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Mission Manager Update

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While analysis of the Kepler mission data proceeds, we continue to operate the spacecraft for the K2 mission. In the Mission Manager update, I’ll provide periodic updates of the spacecraft operation, the team and the latest science results from the Kepler and K2 data. In this blog I’ll give you a view of the work we’re doing, and the various issues that we have to consider.Charlie Sobeck, Kepler and K2 mission manager

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

 

Mission Manager Update: Kepler’s K2 Mission Begins Campaign 13

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Last month the scientific community and the world were delighted with the announcement of a total of seven Earth-size planets orbiting a nearby star called TRAPPIST-1. Data from NASA’s Spitzer space telescope revealed the last four of these neighbors, and as planned, the Kepler space telescope also had an opportunity to look in on this interesting target.

During its observing campaign 12, covering the period of Dec. 15, 2016 to March 4, the Kepler spacecraft, operating as the K2 mission, monitored the brightness of TRAPPIST-1. Earlier this month, we released the raw, uncalibrated data to the scientific community, with the fully calibrated data to follow in the next few months. We are excited to see what these observations have added and will further contribute to the community’s investigation into the TRAPPIST-1 system.

Kepler’s K2 mission is now in its thirteenth observing campaign, monitoring a patch of sky in the direction of the constellation Taurus. During this campaign, the spacecraft will monitor more than 21,000 targets, including the Taurus star-forming region and the nearby Hyades open star cluster. Measurements of 33 galaxies, six asteroids, eight trans-Neptunian objects and one comet are also scheduled.

Observ

Over the last year, the team also has been gearing up to deliver the final data products from the Kepler [prime] mission. Today marks an important milestone: the final Kepler Object of Interest (KOI) table has been delivered and made available to the community at the NASA Exoplanet Archive. The KOI table contains a list of notable objects that show evidence of astrophysical transit events. The release of these data will help the community plan follow-up studies while our final analyses are completed. A paper detailing the mission’s final candidate catalog is anticipated this summer.

At this time of year, the original Kepler field of view rises in the night sky allowing scientists to carry out their follow-up studies of these KOIs using ground-based telescopes in the northern hemisphere.

Beginning April 1st, the Kepler/K2 guest observer office will be under the direction of Dr. Geert Barentsen. Geert will lead the team’s efforts to engage and support the broader scientific community using data from the K2 mission. He joined the team in June 2015 and has been instrumental in shaping the diverse portfolio of observation targets for the K2 mission. Geert also organized the first-of-its-kind microlensing experiment for NASA—a collaborative survey between the K2 mission and ground-based observatories around the world. Community engagement and the results of the study serve as a proof of concept for NASA’s Wide-Field Infrared Survey Telescope, to be launched in the mid-2020s. Geert is currently organizing another K2 mission campaign focused on the study of supernovae, which is scheduled to begin in December.

With this new appointment, the team bids farewell to Dr. Tom Barclay, our current director of the Kepler/K2 guest observer office, as he begins a new opportunity as the deputy director of the guest investigator office for NASA’s next planet-hunting mission, the Transiting Exoplanet Survey Satellite. Tom joined the team in March 2011 and was promoted to director in October 2014. He led the efforts to engage the scientific community on a new and unexpected opportunity that would become the K2 mission. In July 2016, his leadership and passion for the search for other worlds was recognized with a NASA Ames Honor Award for his exceptional efforts. We applaud Tom’s enthusiastic and tireless work as the Kepler/K2 guest observer director. He will be missed.

The spacecraft remains healthy and productive–a true explorer as it recently completed its eighth full year in space. It now trails Earth by 84 million miles in its tour around the sun. That’s about 452 light-seconds for those spatially inclined, or 0.9 AU for folks that like smaller numbers.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: K2 Marching On With Campaign 11

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Kepler’s K2 mission is now in the midst of its eleventh campaign, observing a patch of sky in the direction of the constellation Sagittarius. During this campaign, it will observe 14,250 new targets, including the Galactic Center and Saturn’s moons Titan and Enceladus.

Campaign 11 began on Sept. 24, but was interrupted for three days (Oct. 18-20) to make a small pointing correction to accommodate the imbalance that was created by broadcasting data from a different antenna on the other side of the spacecraft. Although the spacecraft is as big and heavy as an SUV, it actually turns slightly when we change the broadcasting antenna. This is like having your car begin to turn from the force of the blinking of your turn signal. Yes, the spacecraft is that delicately balanced! Data collection for Campaign 11 will continue until Dec. 7.

Since my last update, our investigation into the cause of the spacecraft’s photometer—the onboard camera—being powered off in July during Campaign 10, confirms that that science detector Module 4 failed. The likely cause was a random part failure that resulted in a high electric current in the circuitry, which blew the protection fuse, disabling the detector but preventing the problem from propagating to other detectors. As part of the fault protection response, the photometer was powered off.

