The Kepler Mission

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EarthlingX

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Kepler Mission Manager Update
http://www.nasa.gov/mission_pages/kepler/":24omdhm3 said:
Feb. 8, 2010
Kepler experienced a safe mode event on February 2, 2010. A safe mode is a self-protective measure that the spacecraft takes when something unexpected occurs. During safe mode, the spacecraft points the solar panels directly at the sun and begins to slowly rotate about a sun-aligned axis. As a safety precaution, the spacecraft turned off a redundant system, photometer, and both star trackers.
The scientific data, collected since the last download of science data in January, was not in danger and was downloaded successfully via the NASA Deep Space Network during recovery operations. Engineers verified that all of Kepler's systems were functioning correctly and successfully recovered the vehicle from safe mode. The spacecraft resumed collecting scientific data on Feb. 5, 2010.
 
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Astro_Robert

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I was under the impression that Kepler would release data approximately quarterly. It has been 3 months since the last release (Jan 4 + 3 months ~ April 4). Does anyone have any idea if more releases are forthcoming?
 
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MeteorWayne

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IIRC, the first major release was scheduled to be a year after science operations started.

"Mission Manager Update April 5, 2010

The Kepler project team successfully completed another science data download March 19-21, 2010. This download of data included science data collected since Feb. 5, 2010, following the Safe mode recovery that occurred in early February.

Kepler project engineers also completed a quarterly roll of the spacecraft during this contact. The roll of the spacecraft -- done once every three months -- keeps the spacecraft's solar arrays properly aligned toward the sun for optimal power generation. During the contact with the spacecraft, engineers also uploaded updated new target tables for Kepler's next observing quarter. The data downloaded during the contact is being processed through the Science Operations Center at NASA's Ames Research Center.

Meanwhile, Kepler project engineers are preparing for the next science data download, scheduled for April 21-23, 2010. The next monthly data download contact will be unique. This satellite commanding session will include an update to flight segment software, the first update for Kepler's onboard flight software since its launch on March 6, 2009. This upload will provide an update to star tracker and flight software interactions to help mitigate errors that might lead Safe mode events. The flight software update has been in development and test for a number of weeks, and is ready for flight operations.


http://kepler.nasa.gov/Mission/discoveries/
 
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Astro_Robert

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I am still waiting for Kepler to release more data, but in the meantime I checked their Blog and it seems they had a dissapointment (CCD module) in late Feb. Here is an excerpt from the Feb-18 Blog:


On the plus side, the changes we made back in September seem to be working great and our pointing accuracy has been superb, with no more incidents of the unexpected drops into our coarse-point mode. I did tell you about that, didn't I? We're continuing to make minor tweaks in the spacecraft operation to improve performance or reduce risks, and looking forward to the day when we can't find any more improvements to make, all to make the data better with less noise.

In December, we changed some settings on a heater that was cycling on and off every few hours and was somehow showing up in the stellar brightness measurements (somehow it seems to be affecting focus very slightly). Hours is about the duration of a planetary transit, so we really don't want things changing on that time scale. On the other hand, the heater is cycling to keep the reaction wheels warm, and we count on these wheels to keep us pointed accurately. So what we did is narrow the temperature limits, and now the heater cycles every 12 minutes or so, and isn't such a bother.

We are also getting ready to make some changes to the software running on the spacecraft. Updating the software requires us to reboot the processor, something you don't want to do very often, because there's always the chance it won't come back on! But we've been saving up a few minor bug fixes, and now have a more important bug to fix. It sent us into Safemode in November, and as long as we're going to fix that one, we're going to do the others, too. But we'll do a lot of testing first, and we'll make the update in April, during one of our regularly scheduled data downloads.

Otherwise, things are going rather well, so I don't have a lot to write about. Not that that seems to have inhibited me much.

Actually, there was a new development in January that had us hopping. In fact, it's delayed this update while we worked on it. It seems that one of our detector modules died.

Hopefully it's only dead, not dead dead, and maybe we can revive it. But it doesn't look good. This is the most serious issue we've had since we started gathering science data.

One of our modules (Module 3, on the edge of our field of view) stopped working on January 9. Since then it's been dark, with no star images.

The Kepler focal plane is approximately one foot square. It's composed of 25 individually mounted modules. The 4 corner modules are used for fine guiding and the other 21 modules are used for science observing. Attached are some pictures that show a single science module and the assembled focal plane with all 25 modules installed. Note that the fine guidance modules in the corners of the focal plane are very much smaller CCDs than the science modules.

