So… does Alpha Centauri have any planets?

A short follow-up on this post I made a while ago (note the tantalising difference in wording of the title).

Just today, I stumbled across a scientific paper, thanks to a tweet by @b0yle, that outlines the priority of stars to which to send an as-yet-hypothetical interstellar mission (link here; the paper is not as jargon-laden as a lot of other scientific publications, so go read if this subject interests you).

Short answer: we still don’t know. And with our current techniques, we can’t be certain. We’re getting very close, though.

Some figures: there are 56 stars within 15 light years of us (give or take a few that may or may not be within this range and possibly very dim ones we haven’t yet discovered).

Most of those are M-class stars, ‘red dwarfs’. There are also 2 G-class stars, like the sun (Alpha Centauri A at 4.4 ly and Tau Ceti, at 11.9 ly). According to current evidence, up to 30% of all stars may have planets. At this point in time, most discovered planets have been very large.

The fact that we haven’t detected any in the Alpha Centauri system doesn’t mean that there are none.

Planet size is expressed in number of times the planet is heavier than Jupiter. It is still fairly hard to detect anything significantly smaller than that. Yet evidence suggests that smaller planets could be more common than larger ones.

Alpha Centauri is a star system of three stars (one K-class, one G-class–like the sun–and one M class). What is the statistical chance that none of them will have planets?


9 comments on “So… does Alpha Centauri have any planets?

  1. Alpha Centauri A has at least 4 planets size of Earth or little bigger orbiting just like 4 moons orbiting Jupiter. And Alpha Centauri B may have 2 planets size of Earth and 2 planets size of Mars.

  2. One of this planet is called ACART.
    The Acart planet around Alpha Centaury have two moons.
    It is size of the Earth very similar. The climate is very cold, day last for 46 hours and year last for 353 days.
    What is breaking is that is inhabit with human life forms very similar to homo sapiens, 23 billions of them on planet, and they are technologically and spirituality few hundred years advanced than we are.

    They reached space flight and are able to visit Earth with cryostasis.
    Look at Berlet story.

  3. Alpha Centauri and its stellar companions would be a great place to put a few generation ships. Though I think its more probable that we’re going to develop our own star system before taking on the frontier beyond the Oort Cloud. If we can get to LEO with the same amount of weight a fully loaded tractor trailer @ the cost of a trip to New York from California…. will have the solar system wrapped up in less than 150 years. I think we could have an advanced cubesat mission with lasersails ready in 30 years

  4. OK, people, there have been a few replies to the comments above that, although I agree with them, are inflammatory and I have disallowed them for that reason only. I will have no name-calling on this blog.

    No one has any proof that planets exist at Alpha Centauri. If such proof emerges, I expect to see it in scientific papers and official announcements, since it would be a major discovery.

    If you are of the opinion that all scientists conspire against the general public and keep information of that nature a secret, you’re at the wrong blog.

  5. Pingback: Alpha Centauri DOES have planets! « Must Use Bigger Elephants

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