Eighteen of the 21 science detector modules remain fully operational. Two science modules had failed previously: Module 7 in January 2014 and Module 3 in January 2010. These are not unexpected events as the spacecraft ages in the harsh environment of space.

Kepler photometer modules

The comparison of two full frame images from the Kepler spacecraft show two black squares (Modules 3 and 7) and 19 red squares on the left. On the right, there are three black squares (Modules 3, 4 and 7) and 18 red squares. A red square indicates that data is being collected by the photometer and a black square indicates no data is being collected and that the module is no longer functional. Eighteen of the 21 science detector modules remain fully operational.
Credits: NASA Ames/W. Stenzel

In September, the spacecraft had a unique opportunity to provide a ‘wide-angle’ view of comet 67P/Churyumov–Gerasimenko, making observations of its core and tail. These observations complement the close-in study of the comet provided by the European Space Agency’s Rosetta spacecraft during the final month of its mission. These and the remainder of Campaign 10 data have been downlinked to the ground and are being processed for release at the public archive later this month.

We’ve also made changes with the Kepler and K2 project scientist personnel.

Natalie Batalha, astrophysicist and project scientist for NASA's Kepler mission

Natalie Batalha, astrophysicist and project scientist for NASA’s Kepler mission

On Aug. 15,Natalie Batalha, project scientist for NASA’s Kepler mission Natalie Batalha was appointed as the project scientist for the Kepler mission. Since 1999, Dr. Batalha has served in numerous leadership roles throughout the mission including deputy principal investigator and science team lead. In addition to her responsibilities with the Kepler mission, Natalie is a co-lead of NASA’s Nexus for Exoplanet System Science Coalition, and serves on the James Webb Space Telescope Advisory Committee. She also serves as a member of the NASA Advisory Council’s Astrophysics Subcommittee, and, in 2013, participated on the task force to define NASA’s 30-year Astrophysics RoadmapEnduring Quests, Daring Visions: NASA Astrophysics in the Next Three Decades.

Jessie Dotson, project scientist for NASA's K2 mission

Jessie Dotson, astrophysicist and project scientist for NASA’s K2 mission

On Sept. 6, Jessie Dotson assumed the role of project scientist for the K2 mission. Dr. Dotson was formerly the deputy science office director for Kepler and, in 2008, established the Kepler Guest Observer Office. Most recently, she served as astrophysics branch chief in the Space Science and Astrobiology Division at NASA Ames. In 2014, Jessie helped formulate the Asteroid Threat Assessment Project (ATAP) at NASA Ames to quantify the risk to Earth of an asteroid impact. She currently leads the ATAP asteroid characterization team. In 2016, Jessie was awarded a NASA Outstanding Leadership Medal for her work as the astrophysics branch chief at Ames.

Together, Natalie and Jessie replace Steve Howell who served as Kepler project scientist since 2010 and K2 project scientist since mission conception in 2013. In that role, Steve oversaw Kepler science operations through the end of its prime mission, the recovery from the reaction wheel failure that nearly ended the mission, and the development and implementation of the K2 mission that gave Kepler a new lease on life. We commend Steve for his work as the Kepler/K2 project scientist, with notable leadership in catalyzing the science community to support Kepler’s extended mission called K2.

In August, the team gathered for the annual year-in-review of spacecraft operations with Ball Aerospace, the designer, manufacturer and flight controller of Kepler. A topic of high interest is the on-board fuel reserve, which is expected to last into the spring of 2018.

At last count, Kepler has identified more than 5,100 planet candidates. Of these, more than 2,500 have been verified as bona fide planets. NASA’s next planet-hunting mission, the Transiting Exoplanet Survey Satellite (TESS), is scheduled to launch no later than June 2018. TESS will build upon Kepler’s success and search for exoplanets around the stars closest to the own solar system.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: Photometer Update

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As reported in last week’s update, the Kepler spacecraft’s photometer—the onboard camera—was commanded to return to science after being found to be off during a routine contact on Thursday, July 28. Yesterday, the team confirmed that the photometer responded as expected and began collecting data again on Tuesday, Aug. 2.

Yesterday’s scheduled contact with the spacecraft was made using the 70-meter dish at NASA’s Deep Space Network (DSN) at Goldstone, California. The large dish provided the necessary communications link with the spacecraft to confirm Kepler was back doing science.