Under normal operations, each module and its electronics convert light into digital numbers. For the darkest parts of the image between stars, we expect these numbers to be very small (but not zero). Correspondingly, for the brightest stars in the image, much larger numbers are expected creating an image of each observed star and its background neighborhood. The numbers we see coming out of failed module 3 are all very similar in size and considerably lower than the normal levels. These numbers produce an image that looks like the "snow" on a television that has very bad reception. There are no stars visible in these images.

There are several ways a module to go bad, such as a blown fuse, a shorted or broken wire, or the failure of individual parts. The Kepler detectors were fabricated to rigid standards and subjected to rigorous testing on the ground before launch. And the design contains several redundant features to prevent the failure of a module, but the space environment is unforgiving and failures do occur. The fact that this anomaly affects all four channels on one module will help determine the probable cause.

Depending upon what caused the module to stop working, we might be able to recover it, though the flexibility of the Kepler design is limited in this extent. Even if the module is recoverable, it will be several weeks before recovery actions are taken because we need to review the current performance and design to ensure that any recovery steps do no further damage to the focal plane or spacecraft. I mean, the last thing we want to do is lose more modules while we try to recover this one!

The module that has stopped working is on the periphery of the field of view. Since the Kepler spacecraft rotates by 90 degrees every three months, this module would normally observe a different portion of the Kepler field of view each season, as shown in the following image. Hence, no part of the Kepler field of view has been rendered unobservable it's just that four regions are only observable three out of four seasons, or 75% of the time, if the module is unrecoverable.
 
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Astro_Robert

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From the Manager Update thread on the mission site:

05-03-2010
Data download and ground-based follow-up observations in full swing
Kepler engineers used three ground-stations in NASA’s deep space network, at Madrid, Spain, Canberra Australia, and California, for this month's data download. The Guest Observer Program has evaluated proposals to the Kepler cycle 2. The Science Team continues to analyze data on over 200 planet candidates. With Cygnus now visible, ground-based follow-up observations of Kepler’s candidate targets is underway at the Fred Lawrence Whipple Observatory in Arizona, McDonald Observatory in Texas, and the Keck 10-meter telescope at Mauna Kea, Hawaii.

Wow huh, 200 planet candidates awaiting verification. That must make the mission folks thrilled.


Anyway, brief recap on mission expectations:
Summary of The Expected Results
Based on these assumptions and the capability of the Kepler Mission, we expect to to perform a census of planets with periods from days to a few years and to detect:
Terrestrial inner-orbit planets based on their transits:
• About 50 planets if most have R ~ 1.0 Re (Re = Radius Earth for laypeople)
• About 185 planets if most have R ~ 1.3 Re
• About 640 planets if most have R ~ 2.2 Re
(Or possibly some combination of the above)
• About 12% of the cases with two or more planets per system
Giant inner planets based on the modulation of their reflected light:• About 870 planets with periods less than one week
Giant planets based on their transits:• About 135 inner-orbit planets along with albedos for 100 of these planets
• Densities for 35 of the inner-orbit planets, and
• About 30 outer-orbit planets.

Systems are expected with two or more terrestrial planets seen in transit in or near the HZ. More than one planet per system can be detected when a planetary system with small relative orbital inclinations is viewed near either node of the intersection of the orbital planes. The chance of seeing a second planet is 12% when one planet has already been found (Koch and Borucki, 1994) for systems having similar spacing and inclinations as the Venus-Earth analog.
If binary stars do not have planets, then the number of systems expected is about 46% less.
In summary, the Kepler Mission produces a statistically valid sample, sufficient to establish the frequency and distribution of planets in both single and multiple stellar systems as stated in the Goals. The expected results are rich enough that substantially different results still greatly enhance the communities understanding of extrasolar planetary systems.

Note that the mission probably only askes for follow up observations after 3+ transits demonstrating a firm period. Thus most of the detections, especially now only 1 year into the mission will be inner planets. Planets on Earth like or farther out orbits, may have had one transit but probably are not on the follow up list. Also, the reason the number of outer orbit planets is so low is that the mission only lasts 4 years, so the probability of Saturn class planet in a similar orbit having a transit during such a window is low.


Also, on the site Blog, it was also mentioned that the Kepler site won a ‘Webby’ award. There was also a brief description of exactly what a webby is.
 
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MeteorWayne

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It takes at least 3 transits, so 3 years for planets with a 1 year orbit like ours.
 
