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Old 07-November-2003, 08:09 PM
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For most of us who has been talking about space travel these last few months, this following little senerio should prove to be both fun and thought provokitive. <_<

Suppose the space faring governments pooled resources and developed a real (per say) starship. <_< \
It is capible of velocities of up to five and one half times the speed of light, and can carry a couple hundred passengers. Best of all, they are looking for ordanary people for the voyage to other stars. :P
Would you go?

Now before clicking that post message and typing, "yes in a New York minute" really think about what this would likely entail. :unsure:

This journey will take the rest of your life and still not be complete. Although you will get to visit at least a few stars before you die, it will take years, and for some of the little bit farther ones, decades to get to them.
Those you leave behind you will never see again. While communications with Earth and loved ones there will be allowed and even encouraged, it will be corrispondance much like snail mail. :blink:

Never again will you see a snow capped mountain, run through a forest, or prarie, and smell the fresh air, such as you have here. No riding in a car, snuggling next to a warm campfire, or fireplace. No vacations. :huh:
No telephoning who ever you want, when ever you want. No more internet such as you know today.
No freedom to wear whatever clothing you want, or run naked through your home if you so desire.
Your selection of life mates will be limited to those on the ship, unless you are currently married and take your spouse with.
Would you go?

Procreation will be an absolute requirement. B) But you can't have a lot of children either.
You will have to either be of child bearing capibility, or at least willing to contribute to the ship's gene pool by whatever means technology on the ship provides.
Your choice of medical care will be limited to the staff on the ship. No selecting your own Primary Care Physian. No 2nd opinions, and no disputing doctor's instructions. h34r:

Any family members who go with have to do so by their own free will, and be in good health without defects which would place a burdon on the starship mission or your abilities to fulfill your duties.
No one with genetic handicaps such as downs syndrome or sickle cell will be going on the trip, however, if such are born on the ship is another matter and will be dealt with case by case. h34r:
It is also entirely possible your significant other will not accompany you on the voyage, either because of lack or willingness, or health will not allow, or inability and/or unwillingness to procreate in order for succeding generations to continue the journey. :angry:
Would you go?

The ship will have provisions to last 300 years for the number of people on the ship at launch. B)
A means of artificial gravity is in use, and the danger of radiation or other contamenents from operations of the ship are miminal. Living quarters will be provided for families, and couples. Single people will have a same gender barracks like living environment until they select a life mate or spouse of the opposite gender.
Recreation facilities will be included on the ship, but the selection will not be so unlimited as on Earth.

Finally, you will have a say as to where the ship can go and what to explore with the following limitations.
Maximum speed is five and one half times the speed of light. It will take a full week to reach maximum speed. As you near a destination, deceleration to managaible orbital or exploration speeds from full speed will take a full month.
Your range is generally limited to around 500 light years from our solar system. Because a direct return trip for whatever reason should not take much more then a single human life span.
Missions to real and present dangers must maintain a safe distance.
For example, if a black hole is discovered, get no closer then absolutly neccesary. Or a visit to the red supergiant varible star Betelguise be under extreame caution because of the possibility of that star going supernova with little or no notice.
Other limitations not thought up before as may arise must be dealt with via common since.

Now, would you go? and if so where, and what would you want to explore?

I'm hoping to hear a big varity of replies, and hopfully this string will be at least as interesting and as much fun as the favorite planet or moon string has been.

Enjoy. Thus saith the Planetwatcher.
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Old 07-November-2003, 08:50 PM
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No, not for that long. If we could reduce the round trip to a couple of years though.
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Old 07-November-2003, 10:21 PM
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A mere 500 light years? I'd like to go to the Orion Nebula, but of course thats 1500 light years away...
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Old 08-November-2003, 03:39 AM
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The Pleiades... I believe that's within reach
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Old 08-November-2003, 03:41 AM
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I'll go anywhere you like as long as we can stop at 7/11 on the way.
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Old 08-November-2003, 09:41 AM
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If this was my only chance at an interstellar journey, then I would take it. Sadly I'm not sure exactly what stars or objects would be in reach of 500 lightyears...
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Old 09-November-2003, 02:16 PM
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I would sign up! I had been saying traveling with teenagers is a terrible fate, but I would hope they would want to go with me. I'm not sure how many years we could stand "Are we there yet?"