The Kepler focal plane

The Kepler focal plane is approximately one foot square. It’s composed of 25 individually mounted modules. The four corner modules are used for fine guiding and the other 21 modules are used for science observing.
Credits: NASA Ames and Ball Aerospace

Our investigation of the cause centered on the focal plane detector modules. The signature of the recorded faults surrounding the anomaly was reminiscent of an event in January 2014, when one of the science detector modules (Module 7) failed. In that case, we concluded that the most likely cause was a random part failure that resulted in a high electric current in the circuitry, which blew the protection fuse, disabling the detector but preventing the problem from propagating to other detectors. As part of the fault protection response, the photometer was powered off. Thus, it seemed likely that this most recent anomaly might be the result of another random detector failure—something to be expected as we continue to extend the spacecraft’s mission.

Analysis of the temperature data from the focal plane seems to bear out this hypothesis, and points suspicion to science detector Module 4, as the likely culprit. When we turned the photometer back on, all the other modules warmed up at a consistent rate, while Module 4 reacted more slowly, and never reached full operating temperature before the DSN contact ended.

As part of our standard contact procedures yesterday, we brought down a few pixels from the focal plane to verify the precise pointing of the spacecraft, and some of these pixels were from the suspect Module 4. The data from these pixels failed to register its assigned target star, while pixels from other modules produced the expected signals from their assigned target stars. Therefore we are relatively certain that this detector has indeed failed.

For the K2 mission’s current Campaign 10, the targets that were assigned to Module 4 will yield no further science results. For the campaigns going forward, we will select targets which fall on the remaining operational detectors, which will have little to no impact to the upcoming science.

Such hardware failures were foreseen in the initial mission planning, and the system design is robust and compartmentalized to minimize the impacts. After more than seven years in the harsh conditions of space, 85 percent of Kepler’s original detectors are still operating. Module 4 will be the third of the 21 science modules to have failed in-flight.

Kepler’s primary mission ended in 2013 but exoplanet and astrophysics observations continue with the K2 mission, which began in 2014. In June, NASA Headquarters announced that Kepler is to continue science operations through the end of the FY19, by which time the on-board fuel is expected to be fully depleted.

To-date, Kepler has identified more than 5,100 planet candidates, of which 2,454 have been verified as bona fide planets. NASA’s Transiting Exoplanet Survey Satellite, scheduled to launch in 2017 or 2018, will continue Kepler’s success and search for exoplanets closer to our own solar system.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: K2 Campaign 10

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During a scheduled contact with NASA’s Kepler space telescope on Thursday, July 28, the team found the photometer—the camera onboard the spacecraft—powered off. The photometer was turned on again and the flight system returned to autonomous science operations on Monday, Aug. 1. We will confirm that science operations have been resumed within a week. The team is currently investigating the cause; the spacecraft is otherwise operating normally.

The Kepler spacecraft is currently in the tenth observing campaign of its second mission, called K2. Kepler’s primary mission ended in 2013 but more exoplanet and astrophysics observations continue with the K2 mission, which began in 2014. To-date, the K2 mission has identified more than 450 new planet candidates, of which 128 have been verified as bona fide planets.

In June, NASA Headquarters announced that the K2 mission is to continue science operations through the end of the FY19, by which time the on-board fuel is expected to be fully depleted.

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Mission Manager Update: K2 Marches On

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The K2 mission, the two-wheel operation mode of the Kepler spacecraft observing in the ecliptic, is exhibiting no discernible ill effects since the recent Emergency Mode, other than the extra fuel usage. K2 is now in the second half of the special microlensing campaign called Campaign 9. The first half of the campaign was shortened by two weeks as a result of the emergency, and the data acquired have made public. The microlensing team has already been searching for the telltale events that indicate an object passing in front of a background star, identifying approximately two-dozen of these lensing events. Thus far, the experiment seems to be a smashing success!

While we are still dotting the i’s and crossing the t’s on the cause of the emergency, all the signs are pointing towards a single bit that changed state in the memory of an electronic chip that controls the internal command and data bus onboard the spacecraft. The memory was designed to be highly resistant to upset but if a high-energy cosmic ray hit in just the wrong place or at the wrong time in a write cycle an upset can occur. In this case, the upset caused a disruption in the internal data stream, passing invalid data sets to the flight computer, setting off several fault responses including the shutdown of critical heaters on the spacecraft. After a couple of hours, propellant froze in the propulsion system effectively disabling pointing control. Without pointing control, the spacecraft slowly drifted until the sun got too close to a “forbidden zone” around the optical axis of the telescope, causing the Emergency Mode to kick in and protect the telescope. While we have an excellent fault protection system onboard, no amount of pre-planning is going to work if we get multiple, random faults, which is why we have the Emergency Mode in the first place. And it worked beautifully!

