Comments on: If Alpha Centauri Has Earth-Like Planets, We Can Detect Them

By: Anthony B Austin

Anthony B Austin — Mon, 02 Mar 2009 20:55:58 +0000

Re Centaurian planets. In 1989 I authored a book
with Brian Crowley (1938-2008) called "Return to
Mars". In this work we showed
that the Icelandic Eddas (stories) said there
were planets orbiting both alpha Centaurus A and
B, stating that the one inhabitable world of B is
called Fjalar. The book was republished by Black
Rabbit Press in 2003. In the time elapsed, 14
years, we thought that astronomy would confirm
or deny our findings. Nobody did.
We assume that the truth is scientifically
unpalatable and an inhabitable world 4.3 ly away
is too terrifying to contemplate.
Anthony B Austin

By: psychonaut

psychonaut — Fri, 28 Nov 2008 04:58:19 +0000

Small, rocky worlds like the ones they are talking about do not have enough mass to affect the star in any observable way even if they are orbiting our nearest neighbor.

By: psychonaut

psychonaut — Fri, 28 Nov 2008 04:53:54 +0000

The reason they can't detect planets around our nearest neighbor is that they can only detect gas giants around stars within a 300 ly or so radius from Earth. They cannot see the planets, they can only see the gravitational effect of a planet as it pulls on a star and causes it to "wobble". Since Alpha Centauri A & B are so close it is probably the case that gas giants did not have room and/or matter enough to form. After all, if Jupiter had gathered more matter early on, we might be living in a binary system.

By: Tobias Holbrok

Tobias Holbrok — Fri, 31 Oct 2008 20:41:36 +0000

Planets aren't cpnsidered likely so no-ones bothered looking?

A lot stranger things have happened….

By: Tim Staffell

Tim Staffell — Fri, 31 Oct 2008 18:32:30 +0000

Pretty inconclusive collection of opinions, as regards why planets havent been searched for around Centaurus…What am I being asked to accept? that it's easier to detect a planet orbiting a star in excess of a hundred light years away than around our nearest neighbour? that it would take 5 years with a dedicated 1.5 metre telescope to turn up any answers. I find that very difficulty to accept. This has puzzled me for some time. Surely the nearest star has got to be the best choice for observation, hasn't it? And if not, why not? something's not right here….

By: Sam

Sam — Sat, 05 Apr 2008 06:03:24 +0000

As far as I know, Proxima Centauri is so far away from the other Alpha A and B that it might have little influence on planet formation around either A or B. Also, if I remember correctly, B is about as far from A as Neptune is from Sol. So it seems to me that its possible, albeit unlikely, that either A or B might have terrestrial planets. At any rate, it does make sense to scrutinize the Alpha Centauri system to the best of our abilities since it is so close. Living planets or not, I'm sure it will prove an interesting game of cosmic billiards.

By: googajoob

googajoob — Sun, 16 Mar 2008 01:15:04 +0000

i would nt be suprised at all if they find some small rocky worlds . i doubt even so when seti turns it attention to them any sign of intelligent life will be found . lets just say it would be a miracle if it is and slighly disturbing because if they were advanced enough it would nt be totally out of the bounds of possibilty that they could get here .

By: Willem Jan Triel

Willem Jan Triel — Sun, 16 Mar 2008 00:07:46 +0000

Well, i will make it short, have no desire to do a long story to explain but i have a Good feeling about it, that they will find some habital planets with life around Alpha Centauri A. Let me say this, it will no surprise me.

By: Alpha Centauri May Have Earth-like, Habitable Planets | MeltedCube

Alpha Centauri May Have Earth-like, Habitable Planets | MeltedCube — Sat, 15 Mar 2008 23:38:34 +0000

[...] If Alpha Centauri Has Earth-like Planets, We Can Detect Them [Universe Today]Nearest Star System Could Harbour Earth Twin [Space.com] [...]

By: Alpha Centauri May Have Earth-like, Habitable Planets | MeltedCube

Alpha Centauri May Have Earth-like, Habitable Planets | MeltedCube — Sat, 15 Mar 2008 23:38:34 +0000

[...] If Alpha Centauri Has Earth-like Planets, We Can Detect Them [Universe Today]Nearest Star System Could Harbour Earth Twin [Space.com] [...]

By: mystic.smeg

mystic.smeg — Thu, 13 Mar 2008 08:22:13 +0000

Statistically, it's unlikely that there are planets; unlikely [x2] it would be earth sized; even more unlikely [x4] it would fall within a habitable zone; even more unlikely [x8] it would have an oxygen/nitrogen atmosphere or be of a similar composition to our own Earth.

Metaphorically, if they find Earth [2] in orbit 4.3ly away, my bag is already packed…

By: Near neighbours? « Mr Wever’s Blog

Near neighbours? « Mr Wever’s Blog — Thu, 13 Mar 2008 01:32:12 +0000

[...] Published March 13, 2008 Uncategorized Reports here andÂ here (summarised really well, as always, by Wired here) of intriguing results from some [...]

By: TJ

TJ — Wed, 12 Mar 2008 21:55:30 +0000

I'll go out on a limb and predict that by the time we visit a Cent., the number of people inclined to prophesize will have dramatically decreased.

By: tacitus

tacitus — Wed, 12 Mar 2008 06:46:07 +0000

I will go out on a limb, based on obscure and unscientific philosophical grounds, and prophesy that we will find an Earthlike planet at Centaurus A with an oxygen-nitrogen atmosphere, liquid water, and in the habitable zone.