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Astro_Robert

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Coming soon ... Public release of 43 days of science data:

I got this from the Mission Manager's Blog


Anniversary of on-orbit operations and upcoming public data release
06.04.2010
May was a busy month for the Kepler Mission. On May 12, 2010, the Kepler project team marked the one-year anniversary of on-orbit operations. As we commemorated the date, the team was in the final stages in its preparations to release Kepler’s first 43 days of science data to the public. Scheduled for June 15, 2010, the data will include observations from more than 150,000 stars (more information below). Meanwhile, the project successfully completed another monthly science data download on May 20, 2010. This data volume was about 95 gigabytes, and represented Kepler’s Quarter 5, Month 2 collection. As the download was completed, the team was already making preparations for the upcoming June science data download, scheduled for June 22-25, 2010. This science data download will also be made in conjunction with another quarterly roll of the Kepler spacecraft. The roll will place Kepler in its summer attitude for three months. This allows for Kepler’s solar arrays to be optimally aligned toward the sun for spacecraft power generation.

The science team has worked very hard this last month preparing for the upcoming release of data to the public. On June 15, 2010, the first 43 days of data will become publicly available at the Multi-Mission Archive at STScI (MAST: http://archive.stsci.edu). The team worked around the clock to identify as many transit-like events in those data as possible. Consequently, the number of planet candidates has more than doubled in the last month. And as we search for planet candidates, we inevitably find eclipsing binary stars. In fact we found many thousands of these eclipsing binaries! We've catalogued nearly three thousand such systems. Both the binary catalog and a list of a few hundred planet candidates will be published this month to coincide with the data release. It's our hope that the public and the astronomical community will join us in the analysis of Kepler's incredible data and in the painstaking and methodical process of sorting out which candidates are, indeed, new worlds.

To present a comprehensive overview of these results to the public, four papers are being written. The first discusses the characteristics of planetary candidates in the released data with respect to the distributions of size, semi-major axis, and orbital period. The location and magnitude of the stars they orbit also are provided, so that they can be analyzed by other observers. To avoid wasting valuable telescope time, a second paper identifies and discusses the candidates in the released data that are believed to be "false alarms." These are events in the released data that are caused by astrophysical phenomena that mimic the transit pattern expected for exoplanets. Over 2,000 eclipsing binary stars have also been found and their identity and characteristics are discussed in a third paper. The fourth paper discusses the discovery of several stars that show the presence of two or more candidates transiting the same star. If these candidates prove to be planetary systems, they will be the first transiting multi-planet systems ever discovered.
 
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EarthlingX

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http://www.nytimes.com : In the Hunt for Planets, Who Owns the Data?
By DENNIS OVERBYE

Published: June 14, 2010

We are about to find out just how generous nature really is.



On Tuesday, astronomers operating NASA’s Kepler spacecraft will release a list of about 350 stars newly suspected of harboring planets, including five systems with multiple candidate planets. That data could dramatically swell the inventory of alien worlds, which now stands at 461, none of them habitable by the likes of us.

Astronomers everywhere, who have been waiting since Kepler’s launch in March 2009 to get their hands on this data, will be rushing to telescopes to examine these stars in the hopes of advancing the grand quest of finding Earthlike planets capable of harboring life out there.

But a lot of attention has been paid in astronomical circles over the past few months to what the Kepler team will not be saying. By agreement with NASA, the team is holding back data on its 400 brightest and best planet candidates, which the astronomers intend to observe themselves over a busy summer.
Wenderro":pe1yegla said:
http://arxiv.org/abs/1006.2799 - Characteristics of Kepler Planetary Candidates Based on the First Data Set
arxiv.org/abs/1006.2799":pe1yegla said:
Abstract
In the spring of 2009 the Kepler Mission conducted high precision photometry on nearly 156,000 stars to detect the frequency and characteristics of small exoplanets. On 15 June 2010 the Kepler Mission released data on all but 400 of the ~156,000 planetary target stars to the public. At the time of this publication, 706 targets from this first data set have viable exoplanet candidates with sizes as small as that of the Earth to larger than that of Jupiter. Here we give the identity and characteristics of 306 of the 706 targets. The released targets include 5 candidate multi-planet systems. Data for the remaining 400 targets with planetary candidates will be released in February 2011. The Kepler results based on the candidates in the released list imply that most candidate planets have radii less than half that of Jupiter.
Khm .. :shock:

Wenderro":pe1yegla said:
http://arxiv.org/abs/1006.2763 - Five Kepler target stars that show multiple transiting exoplanet candidates

http://arxiv.org/abs/1006.2815 - Kepler Eclipsing Binary Stars.
 