The spacecraft emergency provided an opportunity to highlight the important role that engineering plays behind the scenes in the development and operation of a mission. Last month the engineers from NASA Ames, Ball Aerospace and the Laboratory for Atmosphere and Space Physics at the University of Colorado, both located in Boulder, who all worked on the recovery of the spacecraft, participated in a Reddit “Ask Me Anything.” The team had a fantastic time responding to the online community’s questions about the steps in the recovery and the experience of working through a high-pressure, high-visibility situation. We were encouraged by the level of interest and look forward to welcoming more problem solvers to the field of engineering. You can learn more about managing the recovery of a spacecraft 75 million miles from Earth in a recent question and answer feature.

Meanwhile the scientific results from the missions keep rolling out. Last month Dr. Timothy Morton of Princeton University announced that his analysis of the Kepler data was able to validate planethood for 1,284 more of Kepler planet candidates. The Kepler verified planet count currently stands at 2,327.

Now in its ninth observing campaign, K2 continues to produce a bounty of data for the scientific community to continue the search for exoplanets and to study planet and star formation, as well as the explosive death of red giant stars, commonly known as supernovae. The K2 planet count continues to climb, reaching more than 250 candidates, of which nearly 50 have been verified as bona fide planets.

NASA has also announced today that K2 is to continue science operations through the end of the FY19, by which time the on-board fuel is expected to be fully depleted. The mission extension, based on a recommendation from NASA’s Astrophysics Division’s 2016 Senior Review of operating missions, provides two additional years of funding for K2 to continue exoplanet discovery, and the study of notable star clusters, young and old stars, active galaxies and supernovae. For more details about the recommendation and for a listing of other missions approved for extension, see the 2016 Senior Review report.

With the emergency behind us, and fuel to last us into the summer of 2018 or beyond, the news of the two-year mission extension was a welcomed vote of confidence in the team. This news comes just a week after K2 completed two years of operations, celebrating its second “birthday.”

Regards,

Charlie Sobeck
Kepler and K2 mission manager
NASA’s Ames Research Center

Science Team Spotlight

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Pavel Machalek, Ph.D. 

Data scientist, Kepler Mission 
A Day In The Life 
PPavel Machalekavel Machalek is a data scientist for the Kepler Mission. Prior to joining the team, he obtained his own funding to work on the Spitzer Space Telescope using infrared photometry to investigate Hot Jupiters, studying their temperature and structure. For Kepler, he is currently working on light curve settings for the photometer, detecting high precision photometry of Hot Jupiters as they travel behind their star. A good portion of Pavel’s day is spent troubleshooting issues, searching out possible defects in Kepler’s photometry. This work contributes to the day-to-day operation of the satellite. He and other data scientists must ensure that the data products streaming from the satellite are still valid on a bi-weekly, monthly and quarterly cycle in an iterative process to ensure that the photometer’s data runs smoothly. When necessary, he works closely with the Science Operations Center (SOC) to improve the software code and resolve issues. Pavel also helps produce documentation for both the pipeline and the public data release notes and is beginning to collaborate with the team on the Kepler scientific papers. 
Meaning of the Mission 
“The number one goal is to find a habitable planet, a second Earth; this mission doesn’t have the capability to discover life on an Earth-like planet, just the capability to discover a planet that lies in the habitable zone. This mission will also discover how frequently these rocky planets occur. I believe the idea of denouncing the possibility of a unique single Earth is an atheistic crusade; it is a way to fight back against religious dogmatism. It would be interesting to find out whether our Earth is the only one in the Universe or whether there are many others. In particular, it would be fascinating to contrast age-old and firmly held theological beliefs regarding the uniqueness of the Earth and our place in the Universe to the tantalizing possibility that there could be dozens, hundreds or even thousands of other worlds similar to our own.” 
To read Pavel’s biography, click here
By Kepler blog contributor, Marlowe Primack.

Guest Observer Program Spotlight

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Martin Still, Ph.D.  

Director, Kepler Mission Guest Observer Program

Kepler’s primary scientific goal is to detect terrestrial planets in the habitable zone and the frequency in which they occur, however, the data the photometer is providing the scientific community reaches far beyond the search for exoplanets.  In order to get a sense of Kepler’s depth I sat down with Martin Still, Director of the Guest Observer Program and newly appointed Deputy Science Office Director.

A Day in the Life 
What stands out to Martin more than any job he has had previous to this is that no one day is exactly alike. “No matter what you have planned for your day you don’t always get it done because there’s a new issue to resolve as soon as you arrive at work, this has to do with working on a new mission. The mission is unique and novel so operational experience is being learned on the fly rather than inherited from past projects. Every day is filled with learning how to do new things and unlearning how to do old things. The overarching feeling as the weeks and months go by is that we are making grand waves. I have enjoyed watching the project evolve; it has grown considerably. When I started a year ago, the startup job within a small team was much more hands on; at this point, with new recruits onboard I’m able to spend more time scoping and directing our efforts. I’m now able to take a step back, draw breath and lean on the support of both the existing team members and a lot of new people who have joined the mission. They have come in with research experience whether it’s exoplanet or timing related astrophysics, these new team members are really good at what they do. I’m there to scope out their work, make sure that their path ahead is clear and that they have all of the resources that they need. Somewhere between one half to three quarters of my day is spent in a management or operations meeting of one description or another. The rest of the day is spent making sure everyone is happy and they can get on with their work, driving towards our mission goals.”

