Archive by Author | The Zooniverse

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 arxiv.org 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!

PlanetHunters: the next steps

Hi Everyone!  The first two planets have been published, so where do we go from here? We reviewed several hundred light curves that you flagged and boiled these down to the revised list posted on the planet candidates page. The Kepler team has reviewed the light curves of all stars on that list –  several were identified as false positives, so we’ll be moving those stars off the planet candidates page.  However, about ten objects passed the first stage of validation and now Jason Rowe, Steve Bryson and Natalie Batalha on the Kepler team are looking at them more carefully and I’ll be traveling to NASA Ames soon, to meet with them about this work.

You also discovered several eclipsing binary systems and we are working with planethuner kianjin on this. One of our Yale undergrad students (Farris Gillman) is traveling to meet with Prof Andrej Prsa (at Villanova University) next week and model these EB’s.  We’ll post an update for you on progress from that work in the next week or two.

Another one of our undergrad students (Charlie Sharzer) is working on a senior thesis project, modeling the dynamics of moon captures by planets.  He is hoping to figure out which of the Kepler planets are a priori most likely to harbor moons.

The Kepler space craft is continuing to collect more data on stars in the field, however the Kepler field is fading from view of Earth-bound telescopes as we orbit the Sun – the stars will be visible again in April 2012 when we’ll be ready to follow up on additional  candidates that you find in the Q3 and Q4 data.

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

Updated Planet Candidates List and Q3 data

Hi all,

We’ve just updated the Candidates List to reflect what we’ve learned from Q1 and from a preliminary look through the Q2 data so far. Some candidates from Q1 have survived, others have not.  Each of these candidates looks promising to us and not on the  list of known  candidates released by the Kepler team.  These are possible planet candidates, that is, as far as we can tell, they look good and we think are not eclipsing binaries or false positives. But this doesn’t necessarily mean that these stars have planets. A minimum of three separate observed transits are needed as well as follow-up observations. From our first paper, you can see that after checking through everything only two of the top 10 we looked at turned out to be good. Many on the list might not turn out to be real planet transits,  but their appearance on our list means we think we’re on the right track. We will continue to follow-up and vet these candidates with observations from the Keck telescopes and other checks to try and rule out possible false positives.

We’re also keeping track of discovery credit. The names of those lucky hunters who are in line to make discoveries are listed on the candidates page as well. We have a full record in our database of what everyone did. Additionally, some of our candidates came from light curves that were highlighted in Talk, and we will be giving credit to those users who helped alert our attention to those light curves (we plan to have their names added soon on the Candidates List).

In other news, the Kepler team announced that the next public release of data has been moved up from June 2012 to yesterday . Quarter 3 is an extra 90 days of observations, nearly doubling the time baseline we have available for all the Kepler stars – meaning you can find even longer period planets hidden in the data! With the addition of Q3, we now have 210 days worth of Kepler data for ~150,000 stars. The team is hard at work making preparations for the new data, which included assembling the new candidates list. In the mean time, there’s still lots of Quarter 2 data left to search through, and the science team is continuing to search for transits in the Quarter 2 data with your classifications and Talk posts.

We are currently downloading the Q3 data, and Meg  is heading out to the folks at the  Adler Planetarium in Chicago early next week to help  check out the new data and  help plan the Q3 upload with our amazing Zooniverse developers who keep the Planet Hunters  site going. Our goal is to get the data served to you as quickly as possible with minimal interruptions to the site. We’ll keep you posted on the progress of the Q3 upload. So stay tuned!And thanks for all the clicks!

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.

A Citizen Science Win

With all the news coverage about “Tatooine” orbiting two stars, we were very excited to learn that in that most wretched hive of scum and villainy, the Planet Hunters Talk site, citizen scientist kianjin spotted Kepler-16! Kianjin even figured out that it must be a planet orbiting a double star.

“Tatooine” discovered by Kepler

Today’s breaking news is that the Kepler team have discovered a planet orbiting two suns, just like the fictional home planet of Luke Skywalker, Tatooine, in Star Wars.

Now we’re all Planet Hunters here, so everyone’s first question is, what does the light curve look like? Look no further, here it is: http://www.planethunters.org/sources/SPH10421275

The full article is online at Science Magazine (subscription required). You can check out the Kepler team’s website about the new planet here and here. Kepler-16, as it is now dubbed, is even more inhospitable than Tatooine – it’s a Saturn-mass gas planet. So unfortunately, no Javas or Cantina band….

News from Exteme Solar Systems II.

Hello Planet Hunters!  Grad student John Brewer is attending an exoplanet meeting this week in Jackson Hole, Wyoming, where there have been several exciting new announcements.  Of particular interest to planethunters.org, the Kepler team announced an astounding number of new planet candidates, and more than doubled the number of candidates in the habitable zone.  The list of 1235 planet candidates announced in February has grown to 1781 with 121 now in the habitable zone.  The number of earth-sized planet candidates increased by 95%!

The release date of the new candidate list is not yet set, but there is a bonus coming our way.  The Kepler team will be releasing the Q3 data on September 23, (six months early) and are moving up the Q4 release to January!  You will soon be swimming in new light curves.  One reason for the early release is the high demand for more data.  Congratulations, and thanks for all of your hard work.

John M. Brewer

The Science team just can’t resist a go

Its getting closer and closer to the day when the Kepler team will release the next few quarters of data. To get ready for it we are working hard behind the scenes to turn your clicks in to science and even more planet candidates. That doesn’t mean however that the science team isn’t lured by the hunt for planets. We all routinely go digging around in the light curves ourselves to help get that classification count up. Don’t believe us ? Want some proof? Well just take a look at this image of Meg intently looking for those elusive transits.

Meg classifying

Meg hard at work

Happy hunting