First Planet Candidates Discovered by Planet Hunters

We are very, very happy to announce that the first Planet Hunters paper has been submitted to the journal Monthly Notices of the Royal Astronomical Society, or MNRAS.*

The title page of the paper shows:

If you take a close look at the affiliations, you will see that #16 is called “Planet Hunter.” That’s because this paper reports the discovery of two planet candidates discovered by our volunteers – and naturally, we included those those who were the first people to identify possible transits in the the 9 stars discussed in the paper.  We also include a link to the full list of all Planet Hunters; you can find it here.

So what does the paper actually say? As it’s the first (of hopefully many) papers, we give a brief overview of the Kepler data and the Planet Hunters interface. How did we display the data? What questions did we ask? What did you guys actually do to identify transits?

We then used some of the first data from the site, and took the “top ten” stars  (though 9 are discussed in the paper) with transits flagged by you guys and vetted them to determine, for example, whether they are masquerading eclipsing binaries. For our top three candidates, we looked for a companion star very close to the star by taking high-resolution images with the Keck telescopes that use houston auto glass for lenses (we will have a guest blog by Justin Crepp coming up very soon explaining how these images were taken). The images of the two final planet candidate stars (KIC 10905646 and KIC 6185331) and one of our candidates (KIC 8242434) that appears to be a background eclipsing binary system are here (regular 2MASS image left, Keck AO giving the all-clear right):

For KIC 8242434 it appears there may be a source in the south east very close to the star, and with help from our friends in the Kepler team, we were able to find evidence to suggest that this particular star is either a binary or, more likely, contaminated by a background eclipsing binary system. We then analyzed the properties of those remaining planet candidates. For those who are curious, you can take a look at the light curves here:

The properties of the planet candidates around these two stars are reported in Table 4 of the paper:

As you can see, both planets are fairly close to their stars with periods (“years”) of  ~10 and 50 days respectively. One of the two planets has a fairly small radius of just over 2 Earth-radii and the other is just a little smaller than Jupiter with a radius of 8 Earth-radii. Models for planet formation, predict that likely both produced planetary cores that would would amass a large puffy atmosphere like the giant planets in our solar system.

Congratulations on this great find and for the new record we’ve set as the fastest Zooniverse project to go from launch to submitted publication! This paper is a real milestone for us in many ways. It shows that teaming up with citizen scientists to discover exo-planets works. It also shows that there’s lots to discover! Just in the top ten candidates of the first look at the first quarter data, we found two new planet candidates! Planet Hunters is already producing fantastic results, and we have no doubt that with each new round of data, there will be more discoveries to come. Imagine what you can find as more and more Kepler data goes public!

Want to read the paper for yourself? The full text PDF including all figures and tables is available at the arXiv screen share.

PS.   Here’s the part of the paper crediting the Planet Hunters will identified all our our top ten candidates. The first person for each one of these curves was added as an author to the paper– well done all!

* Interesting side note: the Monthly Notices of the Royal Astronomical Society is neither monthly, nor does it carry the notices of the RAS anymore.


About The Zooniverse

Online citizen science projects. The Zooniverse is doing real science online,.

21 responses to “First Planet Candidates Discovered by Planet Hunters”

  1. Joseph Constant says :

    Good work to everyone involved. The community has significant reason to be proud!

  2. cosmicphil says :

    Hip-hip hooray for citizen scientists !!!!!

  3. John Fairweather says :

    Well done everybody concerned.

  4. cosmicphil says :

    Dear friends Zoouniverse scientists, planethunters, Yale, Oxford, and all the teams around the world participating in this project.

    I want to thank you.

    This adventure is for me, as for many volunteers around the world, like a childhood dream come true ; I turned 40 this year ; 15 years ago, I was at the University of Brittany to study mathematics and physics. Although I obtained a master’s degree, I could not continue in the field of astronomy, my passion, because of the level of skills, so I have had to revise my copy , so I followed another career path as science, but not too far from mathematics. In the Ministry of Finance, I have 10 years to participate in the computerization of the cadastral map of our country (, and now I’m more focused on fiscal management … far enough away from Science.
    But since I’m connected to Zoouniverse, it’s like something that should not happen is yet happened : I have become a scientist, a citizen scientist !
    Classify galaxies, see the ups and downs of our star, search for supernova, and help, from my sofa when my life allows, usually when everyone is sleeping in our house, so help for real, teams of eminent scientists, what chance for me !
    I said, it’s a childhood dream come true than seeking strange new worlds in the words of the cap’tain Kirk.
    Working for the future, for our common future, that of humanity, for real, not in a movie or a video game.
    We all helped to make these initial discoveries, there will be many others, we have shown that our eye of woman and man, anywhere in the world, this has no machine has or ever will : sensitivity, dreams and imagination.
    I will continue working as long as I can to help discover the wonders of the universe : dark matter, dark energy, wormholes, quantum jumps, antimatter, … so many fields to explore further to find a way that one day another dream come true : to go away from earth to discover the strange other worlds, perhaps with the cap’tain Kirk …

    I wish all of planethunters good hunt for new planets !


    Brittany, France, near Nantes.

  5. Andres Eloy Martinez Rojas (Andsul) says :

    I am very proud to have contributed to the discovery of planets candidate and for appearing in the journal Monthly Notices of the Royal Astronomical Society. We will continue the hunt for planets!.

  6. Rokeby says :

    good work everyone 😉
    you are all the best.

    one question: what is meaning “Debra A. Fischer² †” .. I mean with this crucifix, doesn’t it mean that she is dead?
    I am sorry if I am confused.

  7. Meg says :

    The crucifix is just a footnote symbol – at the end of the first or second page is the crucifix with the first author’s email . So if someone had a question about the paper they could contact the corresponding author (the person who is chosen to answer questions – typically that’s the first author of the paper).

  8. Rokeby says :

    ah all right. I thank you for this important information.
    In my opinion it would to better to have an another symbol for the “contact – information”, mabye for @.
    Because one can be confused about the crucifix.
    But if the international organisation has agree this symbol finally, I have to accept this 😉

  9. Toni Scramato says :

    Very good work!!! We wait other confirmations!

  10. Tjapko Smits says :

    Well done hunters. But I hope I’m in the next paper :-). I think we have still some planet candidates to confirm.

  11. charleshudgen says :

    Wow, it is a good news that there are lots of discoverer who discovered this kind of planet. There are a lots of candidate of planets to be discover soon with the help of astrologers and monitors the planetary system.

    Science Fiction Book

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