GO Program Overview 
The Guest Observer Program  can be seen as a facilitator with a two-way door. In order to be successful we have to be a clearinghouse for much of the mission’s operational information. If you are an astrophysicist working at a university or an institution anywhere in the world and you want to be able to do science with Kepler it takes enormous understanding of the capabilities of the mission. You have to know its strengths and limitations; when you’re looking at Kepler data you need to be able to recognize what is astrophysical signal and discriminate it from instrumental artifact. Anyone who chooses to participate needs to collaborate with the Guest Observer Office so they understand as much of the technical information as possible and each participant knows what they can get out of the mission. The Guest Observers reach out and ask for help in understanding a piece of information out of that data. The program’s success is judged by the amount of scientific papers that are being produced, the number of universities working on Kepler data and the number of scientists aware of the mission and what it can do.” 

GO Proposal Process
“Guest observing is based around peer reviewed science proposals. In order to write a successful proposal you have to be an expert in your field.  Amateur astronomers are not excluded from the program at all, however, the best advice they can get is to collaborate with a professional astronomer since they are in the business of writing competitive scientific proposals. The panels that decide what programs get followed and what targets get observed look for any reason to throw a proposal out because there are so many good ones to choose from—it’s very much survival of the fittest. If Kepler doesn’t observe the most competitive and the most exciting science it will struggle in the future. Each proposal has to be more compelling than the next.  If one wants to become a Guest Observer you would submit a proposal with a very well-defined scientific goal and propose to answer a specific scientific question. The most compelling questions are the ones that will be chosen. When it’s time to choose among the proposals, NASA headquarters and the Guest Observer office collaborate to lobby the scientific community to provide independent scientific advisors. They discuss each proposal on merit in a closed room full of cookies and coffee. Each person has an equal vote; seven or eight experts make the decision. These experts come from all over the country and even the world.  In order to keep the process fair and unbiased the panel changes every year. It’s made up of a mix of senior experts and new young post-docs with a huge spectrum of scientific interests and ideas. The goal is to have the best mix of professional astronomers that can be found.”  

Exciting Discovery!
A paper that appeared in the press recently is a discovery made by Kevin Apps, a 25 year old undergraduate from the UK who found a new brown dwarf object by mining Kepler’s public data. Martin explains, “A brown dwarf is somewhere between a gaseous planet and a star. It’s a cold star, just a few thousand Kelvin in temperature. This brown dwarf is only the fifth transiting brown dwarf known to exist. Not only that, its transit shape has been fit with a model and its mass measured by ground-based spectroscopy. Because of the photometric accuracy of Kepler, the measured radius of this brown dwarf is many times more accurate than any of the other four discovered. This discovery is wonderful for Kepler and for the amateur astronomer. It shows that there is potentially a problem in the theory of brown dwarf atmospheres. The observation does not fit current theories of brown dwarf size, being too large for an object of its perceived age. Kevin called on prolific professional planet-hunters to put this discovery into a paper.” In Martin’s view this is one of the most exciting papers that has come out of the Kepler community outside of the Science Team and exoplanet world. “This is what I love to see and why the Guest Observer program is so important. Kepler’s endeavors cannot be performed by the Science Team alone, there’s just too much work to be done.”

Personal Science
Martin did his Ph.D. in the field of cataclysmic variable stars. “These things are wonderfully dynamic in terms of the way they changed rapidly over time. They are binary stars orbiting very close to each other on a few-hour time scale, flashing past each other, they’re so close that one of the stars is actually grabbing material from its neighbor and you get this bridge of gas between the two. This gas is falling onto what is called the accretor, which is a white dwarf star whose surface undergoes regular ‘cataclysmic’ explosions. These were fantastically sexy objects to work on back in the 70’s and 80’s with great relevance to the formation of planets, stars and black holes, but as time went by, accretion disk theory overtook the observational capabilities of ground-based and space-based telescopes; it overshot it dramatically. The only way that many people, myself included, believed that we were going to catch up is to have a 100-meter telescope on the ground—a super telescope, equipment that will not be available for at least another decade. When I joined the Kepler team, this mission’s ability to open a unique and valuable new window on these objects was immediately apparent. The first thing I did was to ask the target schedulers to put apertures over the few cataclysmic variables that are in Kepler’s field of view. These things are quite ubiquitous, there are thousands of them that we know of in the galaxy but most of them are quite faint including the ones in Kepler’s FOV. There were none that stood out, no fantastically brilliant ones that were famous and that people always worked on over previous decades. They had barely been looked at. However, when the data came through it was amazing, these data have enormous value. I was back to being a cataclysmic variable fan. Kepler is doing something unique that no other telescope can do, it’s sparking enthusiasm in this field and a body of critical work.”

