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2nd Planet Hunters Paper Submitted

Way back in January I blogged about our announcement of two new candidates, confidently predicting that the paper would be out in the next few days. That didn’t happen for all sorts of reasons, but it’s now submitted to the Astronomical Journal. Rather than wait until we get the referee’s seal of approval (or a lot of criticism!), we’ve made the paper public via the arXiv – you can read it here.

Congratulations to Robert Gagliano, Joe Gilardi, Kian Jek, Jari-Pekka Paakkonen & Tjapko Smits

As the picture on the blog post shows, five volunteers are co-authors, many more are thanked in the paper, and there’s a link to the authors page to give credit to all our volunteers for taking part. In the month or so that we’ve had since the conference, we’ve done some more work to pin down the behaviour of these systems. The first exciting new discovery was the length of time between transits was changing slightly for KIC4552729. These transit timing variations, or TTVs, suggest that there’s something else there, another body whose gravity is affecting the orbit of the planet candidate whose transits we do detect. We need more data to work out exactly what’s going on, but the immediate implication is that it’s more likely that our planet candidate is real, as it’s harder to create a three-body system using interference from background eclipsing binaries.

We also – mostly for fun – worked out whether the two planets that Planet Hunters had uncovered could be in the habitable zone of their star, that thin sliver of space where liquid water, and hence life, might be able to survive on the surface of a planet. Now, both of ours are almost certainly too large to be anything but gaseous, and one has to make a planet’s worth of assumptions about things like its albedo (how much light is reflected and how much absorbed by the atmosphere) and its atmosphere. Nonetheless, the encouraging thing is that both of our candidates seem to lie in the habitable zone of their star system, making them interesting targets.

As if that wasn’t enough for one day, also on the arXiv and submitted to the journal is the latest Kepler paper announcing new candidates. They include a section on Planet Hunters, and announce another handful of independent discoveries where we found candidates they’d already uncovered. More on that – including a list of Planet Hunters involved in those discoveries – in the next few days.

Two new discoveries announced at AAS

We’re delighted to announce that you’ve done it again, with two new planet hunters discoveries being announced at the 219th meeting of the American Astronomical Society meeting in Austin, Texas today. Both of these were missed by standard procedures and have only been found because of the efforts of volunteers.

Both of these were sequences of transits that were picked up by planet hunters volunteers, both using the main site and via Talk, and we’ve done enough work that we’re confident that they’re real. They thus become the third and fourth planet candidates to be discovered by Planet Hunters. Congratulations to those involved both on Talk and in the interface.

Discovery of a transit around KIC10005758

Preliminary work indicates that the first, around the star KIC 4552729, has a 97.5 day period and is approximately 4 times the radius of the Earth. Its transit was caught amongst Quarter 2 data, and we’ve confirmed that it repeats in later data. We can’t quite call this a planet yet, but with more than 95% certainty in our discovery it becomes an official planet candidate.

The second candidate is even more exciting. It orbits around the star KIC 10005758, has a 284 day period and is just 3.3 times the size of the Earth. The first transit was caught in Quarter 2, and analysis by the Kepler team caught another, larger planet, closer to its star and orbiting it every 132 days. Not only is it exciting to have the first Planet Hunters multiplanet system, but this makes it much more unlikely that we’re being fooled by a background eclipsing binary.

I’ll post more after my talk, and we hope to have a paper finished and uploaded in the next couple of days. In the meantime, congratulations to our roll of honour :

Lubomir Stiak, Kian Jek, Robert Gagliano, Pamela Fitch, Dr Johann Sejpka, Jari Paakkonen, Gregoire P.A. Boscher, Matthew Lysne, Thanos Koukoulis, Andre Engels, Ben Myers, Daniel Posner, Terrence Goodwin, Theron Warlick, Charles Bell, ‘damalimaan’, Sean Parkinson, Samuel Randall, Eduardo Mariño, Frank Barnet, Terrence Goodwin, Ewa Tyc-Karpinska, Heinz W. Edelmann, Lynn van Rooijen-McCullough, Gary Duffy, ‘kamil’, Branislav Marz, ‘Adnyre’ and Colin Pennycuick.

If you’d like to join them as discoverers of planet candidates, then keep clicking at Planet Hunters – there must be more in there to find, and we have new data coming shortly to keep you all busy!

Chris & the Planet Hunters team.

PS I’m struck in looking through that list of names as to how international the Planet Hunters community is. I’d like to thank Lech Mankiewicz and his team who led the charge to make Planet Hunters available in other languages.

A Good Start to 2012

Happy New Year and Happy 2012 Everyone –

We’ve got lots in store for 2012. I wanted to give you a quick update on what the team’s been up to. We’re still notifying winners of the Anniversary Competition and  waiting to hear back from some of the winners. So we’ll announce the remaining winners soon. We hope to start mailing prizes in a couple of weeks once I’m back from travel and conferences.

January is turning out to be a busy month.We’ve got papers in the works, including my short period planet analysis paper from all your classifications from Q1. I hope to have a finished draft in the next few weeks. Watch this space to hear more about the papers in the upcoming weeks as we ready them for journal submission.

Next week is the American Astronomical Society‘s annual winter meeting. This year the meeting will be held in Austin, Texas. Chris, Kevin, and I will be attending the meeting with mugs of garcinia cambogia coffee in hand. If you’re interested in following the news from the conference on twitter – you can follow Chris, Kevin, and I (@chrislintott , @kevinschawinski ,and @megschwamb ) and the twitter hashtag #AAS219 . We’ll also be tweeting from the @planethunters account as well.

