Super-Earths With Super-potential Discovered Circling Star Gliese 667C

This artist’s impression shows the view from the extra-solar planet Gliese 667Cd looking toward the planet’s parent star Gliese 667C. Above center the more distant stars in this triple system (Gliese 667A and Gliese 667B) are visible and to the left in the sky, the newly discovered Gliese 667Ce can be seen as a crescent. A record three planets in this system lie within the star’s habitable zone.Credit: ESO/M. Kornmesser

Meet Gliese 667C, the little star with the big family. Gliese 667C resides near the “stinger” stars in the tail of Scorpius the Scorpion. You can even see it in binoculars on a clear night low in the southern sky. But it’s what you can’t see that makes this star so cool. It’s swarmed by at least six orbiting planets, three of them in the star’s habitable zone where liquid water might puddle on their surfaces.

This diagram shows the system of planets around the star Gliese 667C.  It’s the first found with a fully packed habitable zone. The relative approximate sizes of the planets and the parent star are shown to scale, but not their relative separations. Credit: ESO

Three of the six, Gliese 667 Cb, Gliese 667 Cc and Gliese 667 Cd, were found in the past year with Gliese 667Cc orbiting in the habitable zone. This week a team of astronomers using powerful telescopes in Chile and Hawaii announced the discovery of three more planets – Gliese 667 Cd, Ce, Cf – and possibly a fourth. All seven orbit closer to their host star than Mercury does to the sun. Heck, there are so many planets, they completely fill up all the orbital slots in the star’s habitable zone.

Another artist’s impression shows a sunset seen from the super-Earth Gliese 667 Cc. The brightest star in the sky is the red dwarf Gliese 667 C.The other two more distant stars, Gliese 667 A and B, appear in the sky also to the right. Astronomers have estimated that there are tens of billions of such rocky worlds orbiting faint red dwarf stars in the Milky Way alone. Credit: ESO

Three of them are super-Earths, planets more massive than our own but not quite as big as Uranus or Neptune. Because they circle a much cooler and less massive red dwarf star, they’re not lava-hot hells like so many other extra-solar planets but more temperate worlds where water could be stable. The Gliese system has the greatest number of super-Earths ever found in a star’s habitable zone to date.

You can use this map to help you find Gliese 667, located in the tail of the scorpion. The map shows the sky facing south around 11 p.m. from the northern U.S. The star will be higher up from the southern states. It shines at 6th magnitude and easy in binoculars. Stellarium

Gliese 667 lies just 22 light years from Earth and though it appears single in binoculars, it’s really a triple system. All the planets orbit the dimmest of the three dwarfs, Gliese C, which itself orbits in tandem with a tight pair of orange dwarf stars, Gliese A and B. A resident on any one of the new-found planets would look off toward the pair and see a bright double star shining day or night and providing about as much light as the full moon.

Water as always is key. Given their location, at least three of Gliese 667’s planets have the potential to support life.


10 Responses

  1. Aloha Astro Bob and Everyone!

    As always (well, except for that ONE time…just kidding!), this is another great article. Mahalo Nui Loa!

    As stated in your article, this “systems'” sun is 22 LIGHT YEARS AWAY, impossible for our species to travel there (as of this writing) and unlikely for “us” to go there any time in the foreseeable future. So why are we spending so much money on trying to find another planet for us to “live on”?

    Don’t get me wrong, this is about the ONLY thing our space “program” is doing that I can’t see the logic in spending so much money on. I’ve been an adamant supporter of our space program all my life, however, when this so-called “search for another Earth” started up and learning how far away any prospects/candidates really were, I began to doubt exactly WHY we are even bothering.

    I know we as a species benefited immensely from the space program almost immediately from the first manned missions of simply orbiting the planet all the way through the rover, Curiosity’s, exploration of Mars. I haven’t learned of many (if any) new beneficial developments from this never-ending search for another “habitable” planet as yet. This one endeavor seems to be a massive waste of dollars that could be used in other ways that could/would be a benefit of some sort to all mankind.

    Until we learn how to travel at speeds that are at or near (or even exceeds) light speed, all this searching seems to be a huge mission of futility. Of course I realize there are those that disagree with my opinion and that’s just fine, I understand.

    If I ignore the cost of this “search” for another Earth, then I have no problem(s) with doing this. It’s just that I believe the scientists and the effort (and money) involved in all of this could be used for something that is more attainable and useful for us as human beings and all living things on this planet.

    Again, this is just my very humble opinion. Sure, I find it interesting and all. It’s just something we can’t do even if we DO find a planet exactly like ours out there. Since any “habitable” planet, so far, seems to be light years away and human reproduction is IMPOSSIBLE in space (the process NEEDS gravity, constantly), I see this one “mission” as a total waste of time but mostly a waste (as HUGE waste) of money.

    Aloha For Now!