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DarkSands

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This is from the report posted above:

The Kepler results imply that;
1) Most candidate planets are significantly smaller than Jupiter.
2) There is a broad maximum in the frequency of candidates with orbital period in the range
from 2 to 5 days. This peak is more prominent for large candidate planets than it is for small
candidates.
3) The measured occurrence frequencies of Super-Earth-, Neptune-, Jupiter-, and Super-
Jupiter-size candidates in short period orbits are 2.5x10-3, 1x10-3, 0.9x10-3, and 2.x10-4, respectively.
4) The distributions of orbital period and magnitude of the candidates larger than Jupiter
appear to be quite different from those of smaller candidates and might represent small stellar
companions or errors in the size estimation of the dimmest stars in the Kepler planet search
program..
Pretty interesting stuff, if these findings are correct earth sized planets maybe much more common than Jupiter sized planets.
 
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AdmiralRitt

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I think planetary formations models are going to be over turned by the Kepler results.

Some Eye openers, And the possibility of lots of undesirable real estate.

Were we really expecting so many planets so close to their primaries. ?
I was hoping that the planets already discovered by gravity/doppler measurement were
a severe bias that was in no way indicative of a general rule.
The latest dispatch from the Kepler team hopefully states
"many bodies substantially smaller than jupiter",
Well, neptune is substantially smaller than jupiter but it still masses
17 earths?

What kind of habitability can we expect from a super earth.? say an earth analogue with Radius 50% larger
gravity. easily 2 times the gravity for a iron core world. Atmospheric density 3 Atms. If there is fauna creating
oxygen there you can bet it's not more than 7-8% of the total atmosphere, as corrective burning would create
a balance. That big Core would cool off much slower than the earth's. Their Hadean-geologic period may last
more than half of span of their primary if were talking F type or hotter stars.

It would be a tragic comedy if the ordinaryness of the solar system turned out to be an incorrect assumption
 
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nimbus

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Well, there's still moons that could provide human-ish habitable conditions. It wouldn't really break the Earth's ordinariness if its only outlier characteristic was 1G gravity.
 
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alpha_centauri

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AdmiralRitt":295ci30a said:
Were we really expecting so many planets so close to their primaries. ?
I was hoping that the planets already discovered by gravity/doppler measurement were a severe bias that was in no way indicative of a general rule.
You do realise that this is (some of) the data from only the first 43 days of science? As such it is only looking at planets with short orbital periods because planets further away from their star will take longer to complete their orbits and be seen to transit enough times to be considered as candidates.

Even then not every planet can be exactly like earth, same mass, and slap bang in the habitable zone. Out of the 8 planets in the Solar system only one is like that so I find it a tad unreasonable to demand that all exoplanets must be so. Indeed such a universe would be incredibly dull!

Anyway, the existence of planets very close to a primary does not preclude there being others in the same system and with more favourable attributes to being conducive to life.


AdmiralRitt":295ci30a said:
The latest dispatch from the Kepler team hopefully states
"many bodies substantially smaller than jupiter",
Well, neptune is substantially smaller than jupiter but it still masses
17 earths?
This is the data from the faintest stars observed and based on a relatively short period of data collection, it always was going to take some time to see lower radius planets, this is all merely a prelude. Even then many of the more interesting candidates from this 43 day period will have been the 400 or so held back. For example no one’s going to announce an earth-radius planet without having sufficient evidence considering the damage a false announcement could do to the integrity of the process.

What is clear from the data so far however is there is no reason to suggest previous models showing large numbers of low mass planets are incorrect.
 
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MeteorWayne

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AdmiralRitt":3k3w19up said:
I think planetary formations models are going to be over turned by the Kepler results.

Some Eye openers, And the possibility of lots of undesirable real estate.

Were we really expecting so many planets so close to their primaries. ?
I was hoping that the planets already discovered by gravity/doppler measurement were
a severe bias that was in no way indicative of a general rule.
Well, so far, this data suffers from the same bias. It's only been up for a year, so can only verify planets with orbits < 1/3 year (3 transits being required for confirmation). As time goes on (and is enhanced by ground based follow up obs) we will be confirming planets with longer orbital periods.
 