Martin Still, Director of Kepler's Guest Observer Program
 
Emotional Response
The data that Kepler is providing has actually brought tears to the eyes of scientist. The first time Martin saw a light curve of one of these cataclysmic variable discs he admits that he “got a bit misty; Kepler evokes an emotional response in many people. The final product of the Kepler observations of cataclysmic variables could be putting a value on a particular number that is extremely important across the whole of astrophysics and that’s how ‘sticky’ what we call an accretion disk is. The reason why this is so important is that almost everything in the universe formed out of an accretion disk. Stars formed, planetary systems around stars formed from within these disks. These disks also surround the massive black holes around active galactic nuclei.  Kepler is observing accretion disks with a combined photometric precision and time sampling that nobody has ever been able to do before. While it’s not producing scientific quantities that haven’t been estimated before, it is improving the accuracy of what we know about these accretion disk properties by an order of magnitude, which is a big step forward.”

Kepler’s Contribution to Stellar Activity
“One of the things that Kepler does really well, not necessarily because of its photometric precision but because of its ability to stay on the same piece of sky observing the same stars, is that it’s producing an enormous legacy catalog of spotty stars; just like our Sun has sunspots that come and go on an eleven-year cycle. Sometimes the Sun is very spotty around the equator; it has a lot of dark patches, which are related to the magnetic activity within the Sun being generated by convective motions below the surface. Many other cool low-mass stars for which the Sun is included have a similar mechanism going on across their surface layers. Kepler can actually see star spots on distant stars developing and going away. You can use the spots on the star’s surface to measure the rotation speed of the star, which is very important parameter in the life of a star. Young stars rotate very rapidly; they formed out of a cold cloud and they spin very fast when they are young. As they mature and get older they slow down and become more sedate. As they become more sedate the number of spots gets smaller. What Kepler gives us is a wonderfully broad look at the evolutionary state of a star. What will be truly amazing is if Kepler continues its mission beyond the primary years through 2012. If it gets another two or three years, just a little bit longer, then you approach the time scales of the magnetic activity cycles. The Sun is eleven years; many stars are less than 5 years. This kind of opportunity to observe these stars has never been provided before, being able to take 30-minute cycle samplings of highly precise photometry of one star or thousands of stars for five or six straight years would be unprecedented. We will be able to see the activity cycles of thousand and thousands of stars, which will be awesome.” 

The Depth of Kepler
“We can only infer the structure and property of a star from what we see on the surface. This requires both observation and theoretical modeling to record what the surface of the star looks like. In that process there’s always redundancy. Kepler has the ability and the accuracy to record in great detail and precision the ways and modes of surface pulsation across many stars. Nothing else on or off the planet can do it with anywhere near the same degree of fidelity. These pulsations are basically driven by areas of instability, storms on or close to the surface, on the surface or even deep down in the core of the star. When you see these pulsations it’s a direct measure of things that are going on either deep in the interior or close to the surface of the star. There are phenomena you wouldn’t be able to detect on the surface of the star any other way, other than Kepler. It’s the only instrument that can do this work that precisely for that duration of time. This isn’t a new field of study.  People have been doing this work from the ground and from space for decades.  However, Kepler has blown the field wide open! It is still model dependent, you have to provide the theory to explain the observation and it’s the theory that tells you about the structure of a star. However, because the observations are that much more precise, the theory has to be that much more precise. Before Kepler there may have been five theories to explain what you were seeing, perhaps now there are only one or two. And of course that’s not to say the theory is correct. In science your theory only stands until proven incorrect. The other thing that Kepler is going to do over the years is to build a legacy database and those theories, every day, week, month and year still have to explain what you are looking at and if they can’t, they’re wrong. Kepler is driving this field of science and is teaching us more about the interior of stars. It’s like a rapid injection of understanding; things that might take decades to understand without Kepler will be learned on a much shorter time scale.” 
 