    1. astrobob

      I think the search for extrasolar planets has more to do with understanding more about the diversity of solar systems put there as well as figuring out if life could thrive elsewhere. I don’t mind investing a few bucks a year in search of new knowledge that broadens our perspective.

    2. “Desperdício”?! Desperdício é gastar 400-500 bilhões de dólares anualmente em armamentos e outras babaquices militaristas-nacionalistas, como o fazem, criminosamente, os governos das maiores potências e nações da Terra!!!
      E enquanto o dinheiro desperdiçado em armamentos (que não beneficia ninguém exceto um punhadinho de megacorporações) só estimula o ódio fratricida, separatista e a beligerância entre os povos humanos, e aumenta o risco de a humanidade se autodestruir, a busca de outros mundos habitáveis e, por tabela, de inteligência extraterrestre, extrassolar, é uma atividade que certamente terá um efeito unificador sobre os habitantes deste planeta, colocando em seu devido (e insignificante) lugar a mesquinhez de nossas picuinhas internacionais e intraterrestres em face de uma Galáxia de 300 bilhões de estrelas e planetas, muitos habitáveis, e quiçá habitados por civilizações mais antigas e mais sábias – ou tão novas e tão tolas – que a nossa. E, se contra toda a expectativa, for comprovado que o planeta Terra e sua humanidade são únicos e especiais nesta Galáxia, isso não aumentaria ainda mais a responsabilidade dos seres humanos, que deveriam pensar cem vezes antes de inconsequentemente suicidarem-se em tolas disputas tribais com o uso de ICBMs e outras porcarias bélicas?

  2. Wayne Hawk


    You and I would be in complete agreement on this one if it were only “a few bucks” that was invested.

    Hey, I was just as shocked as anyone that I didn’t agree with this because it is and has been one of the greatest mysteries “out there”. If these planets do have some form of life on them, they are all (so far) so unattainable now and in the near to far future (if ever) that to go a next huge step and see if they are intelligent or gaining any knowledge from or of them would and will take forever let alone traveling there…the current cash could be put to better use in another part of the “space program” (public and private sectors) so we could benefit from knowledge our own solar system will give us NOW. We are only scratching the surface of what our own solar system is and how all the planets/moons work. We know more about our oceans and what and how that works than we do of our own solar system! We know surprisingly little about the oceans of our own planet, in case you didn’t know. ;-}

    Like I said, this is the ONLY one and is simply my opinion. I can totally see where you and those that agree with your opinion are “coming from” though. So to me, this isn’t really a huge deal but I felt I had to see what others though about this. That’s all.

    Aloha For Now!

    1. astrobob

      Hi Wayne,
      I do understand your point of view. Money is always a limiting factor. If you were to make an argument we should invest more in learning about the ocean’s inhabitants, I’d be hard pressed to disagree.

  3. Giorgio Rizzarelli

    Great news Bob.
    What’s also great, is that (according to the Wikipedia article about the star) this appears to be a red dwarf which ended its period of dramatic flare activity. I noticed also that it has a low metallicity, though the several possible rocky planets. Possibly the two facts aren’t a coincidence: it may be a star developed a long time ago (when less metal had formed from stars), so having had all the time to end its turbulent activity phase (and we know red dwaves may have long life). What do you think?

    1. astrobob

      Hi Giorgio,
      I read the reference article cited in Wikipedia and see that the star’s age is given as greater than 2 billion years (AB components are between 2 and 10 billion, the sun’s age is about 5 billion). I’m not sure how metallicity is related to flare activity, but the star does appear to be old enough to have settled down. The planets were probably scorched by earlier flares; now that the star has quieted down, the evolution of life might be a possibility.

  4. d.rex

    This is one of the most amazing discoveries I have seen. I can’t believe the things being found in the universe and I’m so glad this is happening in my lifetime. Everything we thought we knew is being turned upside down. We can’t be sure what is in this system until we go there — and whatever is being postulated is most likely wrong. Three (!) planets clustered together so tightly and in such proximity to the parent star — this would have been thought impossible only a very short time ago. Could this phenomenon be evidence of planetscaping by an alien race?

  5. Deng Emmanuel Jokgaak

    Wow! This is great “News”, great news I ever heard since I start reading about space discoveries many years ago. However, this is of no surprise to me because I believe there must be other planets around this vast universe whether close or far from us. Since I start reading on line, it is a matter of time and we will be somewhere – somewhere that support life whatsoever times it may take, we will one day make it there. The only problem is that our scientists may be lacking equipments – sophisticated ones capable of supporting our earthly ideas and carry us all the way, I do n’t know how many light years to a dreamed land or heaven. It sounds a joke but it will be some day. My fear is that if scientists drawing back due to lack of fund and the whole dream die just like that.

    1. astrobob

      Thanks for your thoughts on the matter. Let your legislators know that we need to to support astronomy research and space science. The more people who do, the better chance there will be money for these projects now and in the future.

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