Any chance of 'cold sleep' or suspended animation?

I would first want to check out our next door neighbors at Alpha Centuri, then I'd just be along for the ride.
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Old 09-November-2003, 02:21 PM
Haglund Haglund is offline
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Other good destinations would be Sirius, Vega and the sol-like stars Tau Ceti and Epsilon Eridani.
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Old 09-November-2003, 09:21 PM
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Let's see I read somewhere that there are 1,000,000 stars within 500 lightyears of Sol. I guess I'm going to have to do some research for make my final list.
but for starters:

Alpha Centauri - its the closest. Wolf 359 because I'm a star trek fan, and last but not least Pleiades which is 500 light years away. Though I'm not sure if they are all going in the same direction. I hope it doesn't matter.
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Old 11-November-2003, 10:53 PM
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Quote:
Originally posted by Polly V@Nov 9 2003, 09:21 PM
Alpha Centauri - its the closest. Wolf 359 because I'm a star trek fan, and last but not least Pleiades which is 500 light years away. Though I'm not sure if they are all going in the same direction. I hope it doesn't matter.
The Pleiades (M45) is an open cluster, and a relatively young one at that, so the constituent stars should have a common proper motion.

I'm not sure that visiting young stars would be all that interesting other than for astrophysical research. Little or no chance of life and a lot radiation.

Dave Mitsky
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Old 12-November-2003, 04:55 AM
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I think Polly V meant that she (?) wasn't sure if alpha centauri and the Pleiades were in the same direction ... not if the Pleiades cluster were moving in the same direction.

Personally I'd like to fly out of the plane of the galaxy. Hopefully far enough to see the shape of it from above or side. That'd be pretty spectaculat. would 500Light years be enough for that?
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Old 12-November-2003, 08:51 PM
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I would be at a loss myself to decide where to go first.
It would be between Alpha Centauri, and Epsolin Erideni, which are pretty much opposite directions. To know where the stars are would likley help. So I'll try to explain the few closest.

Looking at our Solar system from some distant point to celestrial north, or toward Polaris, imagine a clock for positions.

At 12:00 would be Sirius. Between 12 and 1 is Procyon, and Kaptens Star.
Near 2:00 is Epsolin Eri. At 3:00 would be Tau Ceti (also known as UT Ceti)
Near 5:00 is Ross 248 (I think, one of the Ross stars for sure)
Between 6 and 7 is Barnard's Star.
Between 8 and 9 is Alpha Centauri
At 10 is Wolf 359 and Lalande (forgot that number again)

Now looking at it from on plane is different.
Alpha Centauri and Barnard's Star is below the Celestrial Equator, and the rest are above.
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Old 12-November-2003, 10:50 PM
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Quote:
Originally posted by Josh@Nov 12 2003, 04:55 AM
I think Polly V meant that she (?) wasn't sure if alpha centauri and the Pleiades were in the same direction ... not if the Pleiades cluster were moving in the same direction.

Personally I'd like to fly out of the plane of the galaxy. Hopefully far enough to see the shape of it from above or side. That'd be pretty spectaculat. would 500Light years be enough for that?
Alpha Centauri lies well south of the celestial equator. Wolf 359 is located in Leo, a spring constellation that lies along the ecliptic. The Pleiades are also near the ecliptic but appear in the late fall sky in the opposite direction. These destinations are, in fact, widely separated in direction.

Considering that the Milky Way has a diameter of about 100,000 light years and is several thousand light years thick I doubt that a position 500 light years above or to the side of the plane of the galaxy will afford a very good perspective.

Dave Mitsky
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Old 12-November-2003, 11:41 PM
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Well bugger that idea then. That's it, I'm not going.
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Old 14-November-2003, 12:50 AM
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How about alpha centauri. That is the closest star to our solar system
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Old 14-November-2003, 02:22 AM
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Solstation.com, If your computer is Java enabled, this is your virtual Tourist Brochure.
The Orion Arm, for a more distant demonstration of our neighbours.
If I were to suggest a journey, A slight detour to those journeying on to the Pleiades, May I recomend a stop over at the Hyades cluster ? please find inclosed 3d movie
The Orion Arm, for any more questions please do not hesitate to contact me
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Old 14-November-2003, 06:44 AM
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I would like to go to a black hole or neutron star, but not too close!
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Old 14-November-2003, 06:58 PM
Polly V Polly V is offline
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Well thanks fellas, for that information. And may I say Dave, that you are a fountain of information.