Meaning of the Mission
I was curious to know what it would mean to Martin if Kepler were to find an “Earth-like” planet. “I fully appreciate that my personal views are heretical, but that’s why I was asked to run the Guest Observer Office, I don’t see exoplanets as the richest area of science that Kepler is pursuing.  While time may prove me wrong, I feel that the habitable zone exoplanets that Kepler is searching for are almost certainly there.  Their discovery is inevitable within the next few years either by Kepler or another project. For me, the beauty of Kepler is the other science that it’s doing.  It’s re-exciting areas of astrophysics that have been quiet over the last 20 years, and promoting those areas which have been noisy but is contributing to them in new, significant ways, providing that extra step. If we are being honest and truthful with ourselves, the exoplanet mission provides enormous interest for the general public. However, in terms of NASA’s mission to understand the origin and structure of our universe, Kepler’s other activities provide a legacy which history may well regard to be of equal scientific importance.”  Martin loves working with the Kepler team, “It’s a fantastic environment to work in, who wouldn’t be excited to work on this mission.”  To read more about Martin’s educational background and prior work experience, click here.  

By Kepler blog contributor, Marlowe Primack


Science Team Spotlight

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Jeffrey Van Cleve, Ph.D.

Photometer Characterization Scientist for the Kepler Mission 


A Day in the Life

Jeffrey Van Cleve spends much of his time looking at data that Kepler is about to release to MAST, the Multimission Archive at the Space Telescope Science Institute. MAST supports a variety of astronomical data archives, with a primary focus on scientifically related data sets in the optical, ultraviolet, and near-infrared parts of the spectrum.  Jeff and other members of the Kepler Data Analysis Working Group (DAWG) participate in this data review in order to verify that the Kepler Science Processing Pipeline performs as expected in most cases, and to understand the exceptions.  A different part of his day might be spent working on an important and interesting linear algebra puzzle to improve the Pipeline. This is one of Jeffrey’s favorite aspects of his work.  


Another of Jeffrey’s tasks is working on file formats and coordinate system conventions for the MAST archive. He feels a “sense of mission that Kepler leave behind a legacy that people can use long after the mission is over to get some great science done. For example, even if almost every star system has a planet like the earth, more than 95% of Kepler’s targets will not show planets for geometrical reasons — a huge treasure trove of precise stellar light curves for astrophysical investigation. ”He and 4 or 5 other people who call themselves the FITS Fanatics work on this and though it might seem kind of dull to have lengthy discussions about file formats and header keywords, it is part of leaving behind a legacy which will make it easy for people to use and publish the data. Part of this process is to make the headers self-explanatory, so that they describe in detail how the data was collected, calibrated, and formatted.

To help with this work, two new members have been hired in the science office to work on the release notes, eventually taking over editing them and generating tables and figures. The bonus? Jeffrey will have more time to work on linear algebra puzzles!

Kepler’s Achievement

What’s the most remarkable aspect of Kepler’s performance as an astronomical instrument? “It was the photometric precision of the CCD (visible light) sensors and the stability of the telescope pointing. It is amazing, when you think about it, that we can do 20 parts per million photometry, which requires both very stable CCDs and the ability to point the telescope to a millionth of a degree. It’s like looking at a light bulb 100 km (60 miles) away and being able to tell if a gnat is flying around it.”  


Meaning of the Mission

I was curious to know what Kepler’s existence means to Jeffrey on a personal level. “The prevalence of habitable worlds, as measured by Kepler, helps us assess the probability of finding intelligence in other star systems in our Galaxy. What I really appreciate about Kepler is that it allows me to contribute to an optimistic vision of the human future, one that includes colonizing planets in other star systems, or communicating with intelligent species that have survived the perils we currently face. Their existence alone would be a beacon of hope.”