We'll let you get away with this nonsense if you don't come back here expecting credit if we do indeed find a Earth-like planet. Anyone can make a prediction based on whimsy and speculation (or even less, as in your case). And sometimes they will even guess right.

By: David

David — Tue, 11 Mar 2008 23:28:35 +0000

Send someone on a one way mission to find out…

By: David

David — Tue, 11 Mar 2008 21:57:14 +0000

Regarding the Proxima question, it orbits very far around the barycenter and is small enough so that it wouldnt disrupt either A or B's system, other then throwing Oort or Kuiper type objects in

By: Scott G.

Scott G. — Tue, 11 Mar 2008 19:31:34 +0000

Current solar system development models suggest that stable habitable zones can exist around binary stars given certain starting conditions (and not very strict ones, either). See http://www.centauri-dreams.org/?p=1137 for a blog entry on the topic or Google "Nader Haghighipour," "terrestrial planets" and "binary stars" for a variety of links.

By: John Mendenhall

John Mendenhall — Tue, 11 Mar 2008 16:50:21 +0000

Many of questions posted so far are answered by the proposed program. The sooner it starts, the better.

I will go out on a limb, based on obscure and unscientific philosophical grounds, and prophesy that we will find an Earthlike planet at Centaurus A with an oxygen-nitrogen atmosphere, liquid water, and in the habitable zone.

By: Alpha D. Camara

Alpha D. Camara — Tue, 11 Mar 2008 15:50:23 +0000

I think that the question of planets around the Alpha Centauri System would be a little more complicated because if I remember correctly this ia tripple star system. Are you guys forgetting about the effects that Proxima Centauri may have on such planets? If anyone has an idea please, let me know. Thanks.

By: Simon

Simon — Tue, 11 Mar 2008 11:49:36 +0000

I reckon having a 1.5m telescope pointed at Alpha Centauri for 5 years would be a perfect task for a liquid mirror telescope! Low cost, no need to tilt it, why, I might even try making one myself!

By: Andrew

Andrew — Tue, 11 Mar 2008 08:34:29 +0000

QeV and spaceman

You bring up some interesting points. Qev example of Gamma Cephei is one that has caused much controversy. In this case, this was reported in 1988 and 1989, but was late retracted. In 2002, the observations were repeated restating the case of the existence of the companion. Yet in 2007 there still remains doubt of the results, as the current period alleged by the Hatzes et al. (2003)
Others like Schneider (2005) and NeuhÇŽuser et al. (2007) have also been questioned, and in dynamical evolution has been challenged. Ie. Castro (2007) and Solovaya and Pittich (2007), who found the orbits of these companions as being unstable being so-called "dynamically full".
I think the problem is with interpreting the spectroscopic or indirect methods like radial velocities, especially the latter, as they are far more subjective in binary systems because of the quality of the observations. There is also some evidence that the red dwarf in Gamma Cephei might have been captured and not formed with the primary.
Another important system was Iota Horologii, but this also has been since retracted.
As a comment, the difficulties with binaries is that there are other factors when detecting the behaviour of exo-planets around stars that cannot be explained without also eliminating the effects of the companion star(s).
I think this work on Alpha Centauri is important as the possibility of detecting planets because of its proximity.
However, the existence of planets around binary star system are an interesting problem. No doubt in time this might be proven to be true, but at the moment confirmation of exp-planetary still is in early days.
At present. 15 binary stars are suspected to have planets, but all suffer from the problems eliminating the effects of companions stars.
I've read quite a few reports and current investigation being undertaken at the moment, but few have shown exo-plants exist. The most interesting aspect in the last year is the discovery of dust rings surrounding some binary systems, hich are unexpected – yet till now no planets have been yet confirmed within the large dust disks.
(Read http://www.spacedaily.com/reports/NASA_Telescope_Finds_Planets_Thrive_Around_Stellar_Twins_999.html

This article was written a little less than a year ago (30 March 2007)

Anyway, thanks so much for pointing out these examples.

Andrew

By: spaceman

spaceman — Tue, 11 Mar 2008 05:02:42 +0000

Andrew,

You are wrong about there being no planets found around double stars. Actually, even though RV searches are biased in that they preferentially look at single stars they nevertheless found planets in double and even a triple star systems.

By: Qev

Qev — Tue, 11 Mar 2008 04:55:28 +0000

@Andrew

At least one planet orbiting a binary star system has already been found:

http://spaceflightnow.com/news/n0210/11planet/

By: Andrew

Andrew — Tue, 11 Mar 2008 00:48:11 +0000

One of the biggest problems with planets is how do they form around double stars. Surely there must be many serious issues in planetary formation. Ie. The destruction of any Oort like cloud by the two stars (meaning no water or ices available for Earth-like planets by comets), the significant effects of angular momentum changes in the systems formation, stability of planetary orbits.
Also as far as I know, NO exo-planets have been found around any double star.
I personally think that the chances of planets around 100AU apart or less double stars (as is Alpha Centauri) are very unlikely.

Note: Those here might like to read my own detailed webpages on Alpha Centauri at;
http://homepage.mac.com/andjames/PageAlphaCen001.htm

The true orbit;
http://homepage.mac.com/andjames/PageAlphaCen003.htm

And especially what Alpha Centauri would be like to a planetary observer around one of the stars and the issues of describing the night's sky.
http://homepage.mac.com/andjames/PageAlphaCen006.htm

Regards,
Andrew

By: Miguel V.

Miguel V. — Mon, 10 Mar 2008 23:15:22 +0000

Interesting post. Another key point is that Alpha Centauri A and B are very similar to our Sun (A is almost identical), therefore finding a similarly sized planet in that system in the habitable zone may have a big impact since it can really hold life.