I'm going to have to research this journey in much greater detail.
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Old 15-November-2003, 02:16 AM
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This was a really tough question to answer honestly. I think that, once we we're capable of launching one colony ship, that others would follow. With mechanation and an increased birth rate, humans would quickly set up colonies on any habitable planet. Some would do it for adventure, some for profit.

Would I want to be on one of the first ships out? Probably not, but I'd certainly be willing to invest in some of it - owning part of a colony would be really cool. But, once a 'ring' of colonies formed around earth, I'd be quite interested in moving to one of the more successful ones.
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Old 15-November-2003, 10:09 AM
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Ahh, it would also be intresting in going to a colony not as succesful and making it successful. Imagine what you could create, and own!
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Old 15-November-2003, 01:15 PM
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Okay folks, check out this link.
http://antwrp.gsfc.nasa.gov/apod/ap010318.html

If I pasted this correctly, you will get a little diagram of the 25 nearest star systems. Thought this might make a good reference of how the nearest star systems are positioned in relation to us.
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Old 16-November-2003, 04:36 AM
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Quote:
Originally posted by quizzler2@Nov 14 2003, 12:50 AM
How about alpha centauri. That is the closest star to our solar system
Well, actually alpha centauri is the second closest star to our solar system.

Proxima centauri is the closest :-)

Even still, i would imagine it would be quite boring.

I would prefer to visit an extra-solar planet where i could possibly find something other than another enormous ball of gas.


-Josh
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Old 16-November-2003, 12:22 PM
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I've read that Proxima is orbiting the Alpha Centauri A and B, but in a very wide and slow orbit?
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Old 16-November-2003, 08:31 PM
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Not entirely accurate.

Alpha Centauri A and Alpha Centauri B form a binary system at 4.35 light years from the Sun. Proxima Centauri is only 4.22 light years from the Sun and could well not even be bound by the other two stars.

Chances are in a hundred million years or so it will leave that system.


-Josh
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Old 16-November-2003, 09:18 PM
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Not entirely acurate either.
Although Joshes distances are correct, and the Alpha Centauri is called a binary system, although it is actually a trinary system. :huh:
Proxama Centauri is actually Alpha Centauri C, but it is called Proxama Centauri because it is a little closer then the other 2 Alpha Centauri stars which are so close to equal distances, that the differences are almost unmeasurable from our perspective.

Alpha Centauri properly refers to all three stars, unless you are refering specificly to star C as Proxama, in which case the other two are refered to as Alpha A and Alpha B. The whole system is also known as Rigil Kentaurus.

Finally it may well be that there are planets in the system, because there has been much speculation of that before. It is even remotely possible that there is a forth star which is a brown dwarf.
But the general conscenses has been that if there are indeed planets they are perpendicular to the orbital plane which would allow us to visually see them cross the disk of the parent star. And such planets, and or a brown dwarf are too small for us to detect any perturbsion of one or more of the main stars.

There has been further speculation although no proof yet that others of our nearest stars may have planets, the most noteworthy of these are Lalande 21155,
Barnard's Star, Tau Ceti, and Luyten 759. B)

The nearest star known to have planets is Epsilon Eridani which is almost the exact opposite direction as Alpha Centauri.

I'd be happy to visit any or all these stars listed, although the journey itself would be very boring as AusJosh eluded to. :P
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Old 17-November-2003, 07:26 AM
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Well, without wanting to start an argument....i have more to say.


I did not specifically mention its a trinary system because as far as i am conerned. It isnt. Alpha A and Alpha B are a binary system. Alpha C (only so named because of its position in the night sky) is not nessecarily part of that system and (as i stated in my original post) could well fling off into the distance in a million years or so (could just be a passing star).

Although i guess we will know in about 250,000 years or so to see if it actually orbits the CoM of "the system".