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EarthlingX

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SDC : Hundreds of Possible Alien Planets Discovered By NASA Spacecraft
By Denise Chow
SPACE.com Staff Writer
posted: 18 June 2010
04:54 pm ET



NASA's Kepler spacecraft hunting for Earth-like planets around other stars has found 706 candidates for potential alien worlds while gazing at more than 156,000 stars packed into a single patch of the sky.

If all 706 of these objects pass the stringent follow-up tests to determine if they are actually planets, and not false alarms, they could nearly triple the current number of known extrasolar planets. They were announced as part of a huge release of data from the mission's first 43 days by NASA's Kepler science team this week.
At least a couple of nice comments there.
 
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MeteorWayne

Guest
Excerpt reinforcinga point I've made before:

"And, since transits of planets within this habitable zone of solar-like stars occur about once a year and require three transits for verification, it is expected to take at least three years to locate and verify any potential Earth-size planet.

....

"We never thought we'd have this much this early, it's absolutely wonderful," Borucki told SPACE.com. "The instruments are working well, but we still have some work to do. We're certainly not finished with this kind of work, and each year, we go to more and more difficult targets. So, people have to be patient."
 
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EarthlingX

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I find this very interesting, from http://arxiv.org/abs/1006.2799 - Characteristics of Kepler Planetary Candidates Based on the First Data Set :


Figure 2. Number of Kepler candidates vs. planet radius compared with those in the Extrasolar Planet Encyclopedia (EE, updated 05/14/10). The results shown in the lower panel are from the EE and represent only those found by transit photometry.
It is clear from Figure 2 that the majority of the candidates discovered by Kepler are Neptunesize (i.e., 3.8 Re) and smaller while the planets in the EE are typically Jupiter-size (i.e., 11.2 Re) and larger. This difference is expected because of the difficulty of detecting small planets when observing through the Earth’s atmosphere.
The Kepler results shown in Figure 2 imply that small candidate planets with periods less than 30 days are much more common than large candidate planets with periods less than 30 days and that the ground-based discoveries are sampling the large-size tail of the size distribution (Gaudi, 2005).
Note that for a substantial range of planet sizes, a 1/R2 curve fits the Kepler data well.

Assuming the false positive rate and other biases discussed above are independent of planet size for planets larger than two Earth radii, this implies that the frequency of planets decreases with the area of the planet.
 
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3488

Guest
What will be fascinating IMO will be to get a distribution of types of stars ith planets, i.e how many hot A or F type stars (Sirius or Procyon types) as compared to sunlike G types or cooler K & M types also if possible sizes or even masses of these planets. Could Kepler detect a Jupiter sized world in orbit around an Arcturus or Aldebaran type red giant??

Of course there ill be entire solar systems that Kepler will not detect, those that are pole on, host stars like Vega or Tau Ceti, those we see pole on. However those like Regulus or Achernar, we see equatorwise on, we should get some great results from Kepler.

Looking forward to the results immensely.

Andrew Brown.
 
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3488

Guest
Re: Initial list of 300+ Kepler Planets

Thank you very much thnkrx. Fascinating. I've bookmarked it.

Further analysis will sift the ganuine ones from image noise, etc & perhaps extra ones will show up too.

Will be interesting to sift though them to get a kind of pattern, i.e how many orbit hotter A & F type stars, verses Sunlike G type stars or cooler K & M types.

Perhaps gas giants in orbit around ageing red giants like Arcturus & Aldebaran, verses those we are looking for, sort of Earth, Mars, Mercury sized planets in orbit around Main Sequence stars.

Andrew Brown.
 
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Astro_Robert

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I just had a silly thought:

1 of these Kepler planets might be named 'Bob', like the planet from the animated Titan AE movie.

Planet Bob, :lol:
 
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thnkrx

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Re: Initial list of 300+ Kepler Planets

Giving the list a looksee it seems like none of the candidate planets have an orbital period much over fifty days, with most checking in a well under half that. Lots and lots of 'big hot rocks'...but, this is with only a year or so of active observations.

Wonder if any of the other 400 odd candidate planets mentioned have longer orbital periods...and are more or less earth sized?
 
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mark_d_s

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Re: Initial list of 300+ Kepler Planets

thnkrx":2dmifbfe said:
Giving the list a looksee it seems like none of the candidate planets have an orbital period much over fifty days, with most checking in a well under half that. Lots and lots of 'big hot rocks'...but, this is with only a year or so of active observations.

Wonder if any of the other 400 odd candidate planets mentioned have longer orbital periods...and are more or less earth sized?
Here's the actual paper. It's very interesting.

http://arxiv.org/pdf/1006.2799v1
 
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