.
But some space missions and observatories: COROT (http://en.wikipedia.org/wiki/COROT) (current), Kepler (http://en.wikipedia.org/wiki/Kepler_Mission) (current), Darwin (http://en.wikipedia.org/wiki/Darwin_%28ESA%29) (>2015)
And our very own ongoing thread: Interesting extrasolar planet discoveries (http://www.bautforum.com/astronomy/58157-interesting-extrasolar-planet-discoveries.html)

Tassie Devil
2009-May-05, 12:14 PM
Thanks PraedSt. Exactly why I joined this forum.

astromark
2009-May-05, 07:22 PM
Thanks everyone...

I am assuming that the last comment was meant to be "sweet zone", or is "sweat zone" in reference to the amount of work required to find them?

Please tell me you are joking...

Tassie Devil
2009-May-05, 10:29 PM
Yes, just joking.

Wizard From Oz
2009-May-06, 12:46 AM
Hello Wizard :

I think all stars have an habitable zone. for a brighter star than Earth it will be farther away and for a dimmer , by example a red dwarf , it will be nearer . But of course there are other parameters , a very bright star is very short lived (If Mainstream is correct) and a very dim star has its own problems ; frequent flares and tidal locking. But ,in both cases , it does not prevent planets existing inside this habitable zone.

Well I was looking at it from the energy side. A star could be close enough to Rigel to have liquid water, but the dosing of other radiation hitting the planet would be bistering. Moving the planet far enough away to survive this element puts it too far out to recieve enough heat for water.

But your point about short lived energetic stars is valid.

galacsi
2009-May-06, 09:41 AM
Well I was looking at it from the energy side. A star could be close enough to Rigel to have liquid water, but the dosing of other radiation hitting the planet would be bistering. Moving the planet far enough away to survive this element puts it too far out to recieve enough heat for water.

But your point about short lived energetic stars is valid.


Rigel star is an extreme example ! Only 0.13% of stars belong to this type. It is 40,000 times brighter than the sun , or 66,000 if you count UV. Yes there is more UV in its spectrum than in our own star , so may be it is deadly , but there can be other conditions which mitigate this problem. And for other stars like A and more likely F stars the UV problem is not that much.

fl1pper
2009-May-06, 11:15 AM
Hi from another newbie,

Have a look at the lectures at:

http://academicearth.org/courses/introduction-to-astrophysics

Several of these deal with how extrasolar planets are found and is a good series of lectures in general.

cheers

andy

Wizard From Oz
2009-May-06, 03:02 PM
Rigel star is an extreme example ! Only 0.13% of stars belong to this type. It is 40,000 times brighter than the sun , or 66,000 if you count UV. Yes there is more UV in its spectrum than in our own star , so may be it is deadly , but there can be other conditions which mitigate this problem. And for other stars like A and more likely F stars the UV problem is not that much.

I was just trying to clarify for the OP that just because we find a planet orbit a star in the right position, the type of star is going to play a role in what we might potentially find out about that planet

In terms of finding potential life bearing planets. There are more than enough F and G class stars out there to keep dedicated planet hunters busy for a very long time

Obviously right now we are looking at virtually every star so that we can refine techiques and build up data points for how best to find planets, but I suugest as time goes on, the search will narrow to systems that have more potential to produce Earth like planets with Earthlike evironments

Sticks
2009-May-06, 03:47 PM
Hi from another newbie,

Have a look at the lectures at:

http://academicearth.org/courses/introduction-to-astrophysics

Several of these deal with how extrasolar planets are found and is a good series of lectures in general.

cheers

andy

fl1pper

Your post was held in moderation because as a newbie you included a link. This board automatically does this when a poster has less than a certain number of posts.