:huh: :huh: :huh: :huh:






-Josh
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Old 17-November-2003, 11:44 PM
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Well I really wouldn't want to go for that long of a journey. Though I would like to go to Tau Bootis. After all NASA says it has a blueish-white planet in orbit around it.
Which means it could have life. Andn I think finding life would be worth the journey.
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Old 22-November-2003, 09:27 AM
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Sign me up. ^_^ I'll go like a shot. I'm not bothered where to either. :angry:

It doesn't matter how long the journey is, or how boring it is. Getting as far away from this planet as possible, as soon as possible is much better than hanging around here with Dictators, Tyrants, Radicals and Fanatics.

But, thinking about it, why would any lifeform from another planet welcome us with open arms? After all, there are people on this planet who get great enjoyment out of causing harm to their fellow humans. That makes us really attractive-NOT.

No wonder we've never been visited by beings from other planets.
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Old 18-December-2003, 04:08 AM
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Quote:
Originally posted by Planetwatcher@Nov 16 2003, 09:18 PM
Not entirely acurate either.
Although Joshes distances are correct, and the Alpha Centauri is called a binary system, although it is actually a trinary system.    :huh:
Proxama Centauri is actually Alpha Centauri C, but it is called Proxama Centauri because it is a little closer then the other 2 Alpha Centauri stars which are so close to equal distances, that the differences are almost unmeasurable from our perspective.  

Alpha Centauri properly refers to all three stars, unless you are refering specificly to star C as Proxama, in which case the other two are refered to as Alpha A and Alpha B.  The whole system is also known as Rigil Kentaurus. 

Finally it may well be that there are planets in the system, because there has been much speculation of that before.  It is even remotely possible that there is a forth star which is a brown dwarf.    
But the general conscenses has been that if there are indeed planets they are perpendicular to the orbital plane which would allow us to visually see them cross the disk of the parent star.  And such planets, and or a brown dwarf are too small for us to detect any perturbsion of one or more of the main stars.

There has been further speculation although no proof yet that others of our nearest stars may have planets, the most noteworthy of these are Lalande 21155,
Barnard's Star, Tau Ceti, and Luyten 759. B)

The nearest star known to have planets is Epsilon Eridani which is almost the exact opposite direction as Alpha Centauri. 

I'd be happy to visit any or all these stars listed, although the journey itself would be very boring as AusJosh eluded to. :P
Hi everyone, I'm new to this most interesting forum. Just a few words.

With minor qualification, Both AusJosh and Planetwatcher are right on Proxima. What do I mean by that? Well, the status that is Proxima and its relationship to the Alpha Centauri AB pair has NOT been resolved to the satisfaction of all astronomers as YET.

Anosova et al. 1994, were the ones who first proposed that Proxima's apparent proximity to the Alpha Centauri AB pair could be NOTHING more than a CHANCE ALIGNMENT although ALL the three aforementioned stars along with ADS 10288 trinary; the binaries, Gliese 140.1 and 676 and several other single stars appears to be part of a nearby stellar moving group based on radial velocity and proper motion measures.

I must make it clear that WIDELY separated binaries and multiples like the proposed Alpha Centauri triplets are NOT rare occurances.

NATURE & SEPARATIONS OF DOUBLE AND MULTIPLE STARS
Duquennoy & Mayor, 1991 (hereinafter DM91); Latham et al. 1984 & Wassermann et al. 1991, have found that at least 60% of stars are either binary or multiple in nature, some actually claim that ALL stars were at one time or another, part of some kind of binary or multiple systems. Of them all, Wassermann et al., 1991 went the furthest in suggesting that the traditionally suggested cut-off maximum separation of 0.1 pc is really the result of observational bias and other limitations.

The implication of their research is that in reality, there could be binaries and multiples that are separated by as much as 1 pc.

Now let me also take the opportunity to address a long-standing controversy over whether our very own Sun can support a remote, ULTRACOOL, VERY LOW MASS (VLM), DIM companion with a separation up to projected distance of Proxima from the Alpha Centauri AB pair.

THE SUN'S GRAVITATIONAL POTENTIAL WELL: CAN OUR SUN SUPPORT A REMOTE COMPANION?