Chris will be talking about the latest Planet Hunters results on Monday in the  Exoplanets: New Surveys session. The talks are short, only 5 minutes to speak and show slides with a few minutes for questions. So we’ll be showing just the latest science highlights from the project. Kevin and I will also be giving talks on other unrelated projects we’ve been working on. I’ll be talking about my  survey to search the southern skies for large Kuiper belt objects, but I’ll also be giving a talk on Planet Hunters next week but not at the AAS. The annual symposium for the National Science Foundation (NSF) Astronomy and Astrophysics Postdoctoral Fellows is right before the AAS meeting in Austin. My symposium talk on Sunday will be about Planet Hunters.

Also up next, is the next data release. With the accelerated data release schedule from the Kepler team, we’re going to get not just one quarter but 3! Quarters 4,5,and 6 are scheduled right now to be released this weekend. That’s about 1.25 years worth of Kepler data (Quarters 1-6)  in total will be in the public archive. I’m excited to see what unknown planets may be lurking there just waiting to be found. We’ll keep you updated on the process of the upload and when the data will be available on the site.

A good start to 2012 indeed,



This world cloud shows the first Planet Hunters paperoutlining the discovery of two planet candidates – as a ball of words. You might call it a Word Planet, in fact. The words used most often in the paper are the largest, such as transit (81 times), planet (71) and Kepler (51), whereas less-used words shrink away to the edges, such as SNR (5), technology (2) and faint (3).

This was created for the 2011 Zooniverse Advent Calendar. Download the full-resolution version here.

How to Navigate the Astro Literature, Part 1

This is a cross post from the Galaxy Zoo blog – since it’s about the astro literature, it applies directly to exo-planet research.

So you want to learn about current astrophysics research? You’re in luck! Not only are there many excellent blogs, pretty much all of the peer reviewed literature is out there accessible for free. In many areas of science, the actual papers are behind paywalls and very expensive to access. Astrophysics, like a few other areas of physics and mathematics, puts most papers on the preprint server where they are all available for download form anywhere. In addition, we have a very powerful search tool in the form of the NASA Astrophysics Data System which allows you to perform complex searches and queries across the literature.

Suppose you wanted to learn more about the green peas, one of our citizen science-led discoveries. Your first stop could be the ADS:

ADS, like any search engine, will now scour the literature for papers with the words “green peas”, “green” and “peas” in it, and return the results:

As you can see, the discovery paper of the peas, “Cardamone et al. (2009)” is not the first hit. That’s because in the meantime there has been another paper with “green peas” in the title. You can click on Cardamone et al. and find out more about the paper:

This is just the top of the page but it already contains a ton of information. Most importantly, the page has a link to the arxiv (or astro-ph) e-print (highlighted). Clicking there will get you to the arxiv page of the paper where you can get the full paper PDF.

Also there is a list of paper which are referencing Cardamone et all, at the moment 23 papers do so. By clicking on this link you can get a list of these papers. Similarly, just below, you can get a list of paper that Cardamone et al. is referencing.

Lower still are links to NED and SIMBAD, two databases of astronomy data. The numbers in the brackets indicate that SIMBAD knows 90 objects mentioned in the paper, and NED knows 88. By clicking on them, you can go find out what those databases know about the objects in Cardamone et al. (i.e. the peas).

Obviously there’s a lot more, but just with the arxiv and NASA ADS you can search and scour the astrophysics literature with pretty much no limits. Happy researching!

A word from planet hunter Geoff Marcy

Dear Planet Hunters,

The Planet Hunters project has found a gold mine!   I am so impressed at the planet candidates rolling out of Planet Hunters.  This project shows the human ability at pattern recognition can compete with modern, parallel-processing computers.  The human eyeball (and brain) can still give a massive computer a run for its money.

How can PH humans compete head-to-head against NASA computers?   I really don’t know.   I imagine that the subtle, unpredictable quirks and complexities in the photometry of 156,000 stars presents challenges native to our ancient brains.   Perhaps our hominid ancestors, so vulnerable to predators, had to survey the African savannah quickly and accurately, to detect the barely discernible signs of trouble.   Every sunset two million years ago, our ancestors would routinely venture out to forage.  If you missed a distant saber tooth silhouetted as it transited the setting sun, you might become that evening’s appetizer.   If so, Planet Hunters is reaching back to our roots, to our native strengths.  And in so doing, future destinations in humanity’s exploration of the cosmic savannah are being discovered.

Congratulations, Best Wishes, and Keep going!
Geoff Marcy

A word from Bill Borucki: Kepler P.I.

Dear Planet Hunters:

I’m writing to congratulate you on your wonderful discovery of some unique new planet candidates.  I began designing and working on the idea of a space-based transit mission in the early 1980’s so that we could determine whether Earths were frequent or rare in our galaxy.  The project encountered many obstacles, but the Kepler team overcame each of them and celebrated the Mission launch in March 2009!  It is exciting to see the bounty of planets that Kepler has discovered and it is especially gratifying that all of you have been willing to contribute so many hours of your time to help us discover new planets.  I understand that collectively, your contribution amounts to more than 50 years of “human processing time.”   We now stand at the threshold of detecting planets in wider orbits; planets that might be habitable worlds or might have moons that are habitable.  Transits around these more distant planets will be different than many of the transiting planets that you’ve discovered so far – these planets will have transits that are longer in duration than the transits of close-in planets, but they will be more difficult to find because they will occur less frequently.  I hope that you will redouble your efforts to find these rare but important long period planets.  Good hunting. The Kepler team really appreciates your help!

Bill Borucki, Science Principal Investigator for the Kepler Mission

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.