To read Jeffrey Van Cleve’s full biography, click here

By Kepler blog contributor, Marlowe Primack

The Leitmotif of this Quarter's SWG Meeting: Validation versus Confirmation

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The Kepler Science Team is scattered all over the US (excepting our two colleagues that help to run the Asteroseismology Consortium… from Denmark!).  Because of the distance, teleconferencing technology and platforms like webex for sharing computer desktops are as essential as the computers used to analyze the data.  But sometimes no technology can replace a room full of brainpower all attacking the same problem or contemplating the same question.  Maybe it’s just the smell of coffee and donuts or the inspiration derived from watching your colleague’s facial expressions.  The reality is that more gets done when we’re all in the same room.  So a few times each year, the team members pack up their laptops, hop on planes, and gather at the home institution of whomever happens to be taking his or her turn as the designated host.  This week, the team gathered at NASA Ames Research Center in Mountain View, California.  We call these our “Science Working Group” meetings,  more lovingly referred to as SWG (“swig”) meetings.
The first order of business is to hear status reports.  How is the instrument performing?  What does the budget look like going forward (as if we don’t already know the answer to that question)? What can we expect from future software releases and when can we expect them?  We learned that the spacecraft has been free of safe mode events for almost 8 months now.  This is very good news.  With more than a year of data under our belt, we’ve learned a lot about the performance of the instrument.  We see seasonal changes in the focus, for example, that are driven by the amount of sunlight striking the backside of the spacecraft.  Varying sunlight levels induce slow temperature changes that affect the focal length of the photometer.  The amplitude of the variation and its effect on the data is well within our tolerances.  There is no indication that we’ll lose any more modules.  
The various working groups then share what they’ve accomplished over the last months.  We heard a report, for example, from the Eclipsing Binary Working Group.  Their goal is to produce an updated binary catalog using four quarters of data within the next 6 months.  We are counting on them to tell us, statistically, how many binary stars of a given period and apparent brightness we expect to see — a number which helps us to understand how often we expect to find astrophysical signals in our data that mimic planet transits.  We must understand this number well because most of our planet candidates will NOT be confirmed in the traditional sense — by way of high precision radial velocity  measurements that give us the mass of planet.  The catalog of planets that Kepler produces will be probabilistic in that every candidate will have an associated likelihood that the planet interpretation is correct.  This is new territory we’re charting.  It will lead to a new type of discourse on exoplanets in our galaxy.  Someone wondered out loud how the public will react to the announcement of a new world… “with a 95% likelihood”.  As he asks the question, I’m picturing the fine print on my wireless phone bill, and I’m hearing the guy at the end of the commercial who uninteligibly rattles off the litany of horrible side-effects that said medication can produce.  That’s not a path we want to take.  We’ll be asking the public to contemplate the Universe in a statistical sense, and it might get ugly.
The team devoted a good fraction of its time discussing how these “likelihoods” will be computed.  There are challenges ahead.  A small committee will meet with the folks over at the Ames supercomputing facility to talk about ways to speed up the number crunching that will be required.  We’ll likely have to revisit our priorities for utilizing highly competitive time on telescopes like Keck, WIYN, and the MMT.  These discussion were kicked off by a talk that Jack Lissauer gave.  The title of his talk became the leitmotif of the meeting: “Validation versus Confirmation”.  We realize that there are issues we are only beginning to fully appreciate.  This does not discourage us.  To the contrary, it motivates us.  This is the scientific method at its best.  As we each head back to our home institutions, we know what to do.
Natalie Batalha
Deputy Science Team Lead, San Jose State University
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For two days, members of the Kepler Science Working Group filled the air in the meeting room with descriptions of their work on the pixels, the pipelines, and the planets.   What impressed me most was the long hours and technical expertise everyone was contributing toward the still-absurd goal of finding and characterizing the first Earth-sized planets.
The folks on the team are critically examining and improving the instruments, software, and performance of every aspect of the Kepler mission, down to truly invisible minutia.   Some members are devoted to studying and minimizing electronics noise in the 94 megapixel light detector.  Others are optimizing spacecraft stability.  Some are dedicated to improving Kepler’s phenomenal photometric performance, working toward Kepler’s amazing goal of 20 parts per million.   And some are observing Kepler “Objects of Interest” at ground-based telescopes by night, attending the meeting by day, and then going back to the telescope each night, all to verify and measure the planet candidates Kepler has identified.   Just archiving all the information about the hundreds of “Kepler Objects of Interest” is a monumental task.
In the end, I felt fortunate to be a part of the camaraderie.  The meeting room was filled with a warmth of shared purpose.  Everyone is working with mutual appreciation of the enormous challenges and personal sacrifices needed to get the job done. And everyone was swept along by the unprecedented hope of placing our home planet in its proper cosmic context.
Geoff Marcy
Co-Investigator, UC Berkeley
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It was exciting to see how much work has been accomplished and overwhelming to see how much work still needs to be done.  It was surpising to see so many new faces – the number of collaborators and contributors continues to grow – which is a very good thing.  On Wednesday, the day after the science team meeting, there was an all-day session to discuss the follow-up observations of individual candidates.  The participants  rolled up their sleeves and worked extremely hard all day.  By mid-afternoon it looked like the group had been locked up for a week – there were computer cords, styrofoam cups, jackets and sweaters, half-eaten doughnuts, empty soft-drink cans, and miscellaneous debris strewn everywhere, as people had not even left to get lunch.  The single-mindedness, dedication, and teamwork demonstrated by the scientists as they struggled to interpret the myriad observations on a plethora of candidate planets was a joy to behold.


Michael Haas
Science Office Director, NASA Ames Research Center


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As a member of the Follow-up Observing Team, my days(and nights) are focused on collecting astronomical data that contributes to our understanding of the potential planets that Kepler finds. Since my work is focused on extending what Kepler finds, I forget that dozens of people are working on every detail of the Kepler project. Nearly all of the people at the SWG meeting need to complete their work, before I can do my own. From satellite communication, to public outreach, to nitty gritty pixel-level analysis, the amount of work that goes into Kepler is absolutely amazing.
Watching all the entire Kepler picture be painted was remarkable.
Howard Isaacson
Kepler Collaborator, UC Berkeley

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