As we know, the potential of the Sun is calculated from Newtonian gravity, except very close to the Sun where general relativistic effects may be significant for sensitive experiments. By Newtonian theory, the potential of a mass M at a distance r is given by -GM/R where G is the gravitational constant. By definition, the potential is zero at r = infinity. Hence the potential well of the Sun extends to infinite distances. However, the effect of Sun's gravity is not unlimited due to the presence of other masses in our galaxy.

Thus the gravity of the Sun extends to the Oort cloud. It is postulated to extend for a couple of light years even. The gravity well of the Sun will end when its gravity at a certain point in space equals the gravity from another star. At any point further than that point, the gravity well of the other star will be deeper than that of the Sun so that a particle at that point will be in orbit around the other star rather than the Sun. For instance, imagine that the Alpha Centauri system has a single star of the mass of the Sun (in reality it comprises of three stars). Then, the Sun's gravity will extend exactly to half the distance to this star.

With regards to the potential of Proxima being "ejected" from the Alpha Centauri system one day (assuming that all 3 are indeed part of a bound system), the reseraches of DM91; Latham et al. 1984 & Wassermann et al. 1991 do NOT lend much support to such a proposition. i.e. UNLESS the neighborhood around Alpha Centauri is a CHAOTIC one with massive stars (singles, binaries or multiples), Giant Molecular Clouds and othe exotic celestial bodies (e.g. solar mass black holes) on a collision or orbital disruption course with the Alpha Centauri system - ALL of which are NOT present , it is forseeable that Proxima will remain a bound member for a long long time to come.

ON PLANETWATCHER'S "4TH COMPONENT IN THE ALPHA CENTAURI SYSTEM"
His/Her suspicion are based on findings by Schultz et al 1998, who from preliminary Hubble Space Telescope (HST) images, thought they saw something whose implied luminosity suggests a substellar Brown Dwarf (BD) nature and a projected semimajor axis of 0.5 AU (around Proxima) and an orbital period equals to a year. HOWEVER, Schultz and his fellow collaborators were NEVER able to repeat the observations and subsequent investigations (via interferometric astrometric and radial velocity measurements) by Benedict et al 1999 RULES OUT companions with masses >0.8 MJup having an orbital period around Proxima Centauri of between one and about 2.7 years.

ELABORATION
P = Orbital period = a^1.5/sqrt(Mstar+Mbd) years ------ Equation (1)
Substituting P = 1 year; a = 0.5 AU; Mstar = Mass of Proxima = 0.123 Msun into Equation (1), we have,
P = 0.5^1.5/Sqrt(0.123 + Mbd)
1 = 0.35355339/Sqrt(0.123 + Mbd)
Sqrt(0.123 + Mbd) = 0.35355339
0.350713558 + Sqrt Mbd = 0.35355339
Sqrt Mbd = 0.35355339 - 0.350713558
Sqrt Mbd = 0.002839832259
Mbd = 0.053290076 Msun
Mbd = 55.78629593 MJup
Where a = Semimajor axis; Mstar = Mass of Star; Mbd = Mass of proposed BD companion (expressed in solar masses); Msun = Mass of Sun; MJup = Mass of Jupiter and Sqrt = Square Root

Using the measurements derived from ESO* observations and assuming them to be correct, according to the BD evolutionary model of Burrows et al. 1997, the Effective Temperature (Teff) of a 4.85 Gyrs old (assuming coevality), 55.78629593 MJup Alpha Centauri IV (i.e. the proposed BD companion to Proxima) would be 888.623 °K (implying a Spectral Type (SpT) of ~T5 i.e. a "methane" dwarf in the mould of GL 229B, Epsilon Indi Ba and Epsilon Indi Bb) with a surface gravity of 2.06529 * 10^5 cgs; a radius of 58533.1 km; and a luminosity (Solar Luminosity) equals to 4.00169 * 10^-6. Relying on the predicted Teff and luminosity alone, such a MASSIVE and relatively "BRIGHT" substellar companion, it is therefore concluded that UNLIKELY the plethora of Infrared missions and surveys (both ground and space-based ones) would have missed it.

BTW, ANY planet or planets that may or may not be orbiting ANY of the 3 known components of the Alpha Centauri system need NOT have to necessarily be on perpendicular or near perpendicular orbits around their cnetral primary. BUT of course, the Kozai Mechanism can be a crucial factor in limiting the long term survival of such highly inclined orbits. Roughly speaking, for the central AB pair, the critical semimajor axis (i.e. defined here as the maximum possible semimajor axis of the outermost planet) is <5 times that of the CLOSEST approach of either of Alpha Centauri A or Alpha Centauri B.

*
http://www.eso.org/outreach/press-rel/pr-2...3/pr-05-03.html

Parameter
Alpha Cen A Alpha Cen B Proxima Sun Unit
Age 4850 4850 4850 4650 million years
Mass 1.100 0.907 0.123 1.000 solar mass
Radius 1.227 0.865 0.145 1.000 solar radius
Temperature 5790 5260 3040 5770 Kelvin
Luminosity 1.519 0.500 0.000138 1.000 solar luminosity
Hydrogen 71.5 69.4 69.5 73.7 percent
Helium 25.8 27.7 27.8 24.5 percent
Heavier
elements 2.74 2.89 2.90 1.81 percent

REFERENCES:
Anosova, J., Orlov, V. V. and Pavlova, N. A., 1994, "Dynamics of nearby multiple stars. The alpha Centauri system", A&A 292, p. 115-118

Benedict, G. F., McArthur, B., Chappell, D. W., Nelan, E., Jefferys, W. H., van Altena, W., Lee, J., Cornell, D., Shelus, P. J., Hemenway, P. D., Franz, O. G., Wasserman, L. H., Duncombe, R. L., Story, D., Whipple, A. L., & Fredrick, L. W., 1999, "Interferometric Astrometry of Proxima Centauri and Barnard's Star Using HUBBLE SPACE TELESCOPE Fine Guidance Sensor 3: Detection Limits for Substellar Companions", AJ 118, pp. 1086-1100

Burrows, A., Marley, M., Hubbard, W. B., Lunine, J. I., Guilliot, T., Saumon, D., Freedman, R., Sudarsky, D., & Sharp, C., "A Non-Gray Theory of Extrasolar Giant Planets and Brown Dwarfs", 1997, ApJ 491, pp. 856-875

Duquennoy A., & Mayor M., 1991, "Multiplicity among solar-type stars in the solar neighbourhood. II - Distribution of the orbital elements in an unbiased sample", A&A 248, 485-524

Latham, D. W., Tonry, J., Bahcall, J. N., Soneira, R. M. & Schecter, P., 1984, "Detection of binaries with projected separations as large as 0.1 parsec", ApJ 281, L41-45

Schultz, A. B., Hart, H. M., Hershey, J. L., Hamilton, F. C., Kochte, M., Bruhweiler, F. C., Benedict, G. F., Caldwell, J., Cunningham, C. & Wu, Nailong, 1998, "A possible companion to Proxima Centauri", AJ 115, pp. 345-350

Wasserman, I., & Weinberg, M. D., 1991, "Wide binaries in the Woolley catalog", ApJ 382, p149-167


LEGEND:
1 parsec (pc) = 3.26162 Light Years (L.Y.)
1 L.Y. = 63,240 AU
1 AU = 149,600,000 km (i.e. Earth's average distance from the Sun)
° K = ° C + 273
° F to ° C
To convert Fahrenheit to Celsius (Centigrade), subtract 32 and divide by 1.8
° C to ° F
To convert Celsius (Centigrade) to Fahrenheit, multiply by 1.8 and add 32

SOME USEFUL RESOURCES:
For retrieval of abovereferenced papers (e.g. DM 91), one can search and find them at places listed below,

http://adsabs.harvard.edu/abstract_service.html
http://adsabs.harvard.edu/bib_abs.html


Hope this helps!
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  #30 (permalink)  
Old 18-December-2003, 05:22 AM
rajasun rajasun is offline
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Join Date: Dec 2003
Posts: 41
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Personally, I would LOVE the ooportunity to explore the Edgeworth-Kuiper Belt, the Scattered Disk, the Oort Cloud i.e. the 3 dimensional space in between here and Proxima Centauri. REASON: to unravel once and for all, the TRUE census in the immediate solar neighborhood of all the MAJOR objects (substellar BDs; substellar mass clouds; and planets) that may as YET be unaccounted for.

:unsure:
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